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Proposal: displacement map baking (almost) for free

Posted: Tue Dec 19, 2006 9:35 pm
by lusque
Sorry for my bad english. :oops: Please take a look at the attached image, hope it make my thoughts understandable.
Image
Now that Blender can Render-Bake Meshes, one simple correction in the Ambient Occlusion algorithm would make possible to Render-Bake a displacement map between two arbitrary meshes.

Ambient Occlusion works by firing a hemisphere (cone) of shadow-rays around from a point on a mesh.
The hemisphere is oriented along the point's normal.
In the AO panel we can specify a "bias factor" wich is the angle (in radians) the sampling hemisphere will be made more narrow.
Currently the bias limit is small (0.5 radians = 28 degrees).

The idea is to augment the bias limit enough to align the sampling rays to the point's normal.
This way the baked ambient occlusion (obtained with "Use Distances" activated) becomes a displacement map.

It would be possible to bake two arbitrary meshes even if they overlap, by baking one displace-map, flipping the mesh normals and then baking a second displace-map. The two maps can then be combined in Photoshop-Gimp or Blender sequencer.
It would be great for baking sculpted meshes into animatable ones with shape keys, bones and such.

What do you think? It is doable? :? If so can someone talk to a developer, it would be grat to have this in the next release!!! :D

Posted: Mon Dec 25, 2006 7:34 pm
by lusque
Bump for this thread! 91 views and no reply! :evil:

Please, don't leave me alone here, it' Christmas! :wink:
What do you think about this thing?

I thought about mailing the bf-committers mailing list, but I don't know if it's the right thing todo. Please, give me directions.

Posted: Tue Dec 26, 2006 8:01 pm
by Caronte
I don't know if your idea is ok at technical level, but anyway I think the coders are to much busy now, because the inminent Blender release ;)

Posted: Tue Jan 02, 2007 2:06 pm
by macouno
lusque, nice idea, but I think there are easier methods, all it would have to do math wise, is follow the face normal from one mesh untill it finds the other.

I expect that high to low poly mesh baking will be added soon, it's all down to when ton has the time for it. It is on his todo list.

Posted: Tue Jan 02, 2007 8:53 pm
by lusque
Caronte and Macouno thank you for your replies, I was starting to feel alone here. :)
I can't tell if this idea is technically ok or if it's the easiest method to bake a displacement map, but if it works:

- there is no need to start coding this thing from scratch, it is enough to modify what is already there ;) (the Ambient Occlusion algorithm)

- I heard that displacement map baking is on the Nicholas Bishop's todo list, but only from a sculpted mesh. Instead by using modified Ambient Occlusion we can bake any mesh into another at will (think of baking a Suzanne on a Cube) (or better: a sculpted mesh on a retopo-ed version of the same mesh but with better edge-loops :twisted: )

So the question is: Is it ok if I mail the bf-committers mailing list, or is better if I wait that a developer find this thread?
If you know a better way to contact a developer, please tell me. Suggestion are more than wellcome.