Tiled Forward Rendering

SeanOMik commented

2024-03-17 19:25:23 +00:00

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Tiled forward rendering is a very common rendering technique for rendering scenes with many many lights. In short, it uses a grid of tiles, that uses a compute shader to cull the lights in each tile. Then the fragment shader uses the results of the compute shader, and only calculates the lighting for each light in each tile instead of all lights.

Resources:

Note: All screenshots shown in this PR are taken from a window that is 800x600 unless labeled otherwise.

Tiled forward rendering is a very common rendering technique for rendering scenes with many many lights. In short, it uses a grid of tiles, that uses a compute shader to cull the lights in each tile. Then the fragment shader uses the results of the compute shader, and only calculates the lighting for each light in each tile instead of all lights. Resources: * https://www.3dgep.com/forward-plus * https://github.com/bcrusco/Forward-Plus-Renderer Note: All screenshots shown in this PR are taken from a window that is 800x600 unless labeled otherwise.

SeanOMik added 6 commits 2024-03-17 19:25:24 +00:00

22c08ba66e

render: improve the render buffer wrapper, use it for the camera uniform

cfd5cabfbb

render: create light cull compute shader, bind buffers, etc.

1818a0b48b

position the camera in a good position in the scene

4ce21d4db0

render: dont send the same material to the gpu multiple times, speeding up gpu texture loading

c73c1a7f43

render: fix segfault in LightCullCompute

5c1ce809ff

render: get some lights showing up with tiled forward rendering

For some reason there's weird square in the light source, and the dynamic light is only applied to the top left tile

SeanOMik commented

2024-03-17 19:31:24 +00:00

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This has already been worked on before I made this PR. Here's a screenshot of the id of the tile as red and green in the fragment shader, with some lines:

This is the sponza scene with a blue point light rendered with forward+:

The top left tile appears to be the effects of the directional light in the scene. There is also a weird slightly darker square in the point light on the floor, it moves around with the camera.

This has already been worked on before I made this PR. Here's a screenshot of the id of the tile as red and green in the fragment shader, with some lines: ![image](/attachments/1d5df5f8-78e1-477c-b5ca-23cfc41a15ec) This is the sponza scene with a blue point light rendered with forward+: ![image](/attachments/e2cb16e1-1863-456a-8a14-3dfd3176c149) The top left tile appears to be the effects of the directional light in the scene. There is also a weird slightly darker square in the point light on the floor, it moves around with the camera.

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SeanOMik added 1 commit 2024-03-17 20:07:48 +00:00

76ec9606ec

render: add some fields to the camera uniform

SeanOMik force-pushed feature/tiled-forward-rendering from a0b1e90bc6 to 834a864544

2024-03-20 01:18:48 +00:00

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SeanOMik added 1 commit 2024-03-20 01:40:11 +00:00

f63a7ae86a

include correct rust install in nix-shell

SeanOMik added 2 commits 2024-03-20 15:42:01 +00:00

65ff7c4f23

render: retrieve light properties from components

f0b413d9ae

render: resize light grid with window, improve light buffer, add spot lights to the light cull compute

Spot lights are buggy. They get culled when they shouldn't be, maybe still an issue with the light grid :(

SeanOMik added 1 commit 2024-03-20 23:03:50 +00:00

e2844a11a6

render: create toggleable debug light cull view

SeanOMik commented

2024-03-20 23:50:31 +00:00

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Tiled forward rendering is finally working!

I also added a triggerable debug view that shows the amount of lights in each tile (by pressing B). The brightness of each tile is number of lights in tile / total number of lights

Keep in mind that no optimizations have been made to the culling (i.e., AABB culling for point lights) so the culling isn't super accurate.

I did a bit of work to get spot lights working, but the light gets cutoff when moving closer to it:

A bug was also discovered that made it so the same mesh can't be shared between models which is why there aren't boxes at each light source in the above images.

Tiled forward rendering is finally working! ![image](/attachments/f5742c21-90af-4246-b747-8f109d8b37b1) I also added a triggerable debug view that shows the amount of lights in each tile (by pressing B). The brightness of each tile is `number of lights in tile / total number of lights` ![image](/attachments/d089f426-1448-48da-b529-eb43fdd2a1b4) Keep in mind that no optimizations have been made to the culling (i.e., AABB culling for point lights) so the culling isn't super accurate. I did a bit of work to get spot lights working, but the light gets cutoff when moving closer to it: ![image](/attachments/c90f6dca-fda2-4a0a-811d-b67f2aa64028) A bug was also discovered that made it so the same mesh can't be shared between models which is why there aren't boxes at each light source in the above images.

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SeanOMik added 1 commit 2024-03-22 14:46:55 +00:00

0f11fe2e6d

render: fix spot light culling

SeanOMik commented

2024-03-22 16:16:08 +00:00

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Spot light culling was fixed, but in a non-optimal way. I couldn't figure out the issue with the math that checked if a cone was in the frustum, so I just treat the spotlight as a point light for culling. This is okay for now since optimizations for spotlight culling would replace the frustum culling.

SeanOMik added the

Kind/Feature

label 2024-03-23 02:24:29 +00:00

SeanOMik added 1 commit 2024-03-23 02:55:19 +00:00

763d51ae36

move some stuff out of testbed into lyra-game

SeanOMik changed title from ~~WIP: Tiled Forward Rendering~~ to Tiled Forward Rendering

2024-03-23 14:35:10 +00:00

SeanOMik commented

2024-03-23 14:38:35 +00:00

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This can be considered complete. The performance is pretty poor, but for that I need to profile the engine to see what is taking up a lot of time. There can be future PRs for improving the performance of the renderer.

With 500 lights in the sponza scene I get ~180fps (release build, vsync disabled) when looking at the scene with the lights, or ~250fps when looking away.

This can be considered complete. The performance is pretty poor, but for that I need to profile the engine to see what is taking up a lot of time. There can be future PRs for improving the performance of the renderer. With 500 lights in the sponza scene I get ~180fps (release build, vsync disabled) when looking at the scene with the lights, or ~250fps when looking away.

SeanOMik merged commit 763d51ae36 into main

2024-03-23 14:38:43 +00:00

SeanOMik deleted branch feature/tiled-forward-rendering

2024-03-23 14:38:43 +00:00

SeanOMik referenced this pull request

2024-04-24 22:54:44 +00:00

Improve Performance in Scenes With Many Lights #14

Tiled Forward Rendering #5