The crux of the idea is outlined in this question: https://community.safe.com/s/question/0D54Q00008VsdhhSAB/gltf-output-is-transparent-when-it-shouldnt-really-be
But the idea is this:
When writing out texture materials to GLTF (and 3DTiles) which contain and alpha channel (e.g., a png), change the default alphamode from BLEND to MASK.
This would solve many rendering issues which pop up from BLEND rendering.
This is not a one size fits all as BLEND could indeed be what is desiered so as follow up suggestion:
Add an option on the gltf reader to select the default alphamode - This is what is used when exporting from Blender (https://docs.blender.org/manual/en/2.80/addons/io_scene_gltf2.html).
A step further still would be to allow a geometry trait whitch could dictate which alphamode is used (e.g., gltf_alphamode).
At present this is a pretty big issue for us
