In article <3a6227e4$1@news.povray.org>, "Rune" 
<run### [at] inamecom> wrote:

> Let me see if I understand your storing system.
> There's an array full of bone-id/weight pairs with no duplicates.
> Each element in the array stores exactly one bone-id/weight pair.
> For each vertex in the mesh there's one or several pointers 
> bone-id/weight pairs.
> Is that right?

Close. There is also an array of bones themelves, the bone IDs are just 
indexes for this array. And each vertex has an array of indexes for the 
array containing the bone ID/weight pairs.


> What I don't understand is how it makes sense to store individual 
> weights.
> The weights are *relative to other weights* so storing just one
> bone-id/weight pair at a time makes no sense.
> Or does it? Can you explain?

The weights for each vertex will always total to 1, is that what you 
mean?
The weight value determines the influence of a specific bone, right? So 
it makes sense to pair them up..."xx% of the influence comes from y 
bone". There will be duplicates in this information, especially when 
several vertices belong to one bone and only that bone, so those 
duplicates can be eliminated by making a separate list of data pairs and 
referring to the pairs in that list by ID number.
I'm not really certain what you are asking...each vertex is affected by 
each bone that "owns" it by a specific amount depending on proximity to 
that bone and other bones that "own" it, right? POV would calculate the 
effect of each bone, and add the bone ID and weight to the array for 
that vertex.


> I know! I already mentio- ... Never mind.

Er, ok. :-)


> Anyway, the data would be stored as a part of the scene/include file, 
> just like mesh vertices are, right? But how would the data be 
> generated?
> 
> We agree that fields could initialise the data, but how would this be 
> done?
> External utility? I don't think that's a good idea.

No, it would be done in the parsing stage. The bone and vertex 
information would be parsed in, and the bone fields would be used to 
"fill in" the unspecified weights. The data would then be passed to the 
code that actually moved the vertices, which won't care *how* the data 
was generated. That bit of code (and the one-field code) may be useful 
somewhere else separately, no real reason to make them integral with 
each other. It should also be a little easier to maintain.
From the user's perspective, it just lets them specify everything, 
nothing, or just a few points, while POV automatically computes anything 
they leave out with no extra syntax.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

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