Christoph Hormann <chr### [at] gmxde> wrote:
> Well - then you would have to be able to give me an example of a POV-Ray 
> shape where you can modify the analytical root solver to support 
> displacement mapping.  As long as you don't i keep my statement that 
> this is not possible (and i am quite sure about this).

  Can you give me an example of how to shear an object without having to
do anything to the root solver? Naturally you can, because POV-Ray supports
exactly that: Instead of modifying the analytical representation of the
object, we modify the rays tested against the object.

  I'm in no way implying it's *easy* or *efficient* to perform displacement
mapping by tracing non-linear rays, I'm just saying it's theoretically
*possible*.

> Is what i write somehow impossible to understand?  If not i have no idea 
> why you post such a reply.

  You said "this is already possible to implement in SDL".
  No, it's not. You can't implement in SDL a dynamic displacement mapping
engine which subdivides triangles on the fly while rendering.

  You can subdivide the entire mesh before rendering and then render it,
but that requires quite a lot of extra memory. My point was that the whole
idea of supporting subdivision in the renderer is that it can perform
memory optimizations which allow almost unlimited subdivision with
limited amount of memory.

-- 
plane{-x+y,-1pigment{bozo color_map{[0rgb x][1rgb x+y]}turbulence 1}}
sphere{0,2pigment{rgbt 1}interior{media{emission 1density{spherical
density_map{[0rgb 0][.5rgb<1,.5>][1rgb 1]}turbulence.9}}}scale
<1,1,3>hollow}text{ttf"timrom""Warp".1,0translate<-1,-.1,2>}//  - Warp -

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