I added a new track to Stage 2, Lake Tangle 0. It's a two-lap circuit that winds between the Lake Tangle tracks and their new support pillars. It's technical and requires actual braking, but is signposted and has guardrails.
Improved car stability when bumping walls
Fixed an issue where the car could bottom out and bounce off the track on a concave curve (i.e. a tight turn or the inside of a loop)
Added Lake Tangle 0
Moved Rock Loop II to the Stage 2 difficulty class
Added dynamically generated support pillars to some tracks
Fixed a visual issue with colored tire skids being incorrectly illuminated when the car backfires
Fixed an issue where the car would run its collision stabilization routine after crossing the finish line
Made LODs more aggressive in the Lake Tangle tracks
Performance Note
Ive been seeing some drops to 90FPS in Lake Tangle 0 on highest settings on my computer. This is not great, and I've been looking at ways to improve performance that I may start to implement in future updates.
If you're curious, the track segments aren't being batched properly, and I'm going to try rebuilding the track with longer segments and automatic subdivisions on turns.
Car Physics
The interesting part about the car wall stability and car bottoming out is that they're the same thing, and completely unrelated to what I thought they were before.
I thought it was a problem with the physics parameters on the car's collision hull bouncing off things, so I set its bounciness to 0 and kept a small amount of friction so you couldn't game the tracks by just wallriding the outside guardrail with no loss of speed.
As it turns out, the friction was also causing that bounce behavior. I couldn't tell you why, because it's hard to figure out how high speed objects behave in Unity when interacting with complex shapes (i.e. track meshes), but making its friction 0 fixed the problems. The car can bottom out on loops now and ride the guardrails without any unexpected behavior.
You still do lose speed from riding the guardrails now, though. I just explicitly look at the collision data when it happens and see if it's a collision on the side of the car. If so I subtract a little (framerate-independent) speed.
That's all for now! I'm taking a much-needed vacation this weekend so I'm pushing out the update in the middle of the week to get some early feedback.