1800177 - Twisting CSS Cube is slow in Firefox

Status: NEW

(Core :: Graphics: WebRender, defect)

Description

[Gregory Pappas [:gregp]]

Steps to reproduce:

1. Navigate to https://codepen.io/davidkpiano/full/QjremP

Actual results:
Jank

Expected results:
Less jank

https://share.firefox.dev/3EmE3p9

Comment 1

[Jeff Muizelaar [:jrmuizel]]

This is 3d transforms related

Comment 2

[Nicolas Silva [:nical]]

Looks like the biggest issue is the same as in bug 1768984, there are thousands of draw calls.

Comment 3

[Jeff Muizelaar [:jrmuizel]]

It looks like there are 32 slices. Why do we have more than 32 * 8 = 256 draw calls?

Comment 4

[Nicolas Silva [:nical]]

I don't know. Without digging into it, my guess is that plane splitting is generating a large number of planes and at certain angles the ordering of the parts has us ping-ponging between lots of small parts of the original slices.

Comment 5

[Jeff Muizelaar [:jrmuizel]]

I wouldn't expect there to be any splits. It doesn't look like any of the surfaces should be intersecting.