An amazing job XL2!
From what I see of the image that you have shared, and the theory of the tutorial. It is a technique very oriented to closed scenarios, with rooms and with the basic primitive of the triangle.
I understand that it may be difficult for you to implement the BSP tree for both SS, primitive and open levels by levels like this of the Sonic.
I can think of a few suggestions, to see what you think:
1) Try to create, or force, the triangle to a quad of the SS. In order to facilitate a replacement with a predefined texture, it works better. And avoid the overdraw of using forced triangles in SS.
2) Search that the geometry designs are designed to create more square divisions. For example, the plant in X, which is 45º above the quad of the ground, are divisions that seek to follow this angle. If this plant were at 90 degrees, the divisions would be more square.
3) For the theme of textures that look bad. I see complicated that you can automate this. That is, automatically cut the textures, so that new textures are created small, more adjusted to the division. Of course all this results in using more space of VDP1 VRAM.
4) I do not know if it would be possible to use RockinB's UV flat mapping code, which I found from my tests quite quickly. On these triangular primitives, to avoid generating new textures, although you will still have the problem of redrawing by deformation.
5) Use the triangle with a mask as an alternative to forcing triangles. But I do not know how you can translate the coordinates of the vertices to this "triangle", so as not to load the transformations engine or the BSP motor itself.
6) Finally, I do not know if you would use the LOD by distance. Perhaps these zones divided into more "ugly" triangles are not seen with the closest LOD.
Great work and encourage!
I continue with my research and analysis work for my entries. On the other hand I hope to finish my 3D engine proposal soon and share it with everyone.
Regards,
