Pick transparent primitives


On a old Cesium version I could use scene.pick(position) to get primitives with alpha color = 0. Now, when the primitive is transparent scene.pick(position) returns undefined. Is there a way to get transparent primitives by click?

I use it to select a no filled polygon. I build a polygon and a polyline. I set the alpha of the polygon to zero and the user can click inside the polygon to select it.


Hi Tamy,

This sounds like a bug in the older version. Try setting the alpha to something small like 0.05. It will be pickable, but you probably won’t see it.


I sometimes use 0.004, because 0.004 * 255 == 1.02, so it’s the smallest value that won’t disappear when placed in an 8-bit Alpha channel.


Good idea! Thank you!