1. A concise explanation of the problem you’re experiencing.
CallbackProperty causes GPU churn with requestRenderMode toggled on. I have attached a sandcastle to reproduce this problem. If you comment out the “plane:plane” the GPU usage stops correctly.
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.
4. The Cesium version you’re using, your operating system and browser.
Thanks for bringing this up and providing a complete code example! I think this might be related to this issue, where a SampledPositionProperty breaks the requestRenderMode in the same way:
I bumped it with a link to this thread. It sounds like this is expected because a CallbackProperty marks this entity as dynamic and thus it will always think it requires rendering every frame. It would be nice if there was a way to mark an Entity as requiring an update manually. I had clone the position to force this, but even then it doesn’t update in the same frame.