Seminar displacement

[niklasmennig]

My submission for the ARTRT seminar, based on Thonat et al.'s "Tesselation-Free Displacement Mapping for Raytracing"

Quick guide to this submission:

• most work was done in "traversal/mapping_gpu.art", a CPU version is not provided
• some changes were done on the C++ BVH construction side to account for BVH displacement
• to change the displacement bumpmap, the image path can be edited in "driver/tracer.art"
• recommended testing scenes are "disp_rect", "disp_rect_color" and "disp_rect_light"
• calculation of displacement intensity is kept to a single mapping of uv-coordinates to intensity. As such, it is possible to generate procedural displacement maps rather than using a texture. One such example is provided in "traversal/mapping_gpu.art"

My submission features some changes that are quite far up the pipeline so i suspect some problems might come up trying to merge it with the master branch.
I tried to clean up the code as far as possible but if anything comes up, please feel free to contact me.

Aside from that, thank you very much for this seminar, it was a very cool paper to work on and the implementation process taught me a lot (especially how not to do a lot of things)