Personal terrain and transparency of terrain


1/ I want to use my own terrain for a part of the globe is it possible?
   I only found groundpush, but is there another possibility?

2/ I have seen that the terrain of cesium is a bit transparant. I seen some objets wich are under the ground, and so I souldn't see it!

Is there some possibilities?

thanks in advance

Using your own terrain source/server is possible, but I believe it’s all or nothing. I think you can only set a single terrain source at a time.