12 septiembre 2015

Removing ambient occlusion from photo-scanned subjects

This is a simple idea I came up  last night. I was making a little stone that would be used rotated in every axis. Then I figured out that the ambient lighting of the original capture won't match with the scene. This was the subject:


So the idea was to convert this diffuse into an albedo. The method consist on emulating the scenario to get a simulation of the original lighting conditions I had there. Then I will use the inverse of that result to brighten the original captured diffuse.
You see there the lighting came from every direction from the clouds and a little percent of it came from the ground (typical hemisphere lighting).
So the scene can be emulated like this:


Here is the resulting ambient occlusion:


Captured albedo. Notice it matches perfectly with the emulated AO

 

Now, I inverted the AO and blended it as "Linear Light" with opacity 50%. Other blending modes may be tested; "Lighten" seems to work pretty nicely too.

I can now bake a new AO without any other geometry than the model:


And finally, the diffuse texture after the surgery session:


1 comentario:

  1. Hi, really interesting, how did you make the light simulation ? with 3dsmax, c4d, blender, maya ???? do you make it with the high-def mesh or with a decimated one ?

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