[SOLVED] Render second scene as texture on cube. What am I missing?

Indeed that does the trick. I had seen another comment from you about this, and was wondering if this was the case.

However, I don’t understand why it shouldn’t work. Shouldn’t we be able to pass a texture onto a map property of a material and it should just work like with any other texture regardless of how we update that texture?

Here’s the example working how you suggested: