Nice scene, thanks for sharing!
The two most important things to optimize the size of the scene and the baking time are:
- Currently your scene has more than 6M triangles, so it requires rather a powerful graphics card to achieve good frame rate (especially in the edit mode). To decrease the number of triangles you can replace high-poly objects with low-poly alternatives. The list of objects in the Objects tab will help you to identify the most complex objects, because it is sorted by the triangle count (at each hierarchy level), and it shows the triangle count together with the number of instances of the object. For example:
- Each lavenderer bush has 140k triangles, and there are 20 bushes, which gives a total of 2,8M triangles.
- Each curtain set on the upper floor has 80k triangles and there are 8 such sets, which gives a total of 640k triangles.
- Use low Custom lightmap resolution (eg. 10) for the terrain around the building, and perhaps also for the vegatation on the terrain. Currently only the wall enclosing the terrain has custom lightmap resolution. If you put all these “terrain objects” in one SketchUp group, you would be able to set the custom lightmap resolution for the whole group with one setting.