Sign in to follow this  
Owenx92

OpenGL WorldViewProj?

Recommended Posts

Owenx92    100
Hello,
First, sorry for my bad English..

I have question about GLSL,
I have a HLSL shader, In this shader, I use a World and a WorldViewProj matrices.
In DirectX, I can easily get these Matrices with this codes;

World:

D3DXMatrixIdentity(&[b]World[/b]);

View:
D3DXMatrixLookAtLH(&[b]View[/b], &Position, &Target, &Up);

Proj:
D3DXMatrixPerspectiveFovLH( &[b]Proj[/b], D3DX_PI /4, ScreenWidth / ScreenHeight, 1.0f, 1000.0f );

WorldViewProj:
[b]World [/b]*[b] View [/b]*[b] Proj[/b]

I've converted my HLSL shader to GLSL with "HLSL2GLSL" tool.
My shader compiles with no errors. But I need this matrices to use my shader..
And I don't know how to get these Matrices in OpenGL.. [img]http://public.gamedev.net/public/style_emoticons/default/sad.gif[/img]

I've searched but I couldn't find a solution.
Can anyone tell me how can I get these matrices in OpenGL?

Share this post


Link to post
Share on other sites
Geri    367
[color="#FF0000"] D3DXMatrixIdentity(&[b]World[/b]);[/color] --> [color="#2E8B57"]glLoadIdentity(....[/color]

[color="#FF0000"]D3DXMatrixLookAtLH(&[b]View[/b], &Position, &Target, &Up);[/color] --> [color="#2E8B57"]gluLookAt(...

[/color][color="#FF0000"]D3DXMatrixPerspectiveFovLH[/color] -->[color="#2E8B57"]gluPerspective(....

[/color][color="#FF0000"][b]World [/b]*[b] View [/b]*[b] Proj[/b][/color] --> [color="#2E8B57"][b]MODELVIEW [/b]*[b] PROJECTION[/b][/color]

Share this post


Link to post
Share on other sites
NumberXaero    2624
Depends on the opengl version. Older versions of opengl provided them as built in uniforms, in the newer versions of opengl you have to calculate them yourself and pass them to the shader. Most math libs built with graphics in mind should have calls to calculate them.

Share this post


Link to post
Share on other sites
Owenx92    100
[quote name='V-man' timestamp='1306196354' post='4814818']
See my link. Look for functions like glhLoadIdentityf2.
Build your matrix and upload to your shader.
[/quote]


I think this library is for Windows, but i'm using Linux :(

------

I have some matrices in GLSL shader..
For example:
gl_ModelViewProjectionMatrix
gl_ModelViewMatrix
gl_Vertex

What is ModelView Matrix?? is that same with ViewMatrix in DX?
Ok, I think gl_ModelViewProjectionMatrix is WorldViewProj matrix, is it right?

But how can I get the World matrix?

A part of my Shader is like this.. very simple..

---------------------------------------------------------------------------------------------------------------
uniform vec4 LightColor;
uniform vec4 LightPosition;
uniform vec4 MatColor;
uniform mat4 [b]World[/b];
uniform mat4 [b]WorldViewProjection[/b];


void VS( in A2V IN, out V2P OUT ) {

OUT.Pos = [b][color="#ff0000"]I NEED HELP HERE..[/color][/b] (in DX, it is [b]mul(IN.Position, WorldViewProj); [/b])
OUT.WorldPos = [color="#ff0000"][b]I NEED HELP HERE TOO..[/b][/color] (in DX it is [b]mul(IN.Position, World);[/b] )
OUT.LightDir = vec3( (LightPosition - OUT.WorldPos));
OUT.WorldNormal = normalize( ( IN.Normal * xlat_lib_constructMat3( World) ) );
OUT.Diffuse = (MatColor * LightColor);
OUT.TexCoord0 = IN.Tex0;
}
---------------------------------------------------------------------------------------------------------------

Share this post


Link to post
Share on other sites
jyk    2094
Regarding the terminology, with the fixed-function pipeline, the 'world' matrix in D3D corresponds to the 'model' matrix in OpenGL, so:

D3D: world->view->projection
OpenGL: model->view->projection

Furthermore, OpenGL collapses the model and view matrices into a single 'modelview' matrix, whereas D3D keeps the world and view matrices separate, so:

D3D: world->view->projection
OpenGL: modelview->projection

With modern shader code, all of this disappears and you just construct and use whatever matrices you need. Typically there'll still be 'model', 'view', and 'projection' transforms in one form or another, but which ones you upload and what you do with them exactly is up to you. (That said, the simplest possible vertex program will typically transform all incoming geometry by a single matrix that represents a concatenation of the model/world, camera/view, and projection transforms.)

Share this post


Link to post
Share on other sites
Owenx92    100
Ok, Its working [img]http://public.gamedev.net/public/style_emoticons/default/smile.gif[/img]

I used so, and I don't need Model Matrix anymore [img]http://public.gamedev.net/public/style_emoticons/default/smile.gif[/img]
-------------------------------

OUT.Pos = gl_ModelViewProjectionMatrix * gl_Vertex;
OUT.WorldPos = gl_ModelViewMatrix * gl_Vertex;
OUT.LightDir = LightPosition - OUT.WorldPos;
OUT.WorldNormal = normalize(gl_NormalMatrix * gl_Normal);
OUT.Diffuse = LightColor;
OUT.TexCoord0 = IN.Tex0;
-------------------------------

Thanks guys..

Share this post


Link to post
Share on other sites
V-man    813
The only problem with that is that you are using built in variables. Why don't you use a math library instead?
From http://opengl.org/wiki/Related_toolkits_and_APIs, there is the GLM library that is available for *nix. It is object orientated (compared to mine which is a C library). I don't like the OO approach but have a look. There are a lot of others too if you look at the big list at http://www.gamedev.net/topic/339189-unofficial-alternative-game-libraries-faq-updated-20308/

Share this post


Link to post
Share on other sites
jyk    2094
@The OP: You can find another list of game math libraries [url="http://www.ebonyfortress.co.uk/blog/free-game-development-libraries/#maths"]here[/url].

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Similar Content

    • By Kjell Andersson
      I'm trying to get some legacy OpenGL code to run with a shader pipeline,
      The legacy code uses glVertexPointer(), glColorPointer(), glNormalPointer() and glTexCoordPointer() to supply the vertex information.
      I know that it should be using setVertexAttribPointer() etc to clearly define the layout but that is not an option right now since the legacy code can't be modified to that extent.
      I've got a version 330 vertex shader to somewhat work:
      #version 330 uniform mat4 osg_ModelViewProjectionMatrix; uniform mat4 osg_ModelViewMatrix; layout(location = 0) in vec4 Vertex; layout(location = 2) in vec4 Normal; // Velocity layout(location = 3) in vec3 TexCoord; // TODO: is this the right layout location? out VertexData { vec4 color; vec3 velocity; float size; } VertexOut; void main(void) { vec4 p0 = Vertex; vec4 p1 = Vertex + vec4(Normal.x, Normal.y, Normal.z, 0.0f); vec3 velocity = (osg_ModelViewProjectionMatrix * p1 - osg_ModelViewProjectionMatrix * p0).xyz; VertexOut.velocity = velocity; VertexOut.size = TexCoord.y; gl_Position = osg_ModelViewMatrix * Vertex; } What works is the Vertex and Normal information that the legacy C++ OpenGL code seem to provide in layout location 0 and 2. This is fine.
      What I'm not getting to work is the TexCoord information that is supplied by a glTexCoordPointer() call in C++.
      Question:
      What layout location is the old standard pipeline using for glTexCoordPointer()? Or is this undefined?
       
      Side note: I'm trying to get an OpenSceneGraph 3.4.0 particle system to use custom vertex, geometry and fragment shaders for rendering the particles.
    • By markshaw001
      Hi i am new to this forum  i wanted to ask for help from all of you i want to generate real time terrain using a 32 bit heightmap i am good at c++ and have started learning Opengl as i am very interested in making landscapes in opengl i have looked around the internet for help about this topic but i am not getting the hang of the concepts and what they are doing can some here suggests me some good resources for making terrain engine please for example like tutorials,books etc so that i can understand the whole concept of terrain generation.
       
    • By KarimIO
      Hey guys. I'm trying to get my application to work on my Nvidia GTX 970 desktop. It currently works on my Intel HD 3000 laptop, but on the desktop, every bind textures specifically from framebuffers, I get half a second of lag. This is done 4 times as I have three RGBA textures and one depth 32F buffer. I tried to use debugging software for the first time - RenderDoc only shows SwapBuffers() and no OGL calls, while Nvidia Nsight crashes upon execution, so neither are helpful. Without binding it runs regularly. This does not happen with non-framebuffer binds.
      GLFramebuffer::GLFramebuffer(FramebufferCreateInfo createInfo) { glGenFramebuffers(1, &fbo); glBindFramebuffer(GL_FRAMEBUFFER, fbo); textures = new GLuint[createInfo.numColorTargets]; glGenTextures(createInfo.numColorTargets, textures); GLenum *DrawBuffers = new GLenum[createInfo.numColorTargets]; for (uint32_t i = 0; i < createInfo.numColorTargets; i++) { glBindTexture(GL_TEXTURE_2D, textures[i]); GLint internalFormat; GLenum format; TranslateFormats(createInfo.colorFormats[i], format, internalFormat); // returns GL_RGBA and GL_RGBA glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, createInfo.width, createInfo.height, 0, format, GL_FLOAT, 0); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); DrawBuffers[i] = GL_COLOR_ATTACHMENT0 + i; glBindTexture(GL_TEXTURE_2D, 0); glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, textures[i], 0); } if (createInfo.depthFormat != FORMAT_DEPTH_NONE) { GLenum depthFormat; switch (createInfo.depthFormat) { case FORMAT_DEPTH_16: depthFormat = GL_DEPTH_COMPONENT16; break; case FORMAT_DEPTH_24: depthFormat = GL_DEPTH_COMPONENT24; break; case FORMAT_DEPTH_32: depthFormat = GL_DEPTH_COMPONENT32; break; case FORMAT_DEPTH_24_STENCIL_8: depthFormat = GL_DEPTH24_STENCIL8; break; case FORMAT_DEPTH_32_STENCIL_8: depthFormat = GL_DEPTH32F_STENCIL8; break; } glGenTextures(1, &depthrenderbuffer); glBindTexture(GL_TEXTURE_2D, depthrenderbuffer); glTexImage2D(GL_TEXTURE_2D, 0, depthFormat, createInfo.width, createInfo.height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glBindTexture(GL_TEXTURE_2D, 0); glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depthrenderbuffer, 0); } if (createInfo.numColorTargets > 0) glDrawBuffers(createInfo.numColorTargets, DrawBuffers); else glDrawBuffer(GL_NONE); if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) std::cout << "Framebuffer Incomplete\n"; glBindFramebuffer(GL_FRAMEBUFFER, 0); width = createInfo.width; height = createInfo.height; } // ... // FBO Creation FramebufferCreateInfo gbufferCI; gbufferCI.colorFormats = gbufferCFs.data(); gbufferCI.depthFormat = FORMAT_DEPTH_32; gbufferCI.numColorTargets = gbufferCFs.size(); gbufferCI.width = engine.settings.resolutionX; gbufferCI.height = engine.settings.resolutionY; gbufferCI.renderPass = nullptr; gbuffer = graphicsWrapper->CreateFramebuffer(gbufferCI); // Bind glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo); // Draw here... // Bind to textures glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, textures[0]); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, textures[1]); glActiveTexture(GL_TEXTURE2); glBindTexture(GL_TEXTURE_2D, textures[2]); glActiveTexture(GL_TEXTURE3); glBindTexture(GL_TEXTURE_2D, depthrenderbuffer); Here is an extract of my code. I can't think of anything else to include. I've really been butting my head into a wall trying to think of a reason but I can think of none and all my research yields nothing. Thanks in advance!
    • By Adrianensis
      Hi everyone, I've shared my 2D Game Engine source code. It's the result of 4 years working on it (and I still continue improving features ) and I want to share with the community. You can see some videos on youtube and some demo gifs on my twitter account.
      This Engine has been developed as End-of-Degree Project and it is coded in Javascript, WebGL and GLSL. The engine is written from scratch.
      This is not a professional engine but it's for learning purposes, so anyone can review the code an learn basis about graphics, physics or game engine architecture. Source code on this GitHub repository.
      I'm available for a good conversation about Game Engine / Graphics Programming
    • By C0dR
      I would like to introduce the first version of my physically based camera rendering library, written in C++, called PhysiCam.
      Physicam is an open source OpenGL C++ library, which provides physically based camera rendering and parameters. It is based on OpenGL and designed to be used as either static library or dynamic library and can be integrated in existing applications.
       
      The following features are implemented:
      Physically based sensor and focal length calculation Autoexposure Manual exposure Lense distortion Bloom (influenced by ISO, Shutter Speed, Sensor type etc.) Bokeh (influenced by Aperture, Sensor type and focal length) Tonemapping  
      You can find the repository at https://github.com/0x2A/physicam
       
      I would be happy about feedback, suggestions or contributions.

  • Popular Now