Hi.
I've a question about the rendering method of POVRay.
When I deide to create a shape, how does program decide the meshing
subdivision of the shape itself?
When I create shapes with other programs (like 3dstudio etc), I can
decide with how many poligons I can create the shape. Even if I use
NURBS models, that depends only by the form, the program convert
shapes to polygons to create the image, and I can work on parameters
that create this transformation.

Have POVRay some command to modify this part of the program itself? Or
it doesn't use polygons in rendering? How POVRay works, generally?


Sorry for my very bad english, but I think that you can understand the
question.


Daniele

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On Fri, 07 Feb 2003 15:26:08 +0100, Jepessen <dan### [at] ciaowebit> wrote:
> Hi.
> I've a question about the rendering method of POVRay.
> When I deide to create a shape, how does program decide the meshing
> subdivision of the shape itself?

It does not make subdivision. Why do you think it does ?

> When I create shapes with other programs (like 3dstudio etc), I can
> decide with how many poligons I can create the shape. Even if I use
> NURBS models, that depends only by the form, the program convert
> shapes to polygons to create the image, and I can work on parameters
> that create this transformation.

The reason why POV-Ray is so accurate is because it usually use exact
equations for "shapes". While triangle and mesh objects are supported things
like cone, sphere, lathe are real curved surfaces.

> Have POVRay some command to modify this part of the program itself?

There is no "this part".

> Or it doesn't use polygons in rendering?

Exactly

> How POVRay works, generally?

It is too general question. You have to be a little more specific.

BTW: there is one case where subdivision is actually used
(http://www.povray.org/documentation/view/167/ - 6.5.2.1 Bicubic Patch) but it
is a very specific case.

ABX

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Jepessen <dan### [at] ciaowebit> wrote:
> When I deide to create a shape, how does program decide the meshing
> subdivision of the shape itself?

  You should urgently read some tutorial about raytracing.

  Raytracing and scanline-rendering are two completely different things.

  For a quick idea, for example if you render a sphere, a raytracer
calculates mathematically the intersection point of a line segment
(the ray) and a mathematical sphere (which is defined simply by a
center point and a radius).

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -

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