AO and normal mapping

I have a question regarding baking AO from high-to-low ress model. From what I know it is the same way like baking normals.

->>Unwrap the low ress>>add image>>go in object mode>>select high ress model then select low ress model>> in the render window,under “BAKE” select ‘from high ress’ and ‘selected to active’>>press ‘BAKE’>> save image.

When baking AO you just need to make sure you activate “Ambient Oclussion” and follow the same steps when baking normals is that correct?

Im asking because Im getting this weird artifacts and distortions on the mesh. The normal map is set to UV and under influence is set to Geometry(NORMAL).

Are there any speciffic settings when I add the new texture of the AO. My guess is it should be set to UV and then I draw a blank. Any special settings in the “Influence” window??

The help will be apresiated.

Did you enable the “Normal Map” option in the Image Sampling section of the Textures context? This identifies the image as a tangent space (or other space depending on the selection made) normal map. Under Influence, “Normal” also applies to bump maps (height maps), so you need to specify which type the image is.

AO maps are often applied to the Color channel using Multiply, since their purpose is to imitate the AO shadowing effect, assuming that your AO baked image is a greyscale rendition on a white BG (white has no effect when using Multiply since it multiplies by 1.0)

Yes, its enabled. My normal textures work like a charm. I get into trouble when I start to aply normal+AO+colour texures on a single model.

So when I give the settings to the AO texture, under ‘influence’ I should enable ‘Multiply’?

When applying the image to a particular channel (like Color or Normal or Specular), the mode in which it is blended with whatever else is going on in the material is chosen from the drop down list under the Influence channels listings. The default is Mix, but for some uses, Multiply works better, particularly for shadow plates (like an AO bake) where you have greyscale shadows on a pure white BG. Multiply darkens the diffuse RGB values but doesn’t affect hue or saturation much, making it ideal for shadow effects imo. Darken does something similar but can affect saturation & hue much more.

This explains few things for me. Thank you for the input. Gonna play with it a bit.

Chipmasque, thanks a million man. Finaly figured it out. The good news is I found out where I did wrong. The very good news is my workflow has improved in a matter of hours thanks to your input here. Gonna post in the focused critique my current project soon-ish.

Btw does it matter much, when baking AO, the number of samples and the dimentions of the image that the AO is baked onto?

Once again thanks a lot. You made my day.

Size of the image baked to determines how much fine detail can be recorded in the bake, much as with a painted texture. Samples generally determines what I think of as the “granularity” of the resulting bake, for AO, at least. A higher samples rate gives smoother, less grainy results, but also takes longer.