pick Functions cause camera problem in requestRenderMode

[mramato]

Long story short, if you are in requestRenderMode mode, you have to put a scene.requestRender call after every scene.pick/scene.drillPick or similar picking function. Otherwise the next camera action, such as rotating around a building, will pick through the object and into what it thinks is empty space.

Without knowing a ton about the picking code, it seems to me the easy fix is to make all of the pick functions simply issue a requestRender call themselves rather than force all of our users to learn this lesson the hard way.

Here's a Sandcastle you can use

1. Zoom in on a building
2. Wait for the scene to load completely (this is important because if Cesium is continually rendering the bug doesn't happen).
3. Middle mouse rotate around the building slightly (not a huge movement, you don't want to trigger more tiles loading in)

You may have to do step 3 multiple times, but after a few tries it will definitely happen. If you uncomment out the requestRender call, the problem goes away.

CC @lilleyse @IanLilleyT I think you've both been in the picking code recently, thoughts?

[lilleyse]

Without knowing a ton about the picking code, it seems to me the easy fix is to make all of the pick functions simply issue a requestRender call themselves rather than force all of our users to learn this lesson the hard way.

This seems like a good fix to me.

[anne-gropler]

Without knowing a ton about the picking code, it seems to me the easy fix is to make all of the pick functions simply issue a requestRender call themselves rather than force all of our users to learn this lesson the hard way.

This seems like a good fix to me.

This is not a good fix, because it will lower performance. Use cases like #11031 would be unmanagable..