Baking Cakes

First of all wanted to share that I finished uvmapping and rendering out all the Ambient Occlusion (except for wheels). Now that that's done I can move onto the nice part: sculpting and texturing :) Here are my labours:

Could have used more sampling but i think this will be enough.

Secondly I thought I'd share exactly the method I used to do it as it isnt that straight forward. This is a little step-by-step tutorial to help people improve their models and textures. N.B.: The object that receives the baked occlusion texture has to be ALREADY UVMapped so that the UV face coordinates DO NOT intersect. So the cube in this tutorial has a UVWUnwrap modifier on it and its uvw coordinates have been manipulated. Also this tutorial is for 3dsmax with MentalRay.
Here is the layout:

I usually like to assign a grey standard materials and change the wireframe color to black. Just personal preference. just make sure that the cube has a seperate material from the other objects:

Open up the Environment... dialog by pressing 8 on the keyboard or Render>Environment... . Change the "Ambient" Color to white:

Close the window and select the cube. Now open the "Render To Texture" dialog by pressing 0 (zero) or in the Render menu. Scroll down a little and click the "Add" button. A popup should ask you what you want to bake so choose "Ambient Occlusion (MR)". Probably a goot time to mention that you have to have MentalRay assigned as your primary renderer. Press "Add Element".

Choose a folder to save the file to and press "Render" and voila:


To get the picture exactly like my previous one, go back to the cube material and assign the texture you just saved to the diffuse map slot and turn its viewport visibility (blue/white box in the Material Editor).

But hang on there's more! You can tweak how the AO looks like in your bake...to a certain extent. You can choose the texture size. But more useful are the AO controls. In the next screengrab I increased the spread value to show what it does:

CLICK TO MAKE BIGGER

Essentially what it did was take the calculated shadow (or more correctly the samples) and started stretching them over the specified spread. A note on samples: the higher the sample value, the higher the cuality of the AO pass, but be ware...render times will suffer above 256 for large textures.

In the below screengrab you can see the effects of Max Distance value:

CLICK TO MAKE BIGGER

Basically it is the distance at which it will stop calculating the shadow from the contact edge. So the smaller the value the smaller the shadow (BUT not 0.0!! a value of null will mean there is no cutoff!). Basically you should tweak these values for best results according to your needs.

I hope that was clear :).

Cheers!