Debug lines in Cesium 120

CesiumJS
1

When using CesiumJS 1.120.0 I see some debug lines on my 3D Tiles model

Demo: Klic 3D

debug_lines

When using CesiumJS 1.119.0 this does not happen

demo: Klic 3D

2

Looks like something screen based. Maybe something with the near frustum?

delme

3

I’ve only seen it in 120, not in 119 (all other things are the same)

4

That’s strange. I also saw them a while ago, and did try it out with older versions (going back to ~1.110 or so), and saw them there as well, but… apparently, I messed something up during this test (maybe forgot to recompile or something - this was only a distracting side-track while debugging other stuff…)

For now, I can only confirm that the issue is there, and … a quick git bisect points to Update Smith visibility function for PBR materials · CesiumGS/cesium@fce86ad · GitHub where this was introduced.

I didn’t do the math of what’s happening there, but the pattern of
if (x > 0) return something / x;
looks prone to epsilon-errors, like x being 1e-10 and the result being “nearly infinity” then. Shrugging and changing this line to
if (GGX > 0.01)
seems to ““fix”” it, but others have to look at what makes most sense there.

1 Like
5

Opened Rendering artifacts on flat surfaces · Issue #12109 · CesiumGS/cesium · GitHub to keep track of this. (It looks like it might be an easy fix, but still to be investigated…)

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