beginShape(TESS) only works on faces facing the camera

[davepagurek]

Most appropriate sub-area of p5.js?

• Accessibility
• Color
• Core/Environment/Rendering
• Data
• DOM
• Events
• Image
• IO
• Math
• Typography
• Utilities
• WebGL
• Build Process
• Unit Testing
• Internalization
• Friendly Errors
• Other (specify if possible)

p5.js version

1.5.0

Web browser and version

Firefox 107.0

Operating System

MacOS 12.5.1

Steps to reproduce this

When using beginShape(TESS), we perform a 2D tesselation, and projecting the points into 2D along the normal specified here:

https://github.com/processing/p5.js/blob/main/src/webgl/p5.RendererGL.js#L1501

This works for faces that face the camera, but breaks on faces that are perpendicular to the camera, leaving holes e.g. in this sketch: https://editor.p5js.org/davepagurek/sketches/HLO-ZN5Vg