Stride Shader (Filter) naming conventions and (hidden) keys and variables from Base Classes

schlonzo · September 6, 2023, 9:46am

hi all,

When I create a new Shader(Filter), the input texture texture is called “tex0col”. I had a look into the Edge shader, which also inherits from : FilterBase, but there the texture is called “Texture0”. Is there a naming convention behind these names?

“Texture0TexelSize”… is this similar to beta’s “invtargetsize”, and can I put this postfix behind any texture resource to access its dimensions? (MyTextureTexelSize.xy?)

What exactly does “WantsMips” do? (Because the shader also works of I do not generate mips for my texture?

I could not find reference code using the shader explorer.
Also checked the Stride documentation, but just found one entry in “shadowmapbase”

Some pointers would be helpful.

bjoern · September 6, 2023, 10:24am

These are pre-defined by stride and in case of the TFX refer to the respective texture inputs.

tex0col is there for convenience I assume, so in a simpler case you don’t have to sample yourself.

github.com

vvvv/stride/blob/master/sources/engine/Stride.Graphics/Shaders/Texturing.sdsl

// Copyright (c) .NET Foundation and Contributors (https://dotnetfoundation.org/ & https://stride3d.net) and Silicon Studio Corp. (https://www.siliconstudio.co.jp)
// Distributed under the MIT license. See the LICENSE.md file in the project root for more information.
shader Texturing
{
    // Default texture slots - might be automatically used by the material
    stage Texture2D Texture0;
    stage float2 Texture0TexelSize;
    stage Texture2D Texture1;
    stage float2 Texture1TexelSize;
    stage Texture2D Texture2;
    stage float2 Texture2TexelSize;
    stage Texture2D Texture3;
    stage float2 Texture3TexelSize;
    stage Texture2D Texture4;
    stage float2 Texture4TexelSize;
    stage Texture2D Texture5;
    stage float2 Texture5TexelSize;
    stage Texture2D Texture6;
    stage float2 Texture6TexelSize;
    stage Texture2D Texture7;

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Afaik WantsMips tells the “upstream” shader to generate mipmaps.

Idk what happens if you use SampleLevel with a texture that has no mips. I’d guess it then just defaults to Level 0?

motzi · September 6, 2023, 11:53am

You can select the var and ShaderExplorer shows you where it is defined (and also click it to go to the definition).

“Texture0TexelSize”… is this similar to beta’s “invtargetsize”, and can I put this postfix behind any texture resource to access its dimensions? (MyTextureTexelSize.xy?)

yes, you can use it anywhere if it is inheriting from Texturing