3Ds Max: Sub-Objects Texture Baking

Shad0w_Walker

Hi guys.

I've got a problem for a few days now: I' modelled a gun in 3DS max and unwrapped it into 3 pieces (So I have highres maps.)

1: The Sights
2: Pictinyrails & smaller Parts
3: Mainbody + Stock



(I gave them diffierent colors)

Is it possible to bake 3 different meshs within 1 bake? So I define 2 as Sub-Objects and get the shadows of the smaller parts (slingmounts, etc.) on to the larger main body?


I hope you can help me out with that.


Cheers & thanks in advance!

Dan Powell

Honestly I'd recommend keeping the whole gun on a single texture sheet. If you need it to be high resolution then bake it out at 4096 * 4096 - if this is for games in particular then I think anything higher might be unnecessary?

When you bake the Ambient Occlusion/Shadow map for the Larger main body sub-object add all three sections to your Projection Modifier (for baking inside of 3DS Max or XNormal) and it will take into account the shadows cast by every object you list as your high poly inside the Projection modifier.

As a breakdown:

1) Select your low poly "larger main body" object
2) Apply a Projection Modifier to the low poly larger main body
3) Click "Pick" on the Projection modifier and Select the High Poly objects for the Larger main body, the Sight, and the Smaller parts
4) Baking will now take into account all of the objects listed on your Projection Modifier

Eric Chadwick

That's a good workflow. However if you have a high-res model to bake from, you'll want to explode the model to avoid overlaps. Some good tips here from EarthQuake:
http://wiki.polycount.com/wiki/Ambient_occlusion_map#EarthQuake.27s_Baking_Method

Shad0w_Walker

@Dan Powell:

I thought that it would be better for the Engine (UE4) if I bake 3 smaller textures, than 1 big one. I think I will create a large map for the complete body (merge yellow+blue), but I would want to have a better details on the sights, since it's meant to be in a first person view. Also I will have a single map for the magazine, since it's meant to be swappable (with other mags) in the final game.

That would be my future steps, unless you recommend me a different approach.


@Eric Chadwick:

I do have a highres model ready:

[SKETCHFAB]3eb05bfae4574c83a200cc0fc9617dbe[/SKETCHFAB]

I was planning on doing a exploded bake, but for showing my problem I choose a regular picture.
Thank you for your tip anyway


Thanks guys! You were really helpful.


Cheers,
Dominik

Eric Chadwick

If it's in view all the time, then you want as few draw calls as possible. If you have three maps, then that's three materials, which means many draw calls.

If you're doing an exploded bake, you'll want two AO passes, as in EarthQuake's example. The exploded bake won't give you the self-shadowing where the exploded pieces are normally touching each other, so that's the reason for the un-exploded lowpoly AO bake.