Rune <run### [at] inamecom> wrote:
> AFAIK meshes, bicubic patches and perhaps iso-surfaces can be transformed
> nonlinearly. Or they could if there was functions in POV-ray that was
> designed to do this...
>
> I suggest that we begin to think of the possibilities of implementing such
> functions. I personally believe that it could improve POV-Ray
significantly
> in some of the areas where it is currently not as powerful as many other
> renderers.
>
> To make such functions useable it would probably be necessary to implement
> several different kinds of those nonlinearly transformations. They could
all
> be contained into a statement such as deform {} or something.
>
> One type of deform could be one that deforms dependent on warps:
>
> deform {
>    warp {...}
> }
>
> As you can sure imagine, this alone would be a very powerful and general
way
> of deforming the supported object.
>
> But more complicated ways of deforming may be useful. I have thought of a
> feature that would deform objects by several user-specified regular
> transforms, each weighted by a 3D field in space. I believe this could be
> used for many things. For example it could be used to make a kind of bone
> structure. One part of a mesh body could be enclosed by one field which
> would be transformed by one linear transform. Another part of the body
would
> by due to another field be transformed by another linear transform. The
> 3D-fields could be defined by patterns, which would be very flexible, but
> probably also rather difficult to master and somewhat slow, or they could
be
> controlled in a way similar to blobs, which would be less flexible, but
> surely easier to understand, and probably faster. Possible syntax:
>
> deform {
>    field_transform {
>       sphere {
>          location, radius, strength,
>          transformations (of the field)
>          apply_transform transform_id (of the mother object, such as mesh)
>       }
>       cylinder { (like sphere, but with end1, end2 instead of location) }
>       ...
>    }
> }
>
> alternative way:
>
> deform {
>    field_transform {
>       field {pattern_id, transform_id}
>       field {pattern_id, transform_id}
>       ...
>    }
> }
>
> The pattern way of field_deform could be used with blob_pattern to achieve
> same functionality I guess, but it would probably still be slower.
>
> Other deform types could possible be made too. What do you think of the
> whole idea?

If you would like to experiment a little with mesh and patch deformations,
without modifying the POV code just yet, perhaps you should look at the
Compressed Mesh macro file in conjunction with Warp's Mesh Compressor:

   http://www.geocities.com/ccolefax

The Compressor and Macros combined give you access to the vertices of meshes
(including bicubic patch models), and you are free to warp these at will.
Using various MegaPOV features (such as eval_pigment), you could even try
out ideas like your pattern warps.

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