Reduce texture sizes

[franciscoaguirre]

For saving memory.
Right now we are creating all textures with size max_node_pool_size, which is the size the node pool would have if it was dense.
It's not the worst thing if we just had one texture like that, but we have a bunch.

An idea to fix this is to create the node pool texture with this size, then create a new texture with the correct size (now that we know it) and copy the node pool over. We can then create all new textures with this size.

We'd need to be careful with dynamic objects if we do this. We could add a little buffer of extra space to handle them.