Post-processing#

A pass names its inputs and outputs and runs at its declared position in the render graph. Custom fullscreen effects define postprocess in WGSL. For a final color grade, replace the body of present:

tecs.gpu.passes.setShader("present", [=[
fn postprocess(uv: vec2<f32>) -> vec4<f32> {
    let color = textureSample(input0, passSampler, uv);
    let gray = dot(color.rgb, vec3<f32>(0.2126, 0.7152, 0.0722));
    return vec4<f32>(mix(color.rgb, vec3<f32>(gray), params.values[0].x), color.a);
}
]=])
tecs.gpu.passes.setParameters("present", {0.5})

The renderer supplies input0, input1, and subsequent textures in the order of the pass's inputs, plus passSampler and the scene uniform. A depth input is texture_depth_2d; read it with textureLoad. Parameters occupy four vec4 values, so the first four numbers are params.values[0]. Omitted numbers are zero. Setting the same values does nothing; changing parameters updates a uniform without recompiling shaders or reallocating render targets.

Composited color uses premultiplied alpha. Preserve that convention when returning translucent colors; the final pass blends over the window clear color. Emission and bloom may carry RGB even where alpha is zero.

To chain effects, declare a target, then insert a pass before the next consumer. Supply shader and optional parameters in the pass declaration. A pass can read only targets produced earlier, cannot read its own output, and a custom effect writes one color target. Empty outputs draw into the presentation image. Targets with scale = 0.5 have half the width and height. A depth-attached pass must use full-size targets.

The built-in names remain insertion points: geometry, lighting, bloomExtract, bloomBlurX, bloomBlurY, composite, forward, and present. Custom bodies execute regardless of the bloom and shadow toggles. In a scene with multiple views, the graph runs independently for each view.

Run nupp task ex-postprocess for a grayscale and vignette effect.