I am currently looking into the issue of inconsistent display of overlapping transparent elements. While it is possible to enforce consistency by turning off "depth write" on transparent materials, this is an issue with LDraw since color 16 can be both transparent and opaque depending on the color to which it is assigned. As materials are combined, this is causing issues for BFC mode and for materials with both transparent and opaque sections.
I will instead look into the possibilities of using 3 materials per element (there is currently only one, hence the issues!)
1) Opaque material with depth write - This is rendered first
2) Color 16 material where depth write can be turned on and off - This is rendered second (so after any opaque material if 16 is a transparent color)
3) Transparent material without depth write - This is rendered last
This should fix the issues that we are currently observing on parts with mixed transparent and opaque sections. However. It requires some refactoring which might take me all weekend to get right.
I will instead look into the possibilities of using 3 materials per element (there is currently only one, hence the issues!)
1) Opaque material with depth write - This is rendered first
2) Color 16 material where depth write can be turned on and off - This is rendered second (so after any opaque material if 16 is a transparent color)
3) Transparent material without depth write - This is rendered last
This should fix the issues that we are currently observing on parts with mixed transparent and opaque sections. However. It requires some refactoring which might take me all weekend to get right.