ExtrudeGeometry: Fix regression introduced by #30750.

[mlasala45]

Fixed #30819

Description

Changes introduced by #30750 resulted in the inputs to ShapeUtils.triangulateGeometry not being initialized when bevelSegments == 0 (which happens when bevelEnabled == false), causing triangulation to fail. This PR adds code to manually populate those lists if they are empty before triangulation, fixing the issue. See related issue for examples.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.08 78.29	336.08 78.29	+0 B +0 B
WebGPU	532.74 148.03	532.74 148.03	+0 B +0 B
WebGPU Nodes	532.21 147.93	532.21 147.93	+0 B +0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	465.09 112.16	465.09 112.16	+0 B +0 B
WebGPU	604.38 164	604.38 164	+0 B +0 B
WebGPU Nodes	559.37 153.45	559.37 153.45	+0 B +0 B

[mlasala45]

Maybe it would be worth having a test screenshot for bevelEnabled == false? I'm not familiar with the process for setting those up.

[WestLangley]

These new changes appear to be causing additional regressions. Also check the console errors.

https://threejs.org/examples/webgl_geometry_text.html // tested after merging this PR

I would be inclined to revert #30750 at this point and allow time for proper testing.

[mlasala45]

@WestLangley not seeing console errors, but I see the geometry bug (oddly, it's different on my end). I'll investigate.

[mlasala45]

Fixed. The change was using the wrong variable to populate contractedContourVertices, which would cause an error for shapes with holes when bevelEnabled == false. My bad, I should have tested the PR more thoroughly.

[WestLangley]

@WestLangley not seeing console errors, ...

The console errors occurred when the font was changed.

Unrelated to this PR, but FYI, file 8.svg from the webgl_loader_svg.html example does not extrude properly. It is just a rectangle with a single hole.

[mlasala45]

The console errors occurred when the font was changed.

Ah, yeah I did see those later. They're gone now that the variable is fixed.

Unrelated to this PR, but FYI, file 8.svg from the webgl_loader_svg.html example does not extrude properly. It is just a rectangle with a single hole.

@WestLangley It appears that the outside boundary is being classified as a hole, while the inside boundary is being classified as a contour. This is happening before it's passed to ExtrudeGeometry, so it's probably a defect with the SVG file itself, the SVGLoader, or path.toShapes(). The issue seems to predate #30750 though.

[WestLangley]

@gkjohnson I have done the best I can to identify the failure points. Someone other than myself will have to approve the code changes. 🙏

[gkjohnson]

I have done the best I can to identify the failure points. Someone other than myself will have to approve the code changes. 🙏

Sorry I missed that there were already other reviews on this PR somehow. I'm not an expert in this file but as this PR is addressing it looks like the tringulated arrays were not being populated if there were no bevel points. Using the "contour" and "holes" arrays should revert the behavior back to what it was before #30750 when bevels were disabled. This change also seems to work.

let faces;
if ( contractedContourVertices.length === 0 ) {

	faces = ShapeUtils.triangulateShape( contour, holes );

} else {

	faces = ShapeUtils.triangulateShape( contractedContourVertices, expandedHoleVertices );

}

[mlasala45]

Using the "contour" and "holes" arrays should revert the behavior back to what it was before #30750 when bevels were disabled.

@gkjohnson Good call. I've restructured this fix to check bevelSegments early, and avoid calculating contractedContourVertices and expandedHoleVertices when not necessary. The diffs show up poorly due to indentation changes, but the structure is now:

let faces;
if ( bevelSegments == 0 ) {

	faces = ShapeUtils.triangulateShape( contour, holes );

} else {
	// Calculate contractedContourVertices and expandedHoleVertices
	// ...

	faces = ShapeUtils.triangulateShape( contractedContourVertices, expandedHoleVertices );
}

[gkjohnson]

I think this looks good and ready to merge.