Sign in to follow this  

OpenGL Quality of a sprite based game

This topic is 1841 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hey guys. I'm almost done writing a framework for a game. Making a 2D game, I've read some material on the web and realized two options I have are making it sprite based or doing it in 2D projection in OpenGL, since I'm targeting windows, android and iOS. I've decided to go with sprites for the initial version but I'm a bit worried of the graphics quality that can be achieved with sprites. I'm sure there are nice examples of sprite games that look awesome, but there's a buzz in my mind about it. "Sure you can achieve awesome looks with sprites" you would say, but my definition of awesome might differ from yours. I picked sprites over OpenGL because of animation simplicity and actually simplicity overall. I want to start small and not get caught in something I can't get out of, since I'm doing the whole game myself. So... What should I expect from sprites regarding quality(looks)?

 

Mercurial

Share this post


Link to post
Share on other sites

A: Yes it can look good, and second, B: what exactly are you trying to make? and C: what other alternative are you thinking about? I'm asking so we can compare for your particular situation,

 

The quality depends, of course, on drawing skills. But also about the chosen style and consistency of the graphical content. When chosing sprites, don't expect to make photo-realistic graphics. For cartoonish graphics though, it can work out really well. In facts, making your world, characters and animations look cartoonish, is easier to achieve with sprites. Because the shapes are more curvy / organic compared with polygon objects, and you have more freedom with the animations. Not that its impossible to do with 3D, but that requires high skills.

 

Speaking of skills, when chosing 3D, the overall difficulty to make things look *good* is higher. So unless you have plenty of time to create a "next-gen" engine + the artists that can make the content, a 3D engine will quickly look outdated when people compare it to Crysis, Unreal, or whatever we got. This is less of a problem when going for 2D. At least... if you can pick a specific, consistent style. And since you also aim for mobile devices, you can't make too complex 3D stuff anyway.

 

 

As for the technical aspect to make things look good, consider lighting as one of the most important factors. In 3D, there are a lot of options to simulate somewhat realistic lighting. Shadowmaps, geometric shapes, normal/specular mapping, (baked) GI, and so on. With sprites, this is a bit harder to achieve because your scene is literally flat, and thus lacking information you would need for proper lighting. Although a cartoonish style may not need realistic "correct" lighting, you still may need some tricks to get it look cool instead of flat and dull.

 

This is probably the reason why platform games are often semi-3D. Using a mixture of 3D shapes and sprites. Don't forget you can still use OpenGL for a 2D looking game. But as said, making a 3D engine requires more work in general. So if you don't really need it...

 

Greets,

Rick

Share this post


Link to post
Share on other sites

There are games out there that have very high definition sprites, take a look at the sprites from Skullgirls and Shank for example.

 

http://download.xbox.com/content/images/66acd000-77fe-1000-9115-d802584111db/1033/screenlg5.jpg

 

or

 

http://www.2d-x.com/wp-content/uploads/2010/03/Shank-2010-03-03-16-49-14-29.png

 

Both games use 2D sprites

Share this post


Link to post
Share on other sites

@Rick: Hey there. Well, alternatives I was considering was OpenGL and just making a 2D projection from above. It's a tower defense game. Indeed it should have a cartoonish look, not realistic.

 

@6B!: Those two look awesome! But as Rick said, it depends on drawing skills alot.

Share this post


Link to post
Share on other sites

A Tower Defense game. I would just make it 2D. Because you will likely reach your goal faster (= making the game), it likely runs better on mobile devices, and most important, drawing topview walking characters or towers likely looks better than using (low poly) 3D models. Just compare old RTS games (Command & Conquer, ...). I found the drawed sprite ones look better than their 3D counterparts. Because sprites can show any complex drawing, while with low-poly models, you are stuck to more simplistic shapes. Same with lighting & animations.

 

I don't know what you are using right now, but OpenGL can draw transparent quads (sprites) just as well. Neither are you forced to use all kinds of complex shaders or lights. In other words, with OpenGL, you can do what any 2D engine can do as well. So if you like the way how GL works, you can still decide to go for GL of course. And since GL works on those mobile devices as well, its not such a crazy choice. 

Share this post


Link to post
Share on other sites

Yeah I've worked with OpenGL ES on an iOS project at work, actually. So I would make a quad, apply sprite texture, and perhaps do post effects using shaders?

 

I'm using SFML at the moment. It's more of a make a game and learn than anything else. I've tried to detach all the drawing code from game code, so If i choose to change the graphics engine, I just have to write implementations for drawing classes etc.

 

I will probably stick with sprites, just would like to consider other options.

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Similar Content

    • By xhcao
      Does sync be needed to read texture content after access texture image in compute shader?
      My simple code is as below,
      glUseProgram(program.get());
      glBindImageTexture(0, texture[0], 0, GL_FALSE, 3, GL_READ_ONLY, GL_R32UI);
      glBindImageTexture(1, texture[1], 0, GL_FALSE, 4, GL_WRITE_ONLY, GL_R32UI);
      glDispatchCompute(1, 1, 1);
      // Does sync be needed here?
      glUseProgram(0);
      glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer);
      glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                                     GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, texture[1], 0);
      glReadPixels(0, 0, kWidth, kHeight, GL_RED_INTEGER, GL_UNSIGNED_INT, outputValues);
       
      Compute shader is very simple, imageLoad content from texture[0], and imageStore content to texture[1]. Does need to sync after dispatchCompute?
    • By Jonathan2006
      My question: is it possible to transform multiple angular velocities so that they can be reinserted as one? My research is below:
      // This works quat quaternion1 = GEQuaternionFromAngleRadians(angleRadiansVector1); quat quaternion2 = GEMultiplyQuaternions(quaternion1, GEQuaternionFromAngleRadians(angleRadiansVector2)); quat quaternion3 = GEMultiplyQuaternions(quaternion2, GEQuaternionFromAngleRadians(angleRadiansVector3)); glMultMatrixf(GEMat4FromQuaternion(quaternion3).array); // The first two work fine but not the third. Why? quat quaternion1 = GEQuaternionFromAngleRadians(angleRadiansVector1); vec3 vector1 = GETransformQuaternionAndVector(quaternion1, angularVelocity1); quat quaternion2 = GEQuaternionFromAngleRadians(angleRadiansVector2); vec3 vector2 = GETransformQuaternionAndVector(quaternion2, angularVelocity2); // This doesn't work //quat quaternion3 = GEQuaternionFromAngleRadians(angleRadiansVector3); //vec3 vector3 = GETransformQuaternionAndVector(quaternion3, angularVelocity3); vec3 angleVelocity = GEAddVectors(vector1, vector2); // Does not work: vec3 angleVelocity = GEAddVectors(vector1, GEAddVectors(vector2, vector3)); static vec3 angleRadiansVector; vec3 angularAcceleration = GESetVector(0.0, 0.0, 0.0); // Sending it through one angular velocity later in my motion engine angleVelocity = GEAddVectors(angleVelocity, GEMultiplyVectorAndScalar(angularAcceleration, timeStep)); angleRadiansVector = GEAddVectors(angleRadiansVector, GEMultiplyVectorAndScalar(angleVelocity, timeStep)); glMultMatrixf(GEMat4FromEulerAngle(angleRadiansVector).array); Also how do I combine multiple angularAcceleration variables? Is there an easier way to transform the angular values?
    • By dpadam450
      I have this code below in both my vertex and fragment shader, however when I request glGetUniformLocation("Lights[0].diffuse") or "Lights[0].attenuation", it returns -1. It will only give me a valid uniform location if I actually use the diffuse/attenuation variables in the VERTEX shader. Because I use position in the vertex shader, it always returns a valid uniform location. I've read that I can share uniforms across both vertex and fragment, but I'm confused what this is even compiling to if this is the case.
       
      #define NUM_LIGHTS 2
      struct Light
      {
          vec3 position;
          vec3 diffuse;
          float attenuation;
      };
      uniform Light Lights[NUM_LIGHTS];
       
       
    • By pr033r
      Hello,
      I have a Bachelor project on topic "Implenet 3D Boid's algorithm in OpenGL". All OpenGL issues works fine for me, all rendering etc. But when I started implement the boid's algorithm it was getting worse and worse. I read article (http://natureofcode.com/book/chapter-6-autonomous-agents/) inspirate from another code (here: https://github.com/jyanar/Boids/tree/master/src) but it still doesn't work like in tutorials and videos. For example the main problem: when I apply Cohesion (one of three main laws of boids) it makes some "cycling knot". Second, when some flock touch to another it scary change the coordination or respawn in origin (x: 0, y:0. z:0). Just some streng things. 
      I followed many tutorials, change a try everything but it isn't so smooth, without lags like in another videos. I really need your help. 
      My code (optimalizing branch): https://github.com/pr033r/BachelorProject/tree/Optimalizing
      Exe file (if you want to look) and models folder (for those who will download the sources):
      http://leteckaposta.cz/367190436
      Thanks for any help...

    • By Andrija
      I am currently trying to implement shadow mapping into my project , but although i can render my depth map to the screen and it looks okay , when i sample it with shadowCoords there is no shadow.
      Here is my light space matrix calculation
      mat4x4 lightViewMatrix; vec3 sun_pos = {SUN_OFFSET * the_sun->direction[0], SUN_OFFSET * the_sun->direction[1], SUN_OFFSET * the_sun->direction[2]}; mat4x4_look_at(lightViewMatrix,sun_pos,player->pos,up); mat4x4_mul(lightSpaceMatrix,lightProjMatrix,lightViewMatrix); I will tweak the values for the size and frustum of the shadow map, but for now i just want to draw shadows around the player position
      the_sun->direction is a normalized vector so i multiply it by a constant to get the position.
      player->pos is the camera position in world space
      the light projection matrix is calculated like this:
      mat4x4_ortho(lightProjMatrix,-SHADOW_FAR,SHADOW_FAR,-SHADOW_FAR,SHADOW_FAR,NEAR,SHADOW_FAR); Shadow vertex shader:
      uniform mat4 light_space_matrix; void main() { gl_Position = light_space_matrix * transfMatrix * vec4(position, 1.0f); } Shadow fragment shader:
      out float fragDepth; void main() { fragDepth = gl_FragCoord.z; } I am using deferred rendering so i have all my world positions in the g_positions buffer
      My shadow calculation in the deferred fragment shader:
      float get_shadow_fac(vec4 light_space_pos) { vec3 shadow_coords = light_space_pos.xyz / light_space_pos.w; shadow_coords = shadow_coords * 0.5 + 0.5; float closest_depth = texture(shadow_map, shadow_coords.xy).r; float current_depth = shadow_coords.z; float shadow_fac = 1.0; if(closest_depth < current_depth) shadow_fac = 0.5; return shadow_fac; } I call the function like this:
      get_shadow_fac(light_space_matrix * vec4(position,1.0)); Where position is the value i got from sampling the g_position buffer
      Here is my depth texture (i know it will produce low quality shadows but i just want to get it working for now):
      sorry because of the compression , the black smudges are trees ... https://i.stack.imgur.com/T43aK.jpg
      EDIT: Depth texture attachment:
      glTexImage2D(GL_TEXTURE_2D, 0,GL_DEPTH_COMPONENT24,fbo->width,fbo->height,0,GL_DEPTH_COMPONENT,GL_FLOAT,NULL); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, fbo->depthTexture, 0);
  • Popular Now