1. With the actual default algorithm, the photo is divided in several parts, each part is assigned to a CPU thread. But some parts are easy to compute and some others take a very long time. So, if there is an easy way to detect which parts are hard to compute, then I suggest to compute them first, in order to have a better use of threads, because I noticed that at the end of the rendering, I often have a few threads working on difficult parts, and the other threads doing nothing.

If it is possible to compute difficult parts first, maybe it could be an option in the renderer settings.

2. I don't know if it is possible, and I don't have any knowledge in 3D rendering, but it seems that only specular light depends of the point of view. So if someone needs to take a lot of photos, maybe it is possible to compute ambient and diffuse light once for the whole scene, and then compute only the specular for each point of view ?

3. Maybe a pause/resume function for simple and multiple photo rendering could be useful to some users.

4. As I'm illuminating the rooms through curtains, I managed to create some curtain models made of strings, instead of transparent surfaces.

When I illuminate a room placing a light panel behind these string curtains, the lighting of the room and the shadows are very ugly, as shown by the picture in the following forum post