Am 12.07.2006 um 07:17 schrieb Andreas Raab:
> David Faught wrote:
>> I've been re-reading Takeo Igarashi's SigGraph 1999 paper on Teddy
>> where he describes the inflation method that TPainter 's is based on.
>> TPainter uses a slightly different approach, making use of the
>> of a finished 2D drawing as opposed to Teddy using paint strokes, but
>> the actual inflation method looks similar.
> It is the same.
>> After reading through this a couple of times, it seems to me that a
>> potentially simpler and quicker method might be to build a heightmap
>> by accumulating successive logical ANDs of increasingly offset
>> of the original image, so that heightmap pixels with the greatest
>> planar distance to the edges of the original image would accumulate
>> the highest values. This would take a number of BitBlt's to
>> accomplish, but the offset of each pass could possibly be increased
>> more quickly to reduce the number of passes. Once the heightmap was
>> built, it would then be interpreted into a triangular mesh (somehow)
>> and textured with the original drawing.
>> This is probably not an original thought, has anyone seen this
>> kind of
>> thing implemented somewhere else?
> Only indirectly. I have seen (what I would call) a "dual" version
> of this algorithm for thinning and skeleton generation but not
> exactly what you're describing. It would be interesting to see if
> that has better performance characteristics than the current
> algorithm or if it has other advantages.
I remember a paper about giving a 3D look to 2D cartoon characters
that might work similarly:
Scott F. Johnston: "Lumo: Illumination for Cel Animation"
in Proceedings of Second International Symposium on Non
Photorealistic Animation and Rendering (NPAR 2002)
A method is presented to approximate lighting on 2D
specific problem solved is the incorporation of 2D cel
into live-action scenes, augmenting the existing
method of drawn
"rims and tones" with subtle environmental
image-based tools developed to solve the problem have
photorealistic and non-photorealistic applications.
I think it does not actually build a 3D mesh but IIRC it used image
processing to create a height field.
- Bert -