VDrift Graphical Upgrades

[joevenzon]

i'll need to check out the art repo. do i have commit access to that one?

Yes. Any .blend files should go in there instead of in the data repo.

[zimluura]

Forget about the separate mesh the glow could be done using an additive texture.

i was totally thinking the next thing would be a separate rotor mesh. a separate mesh allows geometric scaling of the mesh independent of the wheel's edge. this is sort of essential to accurately generate a mesh for lots of rear wheel rotors, which are usually smaller than the front ones. also allows us to swap textures when upgrading to ceramic rotors which would be cool too.

thinking we'll need to figure out, at some point, wheel offset and caliper clearance.

Right now we have a material texture(surface properties), a diffuse texture with transparency. Object color with alpha to adjust whole object transparency (and color?). There is the diffuse color, vertex color blending hack. And then there are up to two additive maps that are not influenced by lighting.

i've been thinking a little bit about materials. i wonder how exactly they did tint maps in the neverwinter nights games. i've never been a big fan of the additive maps for lights. i've always felt billboards are the way to go there.

i have, for a while, been thinking that some kind of micro textures would be good. mostly for cars with metallic/pearl-coats, and also specular highlights on roads. like a setup where each micro texture is a tile-able 64x64 texture (maybe grayscale) it gets applied as well as the regular texture but the tmu that handles the micro coordinates multiplies them all by 10 or 100 or something.

[NaN]

micro textures would be good. mostly for cars with metallic/pearl-coats, and also specular highlights on roads.

This is what the misc1 textures are meant for. They describe surface glossiness and reflectivity (r and g channel). There has been some discussion to replace the current lighting equation with a more generic one. http://vdrift.net/Forum/viewtopic.php?t=...c&start=15

a separate mesh allows geometric scaling of the mesh independent of the wheel's edge. this is sort of essential to accurately generate a mesh for lots of rear wheel rotors, which are usually smaller than the front ones.

I see. But I think the generated geometry(tire, rim, brake disc) has already the correct scale at creation(due to given parameters). Front and rear wheels have different meshes. We don't share them atm.

[zimluura]

the misc textures don't really let us up-scale the uv coordinates to get sparkles yet. we can get them, but only if we have a really really big texture. if there is some option for a texture that gets applied with all the texture coordinates scaled x10 or x100 in the shader then we can have smaller graphics card footprint (and faster loading) and still get a really sparkle-y metallic coat.

we might be thinking the same thing on the brake disc: i thought you were saying that that there should not be a mesh gen function to make one because it should be part of the wheel_edge mesh.

[NaN]

but only if we have a really really big texture

Hm, even with 2048px textures for the cars? But the resolution of the asphalt misc texture should be OK?

we might be thinking the same thing on the brake disc

Agree

[zimluura]

i think even with 2048x2048 base textures we'd still want something higher res (effectively) for metallic/pearl paint. i googled for some examples.
http://gallery.viperclub.org/data/500/09bb.jpg
http://media.photobucket.com/image/pearl...C01375.jpg

i don't recall it being very hard to write a shader that multiplies one of the applied texture's coordinates. for something like a metallic texture, something that you don't always see the full effect until you get close, i think a low-res, tile-able noise texture would be the way to go. probably should make the noise textures shared so they can be applied as paint jobs.

for the roads, well, when i go walking around my neighborhood in the ~noon sun. i usually see just a few very_small sparkles. to emulate that, i think something tile-able too, but since the little glints are fewer we might need to do something (else) to get around the tile pattern that might show up. as the sun sinks the game probably changes dramatically. haven't studied this enough to even form an opinion on emulating it yet.

google-ing "time-lapse sunset over road" videos hasn't been too fruitful either. lens flair usually washes out what i want to see.
http://www.youtube.com/watch?v=xsm_YzTldls
this sorta has something around 1:08 - but it's so short it might as well be a still.

still images gives us much more nifty stuff:
http://www.blindoptic.com/mullen/uploade...765110.jpg
http://www.worldofstock.com/slides/DEC1630.jpg

[joevenzon]

Those are usually referred to as "detail textures," but they haven't been used for a while because the type of small detail you usually want are variations in the lighting due to surface normal variation -- normal mapping is used instead. Adding support for normal maps wouldn't be too tough. We could do detail normal mapping too, although I'm not sure if it's needed to get the desired effect.

I've been fiddling with deferred rendering and the BRDF on page 2 of this thread. Here are some rambling thoughts about it. One issue is that with deferred rendering you must minimize the number of material properties that need to go to the lighting pass. The BRDF I mentioned earlier looks good and requires an RGB for the specular reflection value plus a float for the roughness/shinyness. Normals go to the lighting pass per fragment so we could get fancy with normal maps without any problems. Unrelated -- I'm not sure if we'll need a double-lobed BRDF or not for car paint yet. We could sum multiple BRDFs based on multiple shinyness values.

[portets]

the deferred rendering looks interesting. i like it.

hey joe, i have a simple street texture and a normal map for it if you feel like playing with normal mapping.

https://docs.google.com/uc?id=0ByBA2iQHj...load&hl=en

it's very simple. i haven't drawn cracks or anything like that yet. it looks like freshly laid tarmac. i had to reduce the size to 2048x2048 to reduce upload time, but it should still look pretty detailed. it's really simple though

[joevenzon]

Hey, cool! Thanks. It'll be a little bit before I get around to normal maps because I'll need to upload the tangent vector for models to be able to work in tangent space, and currently don't have that set up, but when I do it'll be nice to have a texture ready to go. It looks like it'll be a drop-in replacement for the road* textures in rouen.