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Found 3546 results

  1. So, i'm still on my quest to unterstanding the intricacies of HDR and implementing this into my engine. Currently i'm at the step to implementing tonemapping. I stumbled upon this blogposts: http://filmicworlds.com/blog/filmic-tonemapping-operators/ http://frictionalgames.blogspot.com/2012/09/tech-feature-hdr-lightning.html and tried to implement some of those mentioned tonemapping methods into my postprocessing shader. The issue is that none of them creates the same results as shown in the blogpost which definitely has to do with the initial range in which the values are stored in the HDR buffer. For simplicity sake i store the values between 0 and 1 in the HDR buffer (ambient light is 0.3, directional light is 0.7) This is the tonemapping code: vec3 Uncharted2Tonemap(vec3 x) { float A = 0.15; float B = 0.50; float C = 0.10; float D = 0.20; float E = 0.02; float F = 0.30; return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F; } This is without the uncharted tonemapping: This is with the uncharted tonemapping: Which makes the image a lot darker. The shader code looks like this: void main() { vec3 color = texture2D(texture_diffuse, vTexcoord).rgb; color = Uncharted2Tonemap(color); //gamma correction (use only if not done in tonemapping code) color = gammaCorrection(color); outputF = vec4(color,1.0f); } Now, from my understanding is that tonemapping should bring the range down from HDR to 0-1. But the output of the tonemapping function heavily depends on the initial range of the values in the HDR buffer. (You can't expect to set the sun intensity the first time to 10 and the second time to 1000 and excpect the same result if you feed that into the tonemapper.) So i suppose that this also depends on the exposure which i have to implement? To check this i plotted the tonemapping curve: You can see that the curve goes only up to around to a value of 0.21 (while being fed a value of 1) and then basically flattens out. (which would explain why the image got darker.) My guestion is: In what range should the values in the HDR buffer be which then get tonemapped? Do i have to bring them down to a range of 0-1 by multiplying with the exposure? For example, if i increase the values of the light by 10 (directional light would be 7 and ambient light 3) then i would need to divide HDR values by 10 in order to get a value range of 0-1 which then could be fed into the tonemapping curve. Is that correct?
  2. Hello, everyone! I hope my problem isn't too 'beginnerish'. I'm doing research on motion synthesis now, trying to implement the Deep Mimic paper (DeepMimic) by BINPENG XUE, in this paper, I need to first retarget character A's motion to another character B to make the reference motion clips for character B, since we don't have character B‘s reference motion. The most important thing is that in the paper, the author copied character A's joint's rotation with respective to joint's local coordinate system (not the parent) to character B. In my personal understanding, the joint's rotation with respective to joint's local coordinate system is something like that in the attached photo, where for the Elbow joint, i need to get the Elbow's rotation in the elbow's local coordinate system (i'm very grateful for you to share your ideas if i have misunderstanding about it 🙂) I have searched many materials on the internet about how to extract the local joint's information from FBX, the most relative one i found is the pivot rotation( and geometric transformation, object offset transformation). I'm a beginner in computer graphics, and i'm confused about whether the pivot rotation( or geometric transformation, object offset transformation) is exactly the joint's local rotation i'm seeking? I hope someone that have any ideas can help me, I'd be very grateful for any pointers in the right direction. Thanks in advance!
  3. Hey My laptop recently decided to die, so Ive been transferring my project to my work laptop just to get it up to date, and commit it. I was banging my head against the wall all day, as my textures where not displaying in my program- I was getting no errors and no indication of why it was occurring so I have been just trying to figure it out- I know the image loading was working ok, as im using image data elsewhere, I was pretty confident that the code was fine also, as ive never had an issue with displaying textures before, so I thought it might be the drivers on this laptop, (my old one was just using the built in IntelHD, while this laptop has a NVIDIA graphics card) but all seems to be up to date. Below are my basic shaders: Vertex Shader #version 330 core layout(location = 0) in vec3 position; layout(location = 1) in vec3 color; layout(location = 2) in vec3 normal; layout(location = 3) in vec2 texCoord; uniform mat4 Projection; uniform mat4 Model; out vec3 Color; out vec3 Normal; out vec2 TexCoord; void main() { gl_Position = Projection * Model * vec4( position, 1.0 ); Color = color; Normal = normal; TexCoord = vec2( texCoord.x, texCoord.y); } Fragment Shader #version 330 core in vec3 Color; in vec3 Normal; in vec2 TexCoord; uniform sampler2D textureData; void main() { vec4 textureColor = texture( textureData, TexCoord ); vec4 finalColor = textureColor * vec4( Color, 1.0f); gl_FragColor = finalColor; } Calling Code glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, textureID); glUniform1i(glGetUniformLocation(shaderID, "textureData"), textureID); Now this is the part i dont understand, I worked through my program, until I got to the above 'Calling Code'. This just displays a black texture.. my original issue. Out of desperation, I just tried changing the name in glGetUniformLocation from "textureData" to "textureData_invalid" to see if my error checks would through up something, but in actual fact, it is now displaying the texture as expected. Can anyone fathom a guess as too why this is occurring.. im assuming the random text is just picking up the correct location by c++ witchcraft, but why is the original one not getting picked up correctly and/or not working as expected I realize more code is probably needed to see how it all hangs together.. but it seems to come down to this as the issue
  4. Hello. So far i got decently looking 3d scene. I also managed to render a truetype font, on my way to implementing gui (windows, buttons and textboxes). There are several issues i am facing, would love to hear your feedback. 1) I render text using atlas with VBO containing x/y/u/v of every digit in the atlas (calculated basing on x/y/z/width/height/xoffset/yoffset/xadvance data in binary .fnt format file, screenshot 1). I generated a Comic Sans MS with 32 size and times new roman with size 12 (screenshot 2 and 3). The first issue is the font looks horrible when rescaling. I guess it is because i am using fixed -1 to 1 screen space coords. This is where ortho matrix should be used, right? 2) Rendering GUI. Situation is similar to above. I guess the widgets should NOT scale when scaling window, am i right? So what am i looking for is saying "this should be always in the middle, 200x200 size no matter the display window xy", and "this should stick to the bottom left corner". Is ortho matrix the cure for all such problems? 3) The game is 3D but i have to go 2D to render static gui elements over the scene - and i want to do it properly! At the moment i am using matrix 3x3 for 2d transformations and vec3 for all kinds of coordinates. In shaders tho i technically still IS 3D. I have to set all 4 x y z w of the gl_Position while it would be much much more conventient to... just do the maths in 2d space. Can i achieve it somehow? 4) Text again. I am kind of confused what is the reason of artifacts in Times New Roman font displaying (screenshot 1). I render from left to right, letter after letter. You can clearly see that letters on the right (so the ones rendered after ones on the left are covered by the previous one). I was toying around with blending options but no luck. I do not support kerning at the moment but that's definitely not the cause of error. The display of the small font looks dirty aliased too. I am knd of confused how to interpret the integer data and how should be scaled/adapted to the screen view. Is it just store the data as constant size and again - use ortho matrix? Thanks in advance for all your ideas and suggestions! https://i.imgur.com/4rd1VC3.png https://i.imgur.com/uHrSXfe.png https://i.imgur.com/xRTffPn.png
  5. Hi, I'm a Multimedia Engineering student. I am about to finish my dergree and I'm already thinking about what topic to cover in my final college project. I'm interested in the procedural animation with c++ and OpenGL of creatures, something like a spider for example. Can someone tell me what are the issues I should investigate to carry it out? I understand that it has some dependence on artificial intelligence but I do not know to what extent. Can someone help me to find information about it? Thank you very much. Examples: - Procedural multi-legged walking animation - Procedural Locomotion of Multi-Legged Characters in Dynamic Environments
  6. hello guys , i have some questions what does glLinkProgram and glBindAttribLocation do? i searched but there wasnt any good resource
  7. phil67rpg

    wait loop

    void collision(int v) { collision_bug_one(0.0f, 10.0f); glutPostRedisplay(); glutTimerFunc(1000, collision, 0); } void coll_sprite() { if (board[0][0] == 1) { collision(0); flag[0][0] = 1; } } void erase_sprite() { if (flag[0][0] == 1) { glColor3f(0.0f, 0.0f, 0.0f); glBegin(GL_POLYGON); glVertex3f(0.0f, 10.0f, 0.0f); glVertex3f(0.0f, 9.0f, 0.0f); glVertex3f(1.0f, 9.0f, 0.0f); glVertex3f(1.0f, 10.0f, 0.0f); glEnd(); } } I am using glutTimerFunc to wait a small amount of time to display a collision sprite before I black out the sprite. unfortunately my code only blacks out the said sprite without drawing the collision sprite, I have done a great deal of research on the glutTimerFunc and animation.
  8. I've noticed in most post processing tutorials several shaders are used one after another: one for bloom, another for contrast, and so on. For example: postprocessing.quad.bind() // Effect 1 effect1.shader.bind(); postprocessing.texture.bind(); postprocessing.quad.draw(); postprocessing.texture.unbind(); effect1.shader.unbind(); // Effect 2 effect2.shader.bind(); // ...and so on postprocessing.quad.unbind() Is this good practice, how many shaders can I bind and unbind before I hit performance issues? I'm afraid I don't know what the good practices are in open/webGL regarding binding and unbinding resources. I'm guessing binding many shaders at post processing is okay since the scene has already been updated and I'm just working on a quad and texture at that moment. Or is it more optimal to put shader code in chunks and bind less frequently? I'd love to use several shaders at post though. Another example of what I'm doing at the moment: 1) Loop through GameObjects, bind its phong shader (send color, shadow, spec, normal samplers), unbind all. 2) At post: bind post processor quad, and loop/bind through different shader effects, and so on ... Thanks all!
  9. i am reading this book : link in the OpenGL Rendering Pipeline section there is a picture like this: link but the question is this i dont really understand why it is necessary to turn pixel data in to fragment and then fragment into pixel could please give me a source or a clear Explanation that why it is necessary ? thank you so mu
  10. In order to increase the aesthetics, we looked for tips on the post-processing filter for our engine and came up with the idea of using a VHS / Analog post-processing filter, Because my teammate had already built OpenGL shaders in the past and that's kind of his hobby, he gave me the link to shadertoy. This site is amazing! There're a lot of shaders to use as a base we can build on, and it's also 100% web thanks to WebGL. This shader in particular caught my eye: It's really cool, and yet there are no VHS artifacts that can really obstruct the players' view . So I did a little tinkering with JMonkeyEngine and got this result: I'm really happy with the results. I could however reduce the blur amount: it can be annoying it it's too high...
  11. I'm using the OPENGL with eclipse+JOGL.My goal is to create movement of the camera and the player.I create main class, which create some box in 3D and hold an object of PlayerAxis.I create PlayerAxis class which hold the axis of the player.If we want to move the camera, then in the main class I call to the func "cameraMove"(from PlayerAxis) and it update the player axis.That's work good.The problem start if I move the camera on 2 axis, for example if I move with the camera right(that's on the y axis)and then down(on the x axis) -in some point the move front is not to the front anymore..In order to move to the front, I doplayer.playerMoving(0, 0, 1);And I learn that in order to keep the front move, I need to convert (0, 0, 1) to the player axis, and then add this.I think I dont do the convert right.. I will be glad for help!Here is part of my PlayerAxis class: //player coordinate float x[] = new float[3]; float y[] = new float[3]; float z[] = new float[3]; public PlayerAxis(float move_step, float angle_move) { x[0] = 1; y[1] = 1; z[2] = -1; step = move_step; angle = angle_move; setTransMatrix(); } public void cameraMoving(float angle_step, String axis) { float[] new_x = x; float[] new_y = y; float[] new_z = z; float alfa = angle_step * angle; switch(axis) { case "x": new_z = addVectors(multScalar(z, COS(alfa)), multScalar(y, SIN(alfa))); new_y = subVectors(multScalar(y, COS(alfa)), multScalar(z, SIN(alfa))); break; case "y": new_x = addVectors(multScalar(x, COS(alfa)), multScalar(z, SIN(alfa))); new_z = subVectors(multScalar(z, COS(alfa)), multScalar(x, SIN(alfa))); break; case "z": new_x = addVectors(multScalar(x, COS(alfa)), multScalar(y, SIN(alfa))); new_y = subVectors(multScalar(y, COS(alfa)), multScalar(x, SIN(alfa))); } x = new_x; y = new_y; z = new_z; normalization(); } public void playerMoving(float x_move, float y_move, float z_move) { float[] move = new float[3]; move[0] = x_move; move[1] = y_move; move[2] = z_move; setTransMatrix(); float[] trans_move = transVector(move); position[0] = position[0] + step*trans_move[0]; position[1] = position[1] + step*trans_move[1]; position[2] = position[2] + step*trans_move[2]; } public void setTransMatrix() { for (int i = 0; i < 3; i++) { coordiTrans[0][i] = x[i]; coordiTrans[1][i] = y[i]; coordiTrans[2][i] = z[i]; } } public float[] transVector(float[] v) { return multiplyMatrixInVector(coordiTrans, v); } and in the main class i have this: public void keyPressed(KeyEvent e) { if (e.getKeyCode()== KeyEvent.VK_ESCAPE) { System.exit(0); //player move } else if (e.getKeyCode()== KeyEvent.VK_W) { //front //moveAmount[2] += -0.1f; player.playerMoving(0, 0, 1); } else if (e.getKeyCode()== KeyEvent.VK_S) { //back //moveAmount[2] += 0.1f; player.playerMoving(0, 0, -1); } else if (e.getKeyCode()== KeyEvent.VK_A) { //left //moveAmount[0] += -0.1f; player.playerMoving(-1, 0, 0); } else if (e.getKeyCode()== KeyEvent.VK_D) { //right //moveAmount[0] += 0.1f; player.playerMoving(1, 0, 0); } else if (e.getKeyCode()== KeyEvent.VK_E) { //moveAmount[0] += 0.1f; player.playerMoving(0, 1, 0); } else if (e.getKeyCode()== KeyEvent.VK_Q) { //moveAmount[0] += 0.1f; player.playerMoving(0, -1, 0); //camera move } else if (e.getKeyCode()== KeyEvent.VK_I) { //up player.cameraMoving(1, "x"); } else if (e.getKeyCode()== KeyEvent.VK_K) { //down player.cameraMoving(-1, "x"); } else if (e.getKeyCode()== KeyEvent.VK_L) { //right player.cameraMoving(-1, "y"); } else if (e.getKeyCode()== KeyEvent.VK_J) { //left player.cameraMoving(1, "y"); } else if (e.getKeyCode()== KeyEvent.VK_O) { //right round player.cameraMoving(-1, "z"); } else if (e.getKeyCode()== KeyEvent.VK_U) { //left round player.cameraMoving(1, "z"); } } finallt found it.... i confused with the transformation matrix row and col. thanks anyway!
  12. So, i'm currently trying to implement an SSAO shader from THIS tutorial and i'm running into a few issues here. Now, this SSAO method requires view space positions and normals. I'm storing the normals in my deferred renderer in world-space so i had to do a conversion and reconstruct the position from the depth buffer. And something there goes horribly wrong (which has probably to do with worldspace to viewspace transformations). (here is the full shader source code if someone wants to take a look at it) Now, i suspect that the normals are the culprit. vec3 normal = ((uNormalViewMatrix*vec4(normalize(texture2D(sNormals, vTexcoord).rgb),1.0)).xyz); "sNormals" is a 2D texture which stores the normals in world space in a RGB FP16 buffer. Now i can't use the camera viewspace matrix to transform the normals into viewspace as the cameras position isn't set at (0,0,0), thus skewing the result. So what i did is to create a new viewmatrix specifically for this normal without the position at vec3(0,0,0); //"camera" is the camera which was used for rendering the normal buffer renderer.setUniform4m(ressources->shaderSSAO->getUniform("uNormalViewMatrix"), glmExt::createViewMatrix(glm::vec3(0,0,0),camera.getForward(),camera.getUp())//parameters are (position,forwardVector,upVector) ); Though i have the feeling this is the wrong approach. Is this right or is there a better/correct way of transforming a world space normal into viewspace?
  13. I'm having issues loading textures, as I'm clueless on how to handle / load images maybe I missing something, but the past few days I just google a lot to try to find a solution. Well theres two issues I think, one I'm using Kotlin Native (EAP) and OpenGL wrapper / STB image, so I'm not quite sure wheres the issue, if someone with more experience could give me some hints on how to solve this issue? The code is here, if I'm not mistaken the workflow is pretty straight forward, stbi_load returns the pixels of the image (as char array or byte array) and you need to pass those pixels directly to glTexImage2D, so a I'm missing something here it seems. Regards
  14. Hi, I'm trying mix two textures using own shader system, but I have a problem (I think) with uniforms. Code: https://github.com/HawkDeath/shader/tree/test To debug I use RenderDocs, but I did not receive good results. In the first attachment is my result, in the second attachment is what should be. PS. I base on this tutorial https://learnopengl.com/Getting-started/Textures.
  15. So, i stumbled upon the topic of gamma correction. https://learnopengl.com/Advanced-Lighting/Gamma-Correction So from what i've been able to gather: (Please correct me if i'm wrong) Old CRT monitors couldn't display color linearly, that's why gamma correction was nessecary. Modern LCD/LED monitors don't have this issue anymore but apply gamma correction anyway. (For compatibility reasons? Can this be disabled?) All games have to apply gamma correction? (unsure about that) All textures stored in file formats (.png for example) are essentially stored in SRGB color space (as what we see on the monitor is skewed due to gamma correction. So the pixel information is the same, the percieved colors are just wrong.) This makes textures loaded into the GL_RGB format non linear, thus all lighting calculations are wrong You have to always use the GL_SRGB format to gamma correct/linearise textures which are in SRGB format Now, i'm kinda confused how to proceed with applying gamma correction in OpenGL. First of, how can i check if my Monitor is applying gamma correction? I noticed in my monitor settings that my color format is set to "RGB" (can't modify it though.) I'm connected to my PC via a HDMI cable. I'm also using the full RGB range (0-255, not the 16 to ~240 range) What i tried to do is to apply a gamma correction shader shown in the tutorial above which looks essentially like this: (it's a postprocess shader which is applied at the end of the renderpipeline) vec3 gammaCorrection(vec3 color){ // gamma correction color = pow(color, vec3(1.0/2.2)); return color; } void main() { vec3 color; vec3 tex = texture2D(texture_diffuse, vTexcoord).rgb; color = gammaCorrection(tex); outputF = vec4(color,1.0f); } The results look like this: No gamma correction: With gamma correction: The colors in the gamma corrected image look really wased out. (To the point that it's damn ugly. As if someone overlayed a white half transparent texture. I want the colors to pop.) Do i have to change the textures from GL_RGB to GL_SRGB in order to gamma correct them in addition to applying the post process gamma correction shader? Do i have to do the same thing with all FBOs? Or is this washed out look the intended behaviour?
  16. Me again. I noticed a weird issue with color banding in my current PBR shader. After a bit of experimentation i noticed that the fresnel calculation seems to be the culprit. Here is how the colorbanding looks like (it's a bit dark, but noticeable): I also think that the fresnel calculation is a bit off. This is the actual shader (stripped everything away except the fresnel calculation:) It's worth noting that i'm writing those values into a 16 bit floating point buffer. (So the FBO precision shouldn't be the culprit.) Is this a math based precision error? (especially in the pow() function) Also another thing i noticed, The fresnel effect is supposed to look like this: (picture shamelessly stolen from google) However, no matter what i do i never get this effect in my shader. (I tried all lighting conditions and material values.) Here is what a material with 50% roughness and 50% metallic value looks like: I noticed that switching the "VdotH" dot product to "LdotV" makes this effect somewhat work, but i read conflicting information on the internet as if this is even correct. Here is the complete shader: Anyone has an idea why the banding effect takes place and if the fresnel calculation is even correct?
  17. This week Hello everyone! This week, as always, I fixed few bugs, did few tweaks and implemented small features. Here's a list of things I've done this week: Tweaked enemy prices and levels. Added object picking Added sounds and music Tweaked audio gains for different sounds and music Added capability of selling towers Added new cursor Implemented support for multiple enemy waves Added new enemy: Tank Added new turret type: Rocket turret Screenshots: Important decision Yesterday I came to important realization while making my game. I realized that I need to build a fully working prototype of the game, figure out all the mechanics, implement all the tower and enemy types first and only then continue doing the minor things and polishing things up. I also realized that I should spend less time on music and 3D models. All these things will be done, but not now. I need to make my game fun first, and only then worry about all the assets. I don't want to repeat same mistake which I did with my previous games where I spent too much time on graphics, sounds, performance optimizations and too little time for actual gameplay mechanics. Problems There's one problem which I currently face, and it has to do with the "Tesla Coil" tower. As of now it slows down the enemies in its range, but there's a problem with that. The problem arises when you put the tower at the very end of the maze. When you do that, it not only slows down the enemies in its range, but it also slows down any enemies which came before them. This is because of the obstacle avoidance which makes it so that the enemies couldn't go through each other like some sort of ghosts. The only solution which I can think of right now is to remove this type of tower and replace it with something else. Next week This coming week I'll start thinking of and implementing all the different tower and enemy types. I might do some very basic 3D models to use as placeholders as well. That's all for now, thanks for reading Twitter: https://twitter.com/extrabitgamesFacebook: https://www.facebook.com/extrabitgamesWebsite: http://extrabitgames.com
  18. Hi I am trying to program shadow volumes and i stumbled upon an artifact which i can not find the cause for. I generate the shadow volumes using a geometry shader with reversed extrusion (projecting the lightfacing triangles to infinity) and write the stencil buffer according to z-fail. The base of my code is the "lighting" chapter from learnopengl.com, where i extended the shader class to include geometry shader. I also modified the "lightingshader" to draw the ambient pass when "pass" is set to true and the diffuse/ specular pass when set to false. For easier testing i added a view controls to switch on/off the shadow volumes' color rendering or to change the cubes' position, i made the lightnumber controllable and changed the diffuse pass to render green for easier visualization of my problem. The first picture shows the rendered scene for one point light, all cubes and the front cube's shadow volume is the only one created (intentional). Here, all is rendered as it should be with all lit areas green and all areas inside the shadow volume black (with the volume's sides blended over). If i now turn on the shadow volumes for all the other cubes, we get a bit of a mess, but its also obvious that some areas that were in shadow before are now erroneously lit (for example the first cube to the right from the originaly shadow volumed cube). From my testing the areas erroneously lit are the ones where more than one shadow volume marks the area as shadowed. To check if a wrong stencil buffer value caused this problem i decided to change the stencil function for the diffuse pass to only render if the stencil is equal to 2. As i repeated this approach with different values for the stencil function i found out that if i set the value equal to 1 or any other uneven value the lit and shadowed areas are inverted and if i set it to 0 or any other even value i get the results shown above. This lead me to believe that the value and thus the stencil buffer values may be clamped to [0,1] which would also explain the artifact, because twice in shadow would equal in no shadow at all, but from what i found on the internet and from what i tested with GLint stencilSize = 0; glGetFramebufferAttachmentParameteriv(GL_DRAW_FRAMEBUFFER, GL_STENCIL, GL_FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE, &stencilSize); my stencilsize is 8 bit, which should be values within [0,255]. Does anyone know what might be the cause for this artifact or the confusing results with other stencil functions? // [the following code includes all used gl* functions, other parts are due to readability partialy excluded] // glfw: initialize and configure // ------------------------------ glfwInit(); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 4); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // glfw window creation // -------------------- GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL); if (window == NULL) { cout << "Failed to create GLFW window" << endl; glfwTerminate(); return -1; } glfwMakeContextCurrent(window); glfwSetFramebufferSizeCallback(window, framebuffer_size_callback); glfwSetCursorPosCallback(window, mouse_callback); glfwSetScrollCallback(window, scroll_callback); // tell GLFW to capture our mouse glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED); // glad: load all OpenGL function pointers // --------------------------------------- if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { cout << "Failed to initialize GLAD" << endl; return -1; } // ==================================================================================================== // window and functions are set up // ==================================================================================================== // configure global opengl state // ----------------------------- glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); // build and compile our shader program [...] // set up vertex data (and buffer(s)) and configure vertex attributes [...] // shader configuration [...] // render loop // =========== while (!glfwWindowShouldClose(window)) { // input processing and fps calculation[...] // render // ------ glClearColor(0.1f, 0.1f, 0.1f, 1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glDepthMask(GL_TRUE); //enable depth writing glDepthFunc(GL_LEQUAL); //avoid z-fighting //draw ambient component into color and depth buffer view = camera.GetViewMatrix(); projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f); // setting up lighting shader for ambient pass [...] // render the cubes glBindVertexArray(cubeVAO); for (unsigned int i = 0; i < 10; i++) { //position cube [...] glDrawArrays(GL_TRIANGLES, 0, 36); } //------------------------------------------------------------------------------------------------------------------------ glDepthMask(GL_FALSE); //disable depth writing glEnable(GL_BLEND); glBlendFunc(GL_ONE, GL_ONE); //additive blending glEnable(GL_STENCIL_TEST); //setting up shadowShader and lightingShader [...] for (int light = 0; light < lightsused; light++) { glDepthFunc(GL_LESS); glClear(GL_STENCIL_BUFFER_BIT); //configure stencil ops for front- and backface to write according to z-fail glStencilOpSeparate(GL_FRONT, GL_KEEP, GL_DECR_WRAP, GL_KEEP); //-1 for front-facing glStencilOpSeparate(GL_BACK, GL_KEEP, GL_INCR_WRAP, GL_KEEP); //+1 for back-facing glStencilFunc(GL_ALWAYS, 0, GL_TRUE); //stencil test always passes if(hidevolumes) glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE); //disable writing to the color buffer glDisable(GL_CULL_FACE); glEnable(GL_DEPTH_CLAMP); //necessary to render SVs into infinity //draw SV------------------- shadowShader.use(); shadowShader.setInt("lightnr", light); int nr; if (onecaster) nr = 1; else nr = 10; for (int i = 0; i < nr; i++) { //position cube[...] glDrawArrays(GL_TRIANGLES, 0, 36); } //-------------------------- glDisable(GL_DEPTH_CLAMP); glEnable(GL_CULL_FACE); glStencilFunc(GL_EQUAL, 0, GL_TRUE); //stencil test passes for ==0 so only for non shadowed areas glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP); //keep stencil values for illumination glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE); //enable writing to the color buffer glDepthFunc(GL_LEQUAL); //avoid z-fighting //draw diffuse and specular pass lightingShader.use(); lightingShader.setInt("lightnr", light); // render the cubes for (unsigned int i = 0; i < 10; i++) { //position cube[...] glDrawArrays(GL_TRIANGLES, 0, 36); } } glDisable(GL_BLEND); glDepthMask(GL_TRUE); //enable depth writing glDisable(GL_STENCIL_TEST); //------------------------------------------------------------------------------------------------------------------------ // also draw the lamp object(s) [...] // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.) // ------------------------------------------------------------------------------- glfwSwapBuffers(window); glfwP } // optional: de-allocate all resources once they've outlived their purpose: // ------------------------------------------------------------------------ glDeleteVertexArrays(1, &cubeVAO); glDeleteVertexArrays(1, &lightVAO); glDeleteBuffers(1, &VBO); // glfw: terminate, clearing all previously allocated GLFW resources. // ------------------------------------------------------------------ glfwTerminate(); return 0;
  19. Hi, i am self teaching me graphics and oo programming and came upon this: My Window class creates an input handler instance, the glfw user pointer is redirected to that object and methods there do the input handling for keyboard and mouse. That works. Now as part of the input handling i have an orbiting camera that is controlled by mouse movement. GLFW_CURSOR_DISABLED is set as proposed in the glfw manual. The manual says that in this case the cursor is automagically reset to the window's center. But if i don't reset it manually with glfwSetCursorPos( center ) mouse values seem to add up until the scene is locked up. Here are some code snippets, mostly standard from tutorials: // EventHandler m_eventHandler = new EventHandler( this, glm::vec3( 0.0f, 5.0f, 0.0f ), glm::vec3( 0.0f, 1.0f, 0.0f ) ); glfwSetWindowUserPointer( m_window, m_eventHandler ); m_eventHandler->setCallbacks(); Creation of the input handler during window creation. For now, the camera is part of the input handler, hence the two vectors (position, up-vector). In future i'll take that functionally out into an own class that inherits from the event handler. void EventHandler::setCallbacks() { glfwSetCursorPosCallback( m_window->getWindow(), cursorPosCallback ); glfwSetKeyCallback( m_window->getWindow(), keyCallback ); glfwSetScrollCallback( m_window->getWindow(), scrollCallback ); glfwSetMouseButtonCallback( m_window->getWindow(), mouseButtonCallback ); } Set callbacks in the input handler. // static void EventHandler::cursorPosCallback( GLFWwindow *w, double x, double y ) { EventHandler *c = reinterpret_cast<EventHandler *>( glfwGetWindowUserPointer( w ) ); c->onMouseMove( (float)x, (float)y ); } Example for the cursor pos callback redirection to a class method. // virtual void EventHandler::onMouseMove( float x, float y ) { if( x != 0 || y != 0 ) { // @todo cursor should be set automatically, according to doc if( m_window->isCursorDisabled() ) glfwSetCursorPos( m_window->getWindow(), m_center.x, m_center.y ); // switch up/down because its more intuitive m_yaw += m_mouseSensitivity * ( m_center.x - x ); m_pitch += m_mouseSensitivity * ( m_center.y - y ); // to avoid locking if( m_pitch > 89.0f ) m_pitch = 89.0f; if( m_pitch < -89.0f ) m_pitch = -89.0f; // Update Front, Right and Up Vectors updateCameraVectors(); } } // onMouseMove() Mouse movement processor method. The interesting part is the manual reset of the mouse position that made the thing work ... // straight line distance between the camera and look at point, here (0,0,0) float distance = glm::length( m_target - m_position ); // Calculate the camera position using the distance and angles float camX = distance * -std::sin( glm::radians( m_yaw ) ) * std::cos( glm::radians( m_pitch) ); float camY = distance * -std::sin( glm::radians( m_pitch) ); float camZ = -distance * std::cos( glm::radians( m_yaw ) ) * std::cos( glm::radians( m_pitch) ); // Set the camera position and perspective vectors m_position = glm::vec3( camX, camY, camZ ); m_front = glm::vec3( 0.0, 0.0, 0.0 ) - m_position; m_up = m_worldUp; m_right = glm::normalize( glm::cross( m_front, m_worldUp ) ); glm::lookAt( m_position, m_front, m_up ); Orbiting camera vectors calculation in updateCameraVectors(). Now, for my understanding, as the glfw manual explicitly states that if cursor is disabled then it is reset to the center, but my code only works if it is reset manually, i fear i am doing something wrong. It is not world moving (only if there is a world to render :-)), but somehow i am curious what i am missing. I am not a professional programmer, just a hobbyist, so it may well be that i got something principally wrong :-) And thanks for any hints and so ...
  20. Hi, currently I'm helping my friend with his master thesis creating 3d airplane simulation, which he will use as presentation {just part of the whole}. I've got Boening 737-800 model, which is read from obj file format and directly rendered using my simulator program. The model has many of moving parts, they move independently basing on defined balls. Here's left wing from the top to depict one element and its move logic: Each moving object {here it is aleiron_left} has two balls: _left and _right which define the horizontal line to rotate around. I created movement and rotate logic by just using translatef and rotatef, each object is moved independently within its own push and pop matrixes. Once the project runs I'm able to move the aleiron based on parameter I store in some variable, and it moves alright: First one is before move, and the second one after move. I added balls for direct reference with 3ds max model. The balls are also moved using translatef and rotatef using the same move logic, so they are "glued" to their parent part. Problem is, I need to calculate their world coordinates after move, so in the next step out of the render method I need to obtain direct x,y,z coordinates without again using translatef and rotatef. I tried to multiply some matrixes and so on, but without result and currently I've got no idea how to do that.. Fragment of code looks like this: void DrawModel(Model.IModel model) { GL.glLoadIdentity(); GL.glPushMatrix(); this.SetSceneByCamera(); foreach (Model.IModelPart part in model.ModelParts) this.DrawPart(part); GL.glPopMatrix(); } void DrawPart(Model.IModelPart part) { bool draw = true; GL.glPushMatrix(); #region get part children Model.IModelPart child_top = part.GetChild("_top"); Model.IModelPart child_left = part.GetChild("_left"); Model.IModelPart child_right = part.GetChild("_right"); Model.IModelPart child_bottom = part.GetChild("_bottom"); #endregion get part children #region by part switch (part.PartTBase) { case Model.ModelPart.PartTypeBase.ALEIRON: { #region aleiron float moveBy = 0.0f; bool selected = false; switch (part.PartT) { case Model.ModelPart.PartType.ALEIRON_L: { selected = true; moveBy = this.GetFromValDic(part); moveBy *= -1; } break; } if (selected && child_left != null && child_right != null) { GL.glTranslatef(child_right.GetCentralPoint.X, child_right.GetCentralPoint.Y, child_right.GetCentralPoint.Z); GL.glRotatef(moveBy, child_left.GetCentralPoint.X - child_right.GetCentralPoint.X, child_left.GetCentralPoint.Y - child_right.GetCentralPoint.Y, child_left.GetCentralPoint.Z - child_right.GetCentralPoint.Z); GL.glTranslatef(-child_right.GetCentralPoint.X, -child_right.GetCentralPoint.Y, -child_right.GetCentralPoint.Z); } #endregion aleiron } break; } #endregion by part #region draw part if (!part.Visible) draw = false; if (draw) { GL.glBegin(GL.GL_TRIANGLES); for (int i = 0; i < part.ModelPoints.Count; i += 3) { if (part.ModelPoints[i].GetTexCoord != null) GL.glTexCoord3d((double)part.ModelPoints[i].GetTexCoord.X, (double)part.ModelPoints[i].GetTexCoord.Y, (double)part.ModelPoints[i].GetTexCoord.Z); GL.glVertex3f(part.ModelPoints[i].GetPoint.X, part.ModelPoints[i].GetPoint.Y, part.ModelPoints[i].GetPoint.Z); if (part.ModelPoints[i + 1].GetTexCoord != null) GL.glTexCoord3d((double)part.ModelPoints[i + 1].GetTexCoord.X, (double)part.ModelPoints[i + 1].GetTexCoord.Y, (double)part.ModelPoints[i + 1].GetTexCoord.Z); GL.glVertex3f(part.ModelPoints[i + 1].GetPoint.X, part.ModelPoints[i + 1].GetPoint.Y, part.ModelPoints[i + 1].GetPoint.Z); if (part.ModelPoints[i + 2].GetTexCoord != null) GL.glTexCoord3d((double)part.ModelPoints[i + 2].GetTexCoord.X, (double)part.ModelPoints[i + 2].GetTexCoord.Y, (double)part.ModelPoints[i + 2].GetTexCoord.Z); GL.glVertex3f(part.ModelPoints[i + 2].GetPoint.X, part.ModelPoints[i + 2].GetPoint.Y, part.ModelPoints[i + 2].GetPoint.Z); } GL.glEnd(); } #endregion draw part GL.glPopMatrix(); } What happens step by step: Prepare scene, set the model camera by current variables {user can move camera using keyboard and mouse in all directions}. Take model which contains all modelParts within and draw them one by one. Each part has its own type and subtype set by part name. Draw current part independently, get its child_left and child_right -> those are the balls by name. Get moveBy value which is angle. Every part has its own variable which is modified using keyboard like "press a, increase variable x for 5.0f", which in turn will rotate aleiron up by 5.0f. Move and rotate object by its children Draw part triangles {the part has its own list of triangles that are read from obj file} When I compute the blue ball that is glued to its parent, I do exactly the same so it moves with the same manner: case Model.ModelPart.PartTypeBase.FLOW: { float moveBy = 0.0f; Model.IModelPart parent = part.GetParent(); if (parent != null) { moveBy = this.GetFromValDic(parent); if (parent.Reverse) moveBy *= -1.0f; child_left = parent.GetChild("_left"); child_right = parent.GetChild("_right"); } if (child_left != null && child_right != null) { GL.glGetFloatv(GL.GL_MODELVIEW_MATRIX, part.BeforeMove); GL.glTranslatef(child_right.GetCentralPoint.X, child_right.GetCentralPoint.Y, child_right.GetCentralPoint.Z); GL.glRotatef(moveBy, child_left.GetCentralPoint.X - child_right.GetCentralPoint.X, child_left.GetCentralPoint.Y - child_right.GetCentralPoint.Y, child_left.GetCentralPoint.Z - child_right.GetCentralPoint.Z); GL.glTranslatef(-child_right.GetCentralPoint.X, -child_right.GetCentralPoint.Y, -child_right.GetCentralPoint.Z); } } break; Before move I read the model matrix using GL.glGetFloatv(GL.GL_MODEL_MATRIX, matrix), which gives me those values {red contains current model camera}: The blue ball has its own initial central point computed, and currently it is (x, y, z): 339.6048, 15.811758, -166.209473. As far as I'm concerned, the point world coordinates never change, only its matrix is moved and rotated around some point. So the final question is, how to calculate the same point world coordinates after the object is moved and rotated? PS: to visualize the problem, I've created new small box, which I placed on the center of the blue ball after it is moved upwards. The position of the box is written by eye - I just placed it couple of times and after x try, I managed to place it correctly using similar world coordinates: First one is from the left of the box, and the second one is from behind. The box world coordinates are (x, y, z): 340.745117f, 30.0f, -157.6322f, so according to original central point of blue ball it is a bit higher and closer to the center of the wing. Simply put, I need to: take original central point of blue ball: 339.6048, 15.811758, -166.209473 after the movement and rotation of the blue ball is finished, apply some algorithm {like take something from modelview_matrix, multiply by something other} finally, after the algorithm is complete, in result I get 340.745117f, 30.0f, -157.6322f point {but now computed}, which is the central point in world matrix after movement. PS2: Sorry for long post, I tried to exactly explain what I'm dealing with. Thank you in advance for your help.
  21. Hello fellow programmers, For a couple of days now i've decided to build my own planet renderer just to see how floating point precision issues can be tackled. As you probably imagine, i've quickly faced FPP issues when trying to render absurdly large planets. I have used the classical quadtree LOD approach; I've generated my grids with 33 vertices, (x: -1 to 1, y: -1 to 1, z = 0). Each grid is managed by a TerrainNode class that, depending on the side it represents (top, bottom, left right, front, back), creates a special rotation-translation matrix that moves and rotates the grid away from the origin so that when i finally normalize all the vertices on my vertex shader i can get a perfect sphere. T = glm::translate(glm::dmat4(1.0), glm::dvec3(0.0, 0.0, 1.0)); R = glm::rotate(glm::dmat4(1.0), glm::radians(180.0), glm::dvec3(1.0, 0.0, 0.0)); sides[0] = new TerrainNode(1.0, radius, T * R, glm::dvec2(0.0, 0.0), new TerrainTile(1.0, SIDE_FRONT)); T = glm::translate(glm::dmat4(1.0), glm::dvec3(0.0, 0.0, -1.0)); R = glm::rotate(glm::dmat4(1.0), glm::radians(0.0), glm::dvec3(1.0, 0.0, 0.0)); sides[1] = new TerrainNode(1.0, radius, R * T, glm::dvec2(0.0, 0.0), new TerrainTile(1.0, SIDE_BACK)); // So on and so forth for the rest of the sides As you can see, for the front side grid, i rotate it 180 degrees to make it face the camera and push it towards the eye; the back side is handled almost the same way only that i don't need to rotate it but simply push it away from the eye. The same technique is applied for the rest of the faces (obviously, with the proper rotations / translations). The matrix that result from the multiplication of R and T (in that particular order) is send to my vertex shader as `r_Grid'. // spherify vec3 V = normalize((r_Grid * vec4(r_Vertex, 1.0)).xyz); gl_Position = r_ModelViewProjection * vec4(V, 1.0); The `r_ModelViewProjection' matrix is generated on the CPU in this manner. // No the most efficient way, but it works. glm::dmat4 Camera::getMatrix() { // Create the view matrix // Roll, Yaw and Pitch are all quaternions. glm::dmat4 View = glm::toMat4(Roll) * glm::toMat4(Pitch) * glm::toMat4(Yaw); // The model matrix is generated by translating in the oposite direction of the camera. glm::dmat4 Model = glm::translate(glm::dmat4(1.0), -Position); // Projection = glm::perspective(fovY, aspect, zNear, zFar); // zNear = 0.1, zFar = 1.0995116e12 return Projection * View * Model; } I managed to get rid of z-fighting by using a technique called Logarithmic Depth Buffer described in this article; it works amazingly well, no z-fighting at all, at least not visible. Each frame i'm rendering each node by sending the generated matrices this way. // set the r_ModelViewProjection uniform // Sneak in the mRadiusMatrix which is a matrix that contains the radius of my planet. Shader::setUniform(0, Camera::getInstance()->getMatrix() * mRadiusMatrix); // set the r_Grid matrix uniform i created earlier. Shader::setUniform(1, r_Grid); grid->render(); My planet's radius is around 6400000.0 units, absurdly large, but that's what i really want to achieve; Everything works well, the node's split and merge as you'd expect, however whenever i get close to the surface of the planet the rounding errors start to kick in giving me that lovely stairs effect. I've read that if i could render each grid relative to the camera i could get better precision on the surface, effectively getting rid of those rounding errors. My question is how can i achieve this relative to camera rendering in my scenario here? I know that i have to do most of the work on the CPU with double, and that's exactly what i'm doing. I only use double on the CPU side where i also do most of the matrix multiplications. As you can see from my vertex shader i only do the usual r_ModelViewProjection * (some vertex coords). Thank you for your suggestions!
  22. Hello again, everyone! Today is going to be a very short blog entry because all I wanted to show you is the new soundtracks which I created. As of now I only have 2 soundtracks, but I plan on making total of 12, or at least 10. The genre I choose is psychedelic trance. The main reason for it is because it's fast paced and I think it would suit my game pretty well. I also added shooting and exploding sounds which make the game just a bit more interesting. You can have a listen of the soundtracks here: That's all for today, thanks for reading! Twitter: https://twitter.com/extrabitgames Facebook: https://www.facebook.com/extrabitgames Website: http://extrabitgames.com
  23. Subscribe to our subreddit to get all the updates from the team! Recently I've been tackling with more organic low poly terrains. The default way of creating indices for a 3D geometry is the following (credits) : A way to create simple differences that makes the geometry slightly more complicated and thus more organic is to vertically swap the indices of each adjacent quad. In other words, each adjacent quad to a centered quad is its vertical mirror. Finally, by not sharing the vertices and hence by creating two triangles per quad, this is the result with a coherent noise generator (joise) : It is called flat shading.
  24. Good day, everyone! This week I've been working on various small fixes, improvements and features. Here's an incomplete list of all the things I've done: As you can see there are quite a few commits related to performance improvements such as added frustum culling, improved memory usage, pathfinding improvements and so on. The one main thing that's missing from this list is the addition of the new tower type which for now I just call "the slower" which as the name suggests, slows down the enemies. If any of you have played the original Red Alert you might notice that for this particular tower I took inspiration from the so called Tesla Coil. The only difference is that instead of electrocuting it's enemies, it just slows them down. Here's how it looks in Blender: And in game: Also, for the above image you can see how the UI looks. It's still very primitive and will be changed later on, but for now it does the trick. It lets to select a tower and tell the game when you are ready for the level to begin. Another thing which I've been working on was music. The funny thing is the genre which I chose. It's psytrance I thought that the fast tempo and monotonic bassline would be suitable for this type of game. After all, it is KIND of an action game. And the way I see it, when it's finished, there will be lots of explosions going on. Anyways, as mentioned in the list above, I also implemented placeholder main and options menus along with splash screen. This is how the menus look now (keep in mind they will be changed later on): Yes, very simple, I know. But they get the job done and it's still very early in development. One more thing which I added is money. You can now purchase towers and you will get money for each killed enemy. For now there's not functionality for selling the towers but it will be added soon. So that's all for this week. And for the next week, I think I will be doing 3D modelling and will be implementing new tower types along with other minor features. Twitter: https://twitter.com/extrabitgames Facebook: https://www.facebook.com/extrabitgames Website: http://extrabitgames.com
  25. thecheeselover

    Marching cubes

    Subscribe to our subreddit to get all the updates from the team! I have had difficulties recently with the Marching Cubes algorithm, mainly because the principal source of information on the subject was kinda vague and incomplete to me. I need a lot of precision to understand something complicated Anyhow, after a lot of struggles, I have been able to code in Java a less hardcoded program than the given source because who doesn't like the cuteness of Java compared to the mean looking C++? Oh and by hardcoding, I mean something like this : cubeindex = 0; if (grid.val[0] < isolevel) cubeindex |= 1; if (grid.val[1] < isolevel) cubeindex |= 2; if (grid.val[2] < isolevel) cubeindex |= 4; if (grid.val[3] < isolevel) cubeindex |= 8; if (grid.val[4] < isolevel) cubeindex |= 16; if (grid.val[5] < isolevel) cubeindex |= 32; if (grid.val[6] < isolevel) cubeindex |= 64; if (grid.val[7] < isolevel) cubeindex |= 128; By no mean I am saying that my code is better or more performant. It's actually ugly. However, I absolutely loathe hardcoding. Here's the result with a scalar field generated using the coherent noise library joise :
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