1. A concise explanation of the problem you’re experiencing.
When adding a polygon with an ImageMaterial to cesium using the COLUMBUS_VIEW makes white parts of the PNG used in the material grey. Changing to 3D view makes the PNG appear with the correct colours, maybe a little bit over saturated.
Problem 2 which I can not reproduce in the sandcastle link below. When drawing two polygons with material on top of each other makes the second polygon which should be above the first disappear, including any drawn billboards or other objects at certain zoom levels but only in Chrome and Safari.
2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.
3. Context. Why do you need to do this? We might know a better way to accomplish your goal.
I need to draw two Geo-referenced images on top of each other. The first one is a map and the second is a transparent image with a route. These two images might be geo-referenced slightly different. Maybe there is a better more accurate way than using a polygon?
4. The Cesium version you’re using, your operating system and browser.
The first problem happens in 1.37+ any browser and any OS
The second I haven’t been able to reproduce in the sandcastle so only 1.37. But looking through the change log I haven’t seen anything that might fix this in any later version. But it happens consistently in Chrome and Safari on Mac.