clayjohn
commented
4 years ago Implemented in https://github.com/godotengine/godot/pu ll/36588 and https://github.com/godotengine/godot/pull/36691
Closed clayjohn closed 4 years ago
clayjohn
commented
4 years ago Implemented in https://github.com/godotengine/godot/pu ll/36588 and https://github.com/godotengine/godot/pull/36691
Describe the project you are working on: The Vulkan rendering backend
Describe the problem or limitation you are having in your project: Currently environment map filtering is done at load time and is too slow for real time effects. On my hardware (GTX 1050) updating the radiance map for a panorama sky can take anywhere from 30-60 ms on high quality. This makes realtime updating of skies or reflection probes impossible.
Describe the feature / enhancement and how it helps to overcome the problem or limitation: 1) Implement this paper for low-quality realtime reflections (I have already done so on a local branch). 2) Improve the default high-quality importance sampling. 3) Alter the quality settings for radiance
Between the three of these we should be able to create high quality radiance maps in realtime for all levels of hardware. This is necessary before we implement real-time sky shaders. This is also helpful so that users can have realtime reflections.
Describe how your proposal will work, with code, pseudocode, mockups, and/or diagrams: 1) I will update with a link to my branch soon. 2) This will be done by sampling from a higher mip level from the environment based on roughness and PDF described here 3) I think the radiance quality setting should be "Offline" or "Realtime". "Offline" would always use the current array based importance sampling to get highest quality without any artifacts. Of course, for certain HDR maps, a higher number of samples will be needed, while this is extremely slow, it may be desired for high quality rendering needs. "Realtime" would have options for high-quality and low quality which can be configured in the project settings.
If this enhancement will not be used often, can it be worked around with a few lines of script?: This enhancement will be used by almost every Environment.
Is there a reason why this should be core and not an add-on in the asset library?: This feature modifies core parts of the Vulkan backend
Old Comparison
## Comparison ### HDR Environment Map (fast filtering excels) *Old Method*  *Fast Filtering*  ### Default Sky (fast filtering shows cubemap artifact) *Old Method*  *Fast Filtering* Updated Comparison (23/02/2020)
Using Arrays
Current "High Quality": 1024 tap importance sampling
Fast Filtering: High Quality
Fast Filtering: Low Quality
Not Using Arrays
Current "High Quality": 1024 tap importance sampling
Fast Filtering: High Quality
Fast Filtering: Low Quality
The Numbers
Everybody's favourite part I know 😋
1,000 us = 1ms 1,000 ms = 1 second
*Array methods also have an extra 900 us overhead to generate mipmips, this can be spend up using compute