Raycaster only works on the first triangle of the BufferGeometry

Description of the problem

I have textured quads built using BufferGeometry with 4 vertices. It is in fact rendered using rasterMesh.drawMode = THREE.TriangleFanDrawMode.

Three.js version

• r79
• r81
• Dev

Browser

• All of them
• Chrome
• Firefox
• Internet Explorer

OS

• All of them
• Windows
• Linux
• Android
• IOS

Hardware Requirements (graphics card, VR Device, …)

[donmccurdy]

glTF allows triangle strips, how is three.js not allowing triangle strips “pigeon-holing”?

@Dmarcoux111 that a feature exists in WebGL is not a sufficient argument. We maintainers have to deal with feature requests and bug reports or supposed bug reports (why does ____ not work?) that consume our time. Every time someone reports that raycasting doesn’t work, or skinning is broken, we have to investigate why that is. Maintaining and debugging code paths for different draw modes cost us time and energy that could be spent on other things, and especially when features don’t work in all cases, we get more bug reports.

If you’d like to share specific performance numbers about why triangle strips are really better for your application, that would be a better line of argument than saying we have to maintain abstractions for this just because it exists in WebGL.

[Mugen87]

Some more thoughts about this topic:

In context of lines, we have Line, LineLoop and LineSegments which implicitly encode the draw mode and other primitive specific information (e.g line distances).

In Mesh, we just have a drawMode property instead. So the current design was never consistent. It would be if there were something like TriangleMesh, TriangleFanMesh and TriangleStripMesh. But I don’t think it’s beneficial to have such classes.