Vertex AO for cars

Do you have that one well made mod which however doesn’t have AO baked into it, and UV mapping is not good enough for a quick fix? Or maybe some Kunos car bothers you a bit with its flat look? Great news! Turned out that bakery using NVIDIA’s OptiX Prime is great for baking AO for cars, it’s fast and, in most cases, surprisingly good-looking.

All the advantages are here: it’s zero FPS cost, doesn’t require extra RAM, bakes any mesh, doesn’t care for UV or materials and only affects reflections and ambient lighting. And adapted for cars bakery loads and uses animations, rotates wheels and steering wheel, bakes blurred rims, LODs and low-resoltion cockpit properly.

Notice how steering wheel looks. This way, it wouldn’t look strange when rotated. What I found especially interesting though is that it helps even with some of Kunos cars, especially with interiors of some of them: comparison for Porsche 911 GT3 Cup 2017.

There are a couple of issues though: first of all, it requires GPU supporting CUDA for baking (I’m working on CPU-only option, but while CUDA baking takes seconds, casting more than million rays per second, CPU baking would require tens of minutes). And another problem is that most interiors look way too dark with AO applied. That’s why now Vertex AO patches can also define shader adjustments, increasing ambient brightness by factor of two or so. Plus, now Vertex AO got gamma option, allowing to adjust brightness more carefully for complicated cases. But in general, now, there is a tool allowing to make this change  fully automatically and just in half a minute (I couldn’t bake this car in particular before no matter how I tried, its exterior mesh is just unmappable). Also, of course, it might fail and look buggy with some meshes, but from what I found so far, in almost all cases, it does the job nicely (unlike my silly bakery for tracks, that OptiX-powered monstrosity takes samples not in vertices, but along the surface; it’s basically this tool, but adapted to work with AC models).

Average patch for car with LODs weights about 500 KB, I’m thinking soon CM could download those automatically when necessary, similar to vertex AO patches for tracks.