Sampling a texture in a VertexShader not supported ?

Graphics
1

Using a Tex2D(…) call in a VertexShader appears to be unsupported by the current Shader Compiler ?
error X4532: cannot map expression to vertex shader instruction set

Is there another way to sample a texture from within a VertexShader ?

On a related note, I tried compiling the shader using a MonoGame branch with ShaderConductor but then I get an error about the Tex2D intrinsic is deprecated although I can’t find what it’s been replaced with.
Does anyone know how I would re-write the Tex2D call in the VertexShader to work with ShaderConductor ?

2

Definitely supported, however sampler in Vertex Shader can’t decide which minmap to use (as this is pre rasterization), hence it need to be specified, for example as Texture.SampleLevel(SamplerState, uvCoords, 0)

1 Like
3

Thank you, will give this a go.

4

ops, I don’t know how it happened but i forget “Level” in “Sample” sorry, check edit for correction.

5

No hassles, thanks for fixing it.

However… I’ve run into new (unrelated) issues that I think I’ll open a different ticket for.

But in short, my project was a DesktopGL project, but it appears the shader compiler doesn’t support that syntax for OpenGL. So I created a new DirectX project and your sample code compiles fine.

  • float4 data = Texture0.SampleLevel(TextureSampler0, float2(_x, _y), 0);

However, at runtime I get the below when trying to load the effect in the DirectX project.
‘This MGFX effect was built for a different platform!’

MGCB seems to be passing the correct platform switch (/platform:Windows), so not sure what’s going on

6

I would try to hard specify Windows platform in your mgcb project

7

You said that you were using the ShaderConductor fork. Texture.SampleLevel() should work fine there, both in DX and GL.

8

Thanks, will try that.