Hi Brecht,
So if we used the scene.render.tile_x and tile_y parameters instead of our own, that might make it work?
The reason for the single begin_result call is mainly one of simplicity. The array is initialized at the start of rendering and completed pixels overwrite the initial values as they come in. If rendering is cancelled it seemed easier to load the buffer in one operation rather than try to create another tiling process.
That’s why I 'd really like to get the built in highlighting system working for us. I feel like I’m trying to force a round peg into a square hole when a better solution exists, I just haven’t quite figured out how to use it yet.
So here’s a theory: if scene.render.tile_x (and tile_y) are set to 64 and appleseed renders in 64x64 tiles as well, then the system should work, regardless of exactly how appleseed progresses through those tiles (Hilbert, Spiral, Linear, etc…)?
BTW I appreciate the help
Edit: one other thing. So when the render starts blender splits the image result into a grid based on the tile_x and y size and for highlighting to work it has to do a begin_result on the same places that blender thinks those tiles are? Sorry I’m just trying to understand conceptually how this works.
FYI currently appleseed tells the addon the location of the tile it’s rendering and then that info is used to put the begin_result in the right place.