Spec & ambient occlusion maps how do you make'em?
polycounter lvl 18
what the best method for creating spec maps & ambient occlusion maps? Is there a science behind it? Is this something that you can render to texture in Max as a starting point?
Any tips or tutorials on making these would be greatly appreciated
Thanks
-Lee
Any tips or tutorials on making these would be greatly appreciated
Thanks
-Lee
Replies
Personally use 2 sources.
1-an actual AO render from Xnormal
It is mostly white everywhere, and dark in the crevices. It is very spread out and subtle.
2-a normalmap >>> "fake AO" conversion done in Crazybump. The differences with the above usual AO bake are :
-Mostly focused on medium and small edge detail,
-Picks up both pits and peaks, uses a 50% grey for everything inbetween.
By combining these two textures you can go quite far, very fast. Spec values will mostly come from a dark ctrl-L pass on that base common texture.
Good luck!
regarding the process: depending on the texture i sometimes use the highpass filter to push the contrast around edges.
pior: do you still use this or a similar technique? http://www.pioroberson.com/tuts/tut_texturing_tricks.htm
I tend to use layer masks for most of my texture work so instead of doing a Levels pass on the diffuse, I'll just make new layers using the same layer masks, fill them with appropriate colours, then duplicate the texture overlays which were used on the diffuse.
Must faster with today's tools!
As for the floaters I did not clean them on that example, but it is really fast to do. A matter of minutes most of the time.
Ok. The crazybump fake AO, do you multiply the spec map on top of the normal map in Photoshop?
A spec map can contain unique details in it, like, say, fingerprints on metal, or footmarks on concrete floors, would show up nicely. But they also need to be considered that the darker it is, the less it'll show up. Also, what I like to do, is use the A channel in my spec map for a gloss map (as mentioned above) for more material definition.
Someone once said that an easier way to see what you spec map will look like is to use it as a certain layer mode in photoshop - dont know if thats true, and I think it was linear dodge mode but i cant remember fully.
This is what I had saved in my notes on previewing spec:
"Place spec map in a layer_set over the diffuse, and set the layer_set to color dodge.
While painting the spec you'll see approximatly how hot that surface will get with specular, then you just set an action to switch the specular layer_set to a pass through, save out specmap, and change it back to dodge to continue working on it."
as opposed to Normal-
'Using Normal blending on a layer set treats all the layers within a set as if they were a single layer that is then blended normally with other layers outside the set.'
I find its easiest to render a skylight pass in Max - this gives you a decent AO pass (I use a mentalray AO as well) that doesn't give you shadows around your floaters as it uses a different calculation method for its shadows. Then I just mask between the two, using whichever gives me a better result.