Created attachment 789287 [details]
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.95 Safari/537.36
Steps to reproduce:
Create large amount of elements with 3D Transformation applied.
Wrong visibility calculation. Elements cover each other in wrong order.
Right visibility calculation.
problem is common for all FF versions
Created attachment 790166 [details]
this is screenshot of expected behaviour
Created attachment 790172 [details]
this is screenshot of behaviour in Gecko on a small amount of elements
Created attachment 790174 [details]
this is screenshot of behaviour in Gecko on a big amount of elements
I assume this is just the lack of plane splitting. Currently we have some heuristics for z-ordering 3D transformed elements that don't always work. I.e., bug 689498.
In addition to the plane splitting being required for correct rendering in many cases, there is currently a hard-coded limit to the number of layers that will be sorted:
This is currently set to 100. When the layer sorting is fixed, this limit will be bumped up to a more reasonable ceiling that is less likely to be hit.