Hi,
I’m attempting to render a volumetric texture in 4.25, and it seems regardless of what I try I’m unable to get a volume shader to work. I’ve tried the following:
- Using a Material in the “Volume” domain with a constant extinction, and either constant float4 for emission or volumetric texture parameter, multiplied by an intensity modifier, and a parameteric float3 for albedo. I’ve varied the values of each parameter, such as the extinction between [0,1] and emissive between [0,1000], to attempt to get any response, including using a brain tomography scan as well as 3D perlin noise as possible texture inputs. Nothing appeared in the shader preview, or in the world when doing this.
- I’ve tried transforming the volumetric sliced textures into Volume Materials via the in-engine system. I’ve used both the “Trace in Volume” and “Depth Slices” view modes to verify that the volumetric texture is having proper slicing behavior for each tile, and that they appear as volumetric cubes or rectangular prisms (depending on tile-size variance) in the “Trace in Volume” preview. Plugging these into the above described model doesn’t work.
- I’ve tried using an Unlit model with emissive textures plugged in, but this just gave me the result of each slice of the texture being displayed on a portion of the emissive surface, as one might expect from a normal surface-domain shader.
Other things to mention:
- I made sure to select “additive” blending mode for all shaders.
- I added
r.AllowVolumeTextureAssetCreation=1toDefaultEngine.ini, under a new[/Script/Engine.RendererSettings]block just to make sure it wasn’t the source of the problem. - I’ve tried referencing this page in the engine documentation, and others under that section to no result.
- I’ve tried referencing some of Ryan Bruck’s blog posts on volumetrics, though I have not gone through the process of implementing his full ray-marcher approach.
- I’ve looked at the “Working with Volumetrics” video from August 2020, but that was in engine version 4.26, and seemed to be behaving differently for me.
The result of all the attempts, besides the one described under the unlit shader above, is a completely invisible shader, and completely invisible objects when applied to them in the world.