mrdoob
Nodes: Line2NodeMaterial dash mode broken
Description
The PR #28585 appears to have broken Line2NodeMaterial. Reverting the PR fixes the error.
In dashed mode, the fragment shader fails to compile with the error in
https://github.com/mrdoob/three.js/blob/0679c557066907c19659697deaa3d2d0b0c7e724/src/nodes/materials/Line2NodeMaterial.js#L269
If the multiplications within the cond() expression are removed, the shader compiles as expected.
Reproduction steps
- run the example webgpu_lines_fat
- select 'dashed' to enable dashed line mode.
Code
n/a
Live example
Screenshots
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Version
166
Device
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I had a few issues with cond() as well when porting code to TSL. Out of curiosity, does it work if the code is change to the following?
const lineDistance = float( 0 ).toVar();
If( positionGeometry.y.lessThan( 0.5 ), () => {
lineDistance.assign( dashScaleNode.mul( instanceDistanceStart ) );
} ).else( () => {
lineDistance.assign( materialLineScale.mul( instanceDistanceEnd ) );
} );
Yes and no (with a float( 0 ).toVar();
It doesn't produce an invalid shader, but doesn't work as expected. Presumably because If() uses cond() internally.
Ah yes, the toVar() is required in this case.
In any event, this was just intended as a possible workaround. Of course it's best to make the normal cond() usage work.