Some Suggestions About Models and Other Things, Part 3

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!

1. Use proper renderer

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.

2. Make a new scene with proper lights and import cars in it every time you work on something new.


Here is my scene (and some presets for Render To Texture), V-Ray

3. Don’t forget to remove all materials before rendering!

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.

4. And don’t forget to set scene’s ambient color to black!

There is an option in Import, but in case you forgot to uncheck it, fix this color here (press “8”):

5. If you’re not sure, start with 256×256

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”.

6. Use Surface Blur (or it’s analog) in image editor

Just a little bit, not too much (or you can lose some details). For Surface Blur I usually use values 3 and 7.

7. If result is still too noisy, increase render quality

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):

8. Don’t forget to save results manually (and bake only one object at the time)

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.

9. If car has openable doors, open them before baking.

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).

10. Lay wheel with brake disk and caliper horizontally before baking them

And don’t forget to hide everything else, so AO will be distributed evenly and won’t ruin everything when wheel will rotate.

11. You can use V-Ray to help you with txDamageMask texture

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!

12. And also with dirt

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.


4 thoughts on “Some Suggestions About Models and Other Things, Part 3

  1. This tutorial/guide been amazingly useful to me, my car looks alot better now. tnx alot for your dedication, most ppl dont even think about sharing they knowdlage, but u not just did it, u put alot of effort on doing it very clear and very clever!

    Liked by 1 person

  2. Hi, I need to see the car in the interior mirror. Can I do it? I can pay you if you tell me the answer. Sorry my english, i´m spanish. Thanks


    1. Sorry, AC doesn’t allow anything like that, so the only way to do it is to ask Kunos. But apparently they ignore anything like that.


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