Nicolas Alvarez wrote:

>> Nicolas Alvarez <nic### [at] gmailisthebestcom> wrote:
>>> sphere.translate[0]="<5,0,0>"
>>
>>> I think it's a bad idea to allow changing individual transformation 
>>> statements after the object has been created.
>>
>>   There's no such a thing as a "translate" element in a sphere (or in
>> any other object for that matter). Thus it would make no sense to have
>> such an element in the sphere object of the new SDL either.
>>
>>   What should exist is a *function* (member or not) which applies the
>> translation to the sphere (which is a different thing). Calling this
>> function will, naturally apply the subsequent translations properly
>> (as well as other transformations).
>>
>>   (In general all transformations are internally collected into a
>> 4x4 transformation matrix, except when the transformation can be
>> optimized away by eg. transforming the center point of the sphere
>> only. However, there exists no "translate" member variable in the
>> sphere object or any other object.)
>>
> 
> Yep, that was my point. Transforming the object further should *of 
> course* be allowed (complex CSG would become fairly impossible without 
> that!), but having all individual transformation "items" stored in an 
> array and being modifiable seems like a bad idea.
> 
> That was what Patrick Elliot said, and I was replying to:
>  > And you want to adjust the "first" rotation.
>  >
>  > body.arm.rotate(0)="<5,0,0>"
>  >
As warp said, at the moment the individual transformations are not 
stored and there is absolutely no reason in POV4 to do so.
And even if there would be an array of transformations, the textures 
(which is your main problem, I think) would get there own array and 
would not get influenced by such after the fact changes.

BTW in POV there is indeed an interaction of transformations and 
textures that comes from the fact that our textures are 3-dimensional.
I have not much experience with other 3D software but it may be one of 
the things that set POV apart from others. I think that in the context 
of POV4 we should think about how 3D textures influence our scenes and 
how they influence our programming language.

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