Proposal: displacement map baking (almost) for free

Blender's renderer and external renderer export

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lusque
Posts: 11
Joined: Wed Oct 16, 2002 9:53 am

Proposal: displacement map baking (almost) for free

Post 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

lusque
Posts: 11
Joined: Wed Oct 16, 2002 9:53 am

Post 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.

Caronte
Posts: 76
Joined: Wed Oct 16, 2002 12:53 am
Location: Valencia-Spain-Europe

Post 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 ;)
Caronte.
"Some Day, All Will Be Digital"
http://www.nicodigital.com

macouno
Posts: 0
Joined: Tue Nov 18, 2003 3:37 am

Post 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.

lusque
Posts: 11
Joined: Wed Oct 16, 2002 9:53 am

Post 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.

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