In article <3F193F21.DC20B444@gmx.de>,
 Christoph Hormann <chr### [at] gmxde> wrote:

> "In what way is the blob2 better than other solutions (existing blob shape
> and isosurface blobbing solutions) and how does the patch accomplish
> this."

Existing blob shape: the blob2 object is more flexible (having more 
component types), and uses a different falloff function that gives 
smoother blobs. Look at the pictures I've put up demonstrating the 
difference. The old blob looks like lumps covered in goo, the blob2 
looks like it's just the goo.

Isosurfaces: the main advantage is that it is faster. It uses 
optimizations that can't be done in even a hard-coded isosurface 
function. For example, it collects the components that influence a ray, 
and uses only those when searching for the intersection. If you have a 
blob2 with hundreds of components, but only two components affect the 
current intersection being tested, only those two components will get 
evaluated.

In addition to this, the blob2 uses this list to automatically figure 
out the beginning and end of the interval to check for intersections. 
Not only do you not have to specify a container, the blob2 algorithm 
comes up with more accurate bounds than you could specify anyway, using 
the bounding shapes of individual components.

It also seems to give smoother results with low accuracy. Artifacts do 
show up, but the isosurface shape gives a more visible "stepping". This 
may just be an illusion, a bug with the isosurface, or something I'm 
doing with blob2 that the isosurface doesn't. It might be an effect of 
the interval checking mentioned above, it is like having a more 
irregular container.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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