CustomMaterial and non boolean shader defs

[KirmesBude]

Hi,

Using the shader_def example as a base, I am trying to add a uint shader def to my custom material.

impl Material for CustomMaterial {
    fn fragment_shader() -> ShaderRef {
        "shaders/shader_defs.wgsl".into()
    }

    fn specialize(
        _pipeline: &MaterialPipeline<Self>,
        descriptor: &mut RenderPipelineDescriptor,
        _layout: &MeshVertexBufferLayout,
        key: MaterialPipelineKey<Self>,
    ) -> Result<(), SpecializedMeshPipelineError> {
        if key.bind_group_data.is_red {
            let fragment = descriptor.fragment.as_mut().unwrap();
            fragment.shader_defs.push(ShaderDefVal::UInt("COLOR".into(), 0));
        }
        Ok(())
    }
}

struct CustomMaterial {
    color: vec4<f32>,
};

@group(1) @binding(0)
var<uniform> material: CustomMaterial;

@fragment
fn fragment(
    #import bevy_pbr::mesh_vertex_output
) -> @location(0) vec4<f32> {
#if COLOR == 0
    return vec4<f32>(1.0, 0.0, 0.0, 1.0);
#elseif COLOR == 1
    return vec4<f32>(0.0, 1.0, 0.0, 1.0);
#else
    return material.color;
#endif
}

But I am faced with the following error message:

ERROR bevy_render::render_resource::pipeline_cache: failed to process shader: Unknown shader def: 'COLOR'

Are non-boolean shader defs not supported for custom materials or am I doing something wrong?

[KirmesBude]

Alright, I get it now.
In the example I posted I check the Materal Key and only add the shader define, when is_red is true. Otherwise the define is not added at all.

So I should either check via #ifdef if the define exists in the shader code or I should always add this define and only change the value based on the key.