I thought a long time how to share my tips about AO the best way (my English isn’t good enough for long posts). But then I’ve figured it out — just another list!
I’m not sure about it, but, in my experience, default Scanline Renderer just isn’t good enough. AO maps require smooth diffused light with reflexes and everything. One of the best for this job is, of course, V-Ray. Very good quality, and at the same time pretty fast.
Most next suggestions will be about V-Ray, sorry. My experience in this stuff is pretty short.
AO should look the same no matter what surface it’s on. Color could be added later, in any image editor with layers and Multiply blending mode.
There is an option in Import, but in case you forgot to uncheck it, fix this color here (press “8”):
Because you can’t stop baking process once it’s started. Yes, 3ds Max is that amazing.
By the way, shortcut for Render To Texture window is “0”.
Just a little bit, not too much (or you can lose some details). For Surface Blur I usually use values 3 and 7.
Open render settings (“F10”), go to the V-Ray tab, decrease Color threshold (appropriate for renderer level of noise) and increase Max subdivs (how much V-Ray will try to get this below required level of noise, roughly speaking):
3ds Max always saves them in sceneassets\images folder, but saved images are broken. It’s a well known bug (again: yes, 3ds Max is that amazing). Also, that’s why you can only render one object at the time.
Basically, you need to bake everything for showroom and don’t look too close how car looks on track. It anyway won’t be occluded by driver, for example (or you have to do some weird magic with CINTURE_OFF/ON nodes, but it’s bad for performance and memory consumption to have two versions of seats).
And don’t forget to hide everything else, so AO will be distributed evenly and won’t ruin everything when wheel will rotate.
This texture is basically shows where is car’s left, right, front and rear sides. Red channel is left side, blue channel is right, green channel is rear side, alpha-channel — front:
Of course, you can just draw it, but also you can use area lights of V-Ray! For example, in my scene I disable VRAY_AO and enable VRAY_LEFT, VRAY_RIGHT and VRAY_BACK, that’s three channels for result texture. After that another render with VRAY_FRONT and result texture is ready!
Unlike txDamageMask, dirt texture still requires some work in image editor. But you can use V-Ray to see where dirt is able to get at all and then go from there. Much easier, if you asked me.
I think it’s enough for now. I very hope this post will help somebody. If you got some questions, please, ask.
Maybe later I’ll make another more detailed post about damages (scratches and normals) and dirt if you interested. Also, of course, you always can use these texture workpieces, there are a lot of stuff that could be helpful.