Finishing Debugging Volume Textures — Handmade Hero — Episode Guide

0:03Recap and set the stage for the day

0:38Fix the monitor's colour

1:55Resume our investigations into the volume texture lookup

4:46Determine to use structured art to verify that we are transmitting the correct values

7:58handmade_render_group.cpp: Make OutputLightingTextures() write a monotonically increasing value into the lookup sampler

10:30handmade_opengl.cpp: Make CompileZBiasProgram() use that value directly

13:12handmade_render_group.cpp: Temporarily disable OutputTextureDebug()

13:55Run the game and see nothing

15:03handmade_world_mode.cpp: Prevent UpdateAndRenderWorld() from calling OutputLighting()

16:32Run the game and hunt for a key binding to capture a frame

18:53Capture a frame and see that the lookup sampler contains all 0

20:18Run the game, run PushLighting() and capture a frame to see our expected values in the lookup sampler

21:55handmade_render_group.cpp: Make OutputLightingTextures() set the fragment shader's lighting texels and colour to known values

25:16Capture a frame, but find that the compiler has optimised out the lighting texels and colour

26:33handmade_opengl.cpp: Investigate why the texelFetch in CompileZBiasProgram() is not using our structured art, with a few words on graphics programming

31:13handmade_opengl.cpp: Verify VoxP in CompileZBiasProgram() by colouring the voxels by their address

32:21Run the game to see our colour-coded representation of the voxel lookup

33:10handmade_opengl.cpp: Make CompileZBiasProgram() set the colour from the VoxP after flooring

33:41Run the game to see that this is still as expected

34:48handmade_opengl.cpp: Make CompileZBiasProgram() perform texelFetch() on our verified values

36:59Run the game and still see black

37:28Consult the OpenGL Shading Language Specification for texelFetch()¹

44:08handmade_opengl.cpp: Initialise LightI as a uint, and continue to wonder why we are not successfully fetching from the LookupSampler

50:48handmade_opengl.cpp: Try setting the UseLightC to individual colours from the LookupSampler, to see exactly what texelFetch() returns

54:39Run the game to see that the alpha channel unexpectedly is a high value before submitting the texture

56:03Reflect on our findings, that texelFetch() is returning 0, 0, 0, 1

1:00:54macielda Maybe up your level of debug message notifications?

🗪

1:00:54macielda Maybe up your level of debug message notifications?

🗪

1:00:54macielda Maybe up your level of debug message notifications?

🗪

1:01:12handmade_opengl.cpp: Print out all of the debug messages

1:03:32bestalloys 3rd comment: https://stackoverflow.com/questions/26770216/why-is-texelfetch-always-returning-0-for-a-1d-single-channel-texture

🗪

1:03:32bestalloys 3rd comment: https://stackoverflow.com/questions/26770216/why-is-texelfetch-always-returning-0-for-a-1d-single-channel-texture

🗪

1:03:32bestalloys 3rd comment: https://stackoverflow.com/questions/26770216/why-is-texelfetch-always-returning-0-for-a-1d-single-channel-texture

🗪

1:07:05handmade_opengl.cpp: Make OpenGLChangeToSettings() set GL_TEXTURE_MIN_FILTER and GL_TEXTURE_MAG_FILTER to GL_NEAREST

1:11:47Run the game to see that this totally fixed it, and wonder why texelFetch() applied filtering

1:15:44Consult the OpenGL Specification for texelFetch()²

1:19:02Read about Texture Completeness³

1:23:05handmade_opengl.cpp: Enable CompileZBiasProgram() to use our structured art fetched from the LookupSampler

1:32:53handmade_opengl.cpp: Enable CompileZBiasProgram() to sample our real lighting values

1:34:01Run the game to see that we are getting the colours we'd expect

1:34:45handmade_opengl.cpp: Make the lighting grid more coarse

1:36:17Run the game and note that we are not covering all the space with light

1:37:18handmade_opengl.cpp: Introduce SumVoxelLight() to enable CompileZBiasProgram() to sample from neighbouring voxels

1:46:03Run the game to see that running fast

1:47:48handmade_opengl.cpp: Make CompileZBiasProgram() modulate the texture colours by the lighting values

1:48:29Run the game to see our lit scene

1:48:51handmade_opengl.cpp: Enable CompileZBiasProgram() to weight the lighting values by their proximity

1:52:24Run the game to see that we don't have dense enough lighting coverage

1:52:48handmade_opengl.cpp: Make the lighting grid more fine grained

1:53:09Run the game to see our more smoothly lit scene

1:55:01handmade_opengl.cpp: Change the coarseness of the lighting grid

1:56:49Q&A

🗩

1:56:49Q&A

🗩

1:56:49Q&A

🗩

1:57:14bestalloys Why no indentation on the shader code?

🗪

1:57:14bestalloys Why no indentation on the shader code?

🗪

1:57:14bestalloys Why no indentation on the shader code?

🗪

1:58:29butwhynot1 Have you tried CUDA? Do you think it's a reasonable way to do GPU programming? AMD is trying to get a CUDA compatible compiler so it could be usable on both vendors soon

🗪

1:58:29butwhynot1 Have you tried CUDA? Do you think it's a reasonable way to do GPU programming? AMD is trying to get a CUDA compatible compiler so it could be usable on both vendors soon

🗪

1:58:29butwhynot1 Have you tried CUDA? Do you think it's a reasonable way to do GPU programming? AMD is trying to get a CUDA compatible compiler so it could be usable on both vendors soon

🗪

2:00:284bitlightning Could you try to use #include and the multi line strings together for the shader code?

🗪

2:00:284bitlightning Could you try to use #include and the multi line strings together for the shader code?

🗪

2:00:284bitlightning Could you try to use #include and the multi line strings together for the shader code?

🗪

2:01:20poohshoes I've just started a project and am working through the setup on Day 002. You had set up a PatBlt on WM_PAINT to alternate black and white. If I made no mistakes then it doesn't work on windows 10, I'm instead getting all white and if I drag the window around, the new part of the window becomes black? Do you know if there are any caveats for windows 10 I should be worried about? Should I keep going or is it important to get this working exactly the same?

🗪

2:01:20poohshoes I've just started a project and am working through the setup on Day 002. You had set up a PatBlt on WM_PAINT to alternate black and white. If I made no mistakes then it doesn't work on windows 10, I'm instead getting all white and if I drag the window around, the new part of the window becomes black? Do you know if there are any caveats for windows 10 I should be worried about? Should I keep going or is it important to get this working exactly the same?

🗪

2:01:20poohshoes I've just started a project and am working through the setup on Day 002. You had set up a PatBlt on WM_PAINT to alternate black and white. If I made no mistakes then it doesn't work on windows 10, I'm instead getting all white and if I drag the window around, the new part of the window becomes black? Do you know if there are any caveats for windows 10 I should be worried about? Should I keep going or is it important to get this working exactly the same?

🗪

2:02:19nxsy Do you have any suggestions on how to start going about voxelising more complex 3D meshes rather than simpler geometric shapes? Break them up into simpler geometric version / LOD meshes first? Should each mesh be pre-voxelised, or do you need to recalculate relative to the world / view position (and possibly distance from camera)?

🗪

2:02:19nxsy Do you have any suggestions on how to start going about voxelising more complex 3D meshes rather than simpler geometric shapes? Break them up into simpler geometric version / LOD meshes first? Should each mesh be pre-voxelised, or do you need to recalculate relative to the world / view position (and possibly distance from camera)?

🗪

2:02:19nxsy Do you have any suggestions on how to start going about voxelising more complex 3D meshes rather than simpler geometric shapes? Break them up into simpler geometric version / LOD meshes first? Should each mesh be pre-voxelised, or do you need to recalculate relative to the world / view position (and possibly distance from camera)?

🗪

2:04:08nxsy Not necessarily doing it on the GPU, but to provide what the GPU needs to do this sort of lighting with more complex meshes

🗪

2:04:08nxsy Not necessarily doing it on the GPU, but to provide what the GPU needs to do this sort of lighting with more complex meshes

🗪

2:04:08nxsy Not necessarily doing it on the GPU, but to provide what the GPU needs to do this sort of lighting with more complex meshes

🗪

2:06:54Blackboard: 2D rasterization

2:08:16Blackboard: Conservative rasterization

2:12:17Blackboard: Faster voxelization, using Reyes rendering⁴

2:17:24Recommend crawling references⁵

📖

2:17:24Recommend crawling references⁵

📖

2:17:24Recommend crawling references⁵

📖

2:22:29Close down the stream

🗩

2:22:29Close down the stream

🗩

2:22:29Close down the stream

🗩

Keyboard Navigation

Global Keys

Menu toggling

In-Menu and Index Controls

Quotes and References Menus and Index

Quotes, References and Credits Menus

Filter Menu

Filter and Link Menus

Credits Menu