Rendering overlapping transparent spheres

Rendering overlapping transparent spheres

Post by Benjamin Z. Goldstee » Fri, 21 Aug 1998 04:00:00



I am rendering several overlapping transparent spheres with POV-Ray, but
I am having trouble with the overlaps.  POV-Ray makes overlapping
portions much darker than the non-overlapping portions.  When three
spheres come together, the overlap is complete black.  Is there any way
around this?

Here is a snippet of my code:

#declare T = texture {  
pigment {color rgbf <1, 0.99, 1, 0.95>}
finish {ambient 0 diffuse 0}

Quote:}

sphere {
<0.8544, 0.6183, -1.999>, 0.345
texture {T}
Quote:}

sphere {
<0.7498, 0.2694, -2.015>, 0.35
texture {T}
Quote:}

sphere {
<0.6019, 0.1679, -1.682>, 0.35
texture {T}

Quote:}

Thanks
--
Benjamin Z. Golds*
Crystallography Program
Oklahoma Medical Research Foundation
405 271 8954 / 405 271 7953 (FAX)
 
 
 

Rendering overlapping transparent spheres

Post by Mikael Carneho » Fri, 21 Aug 1998 04:00:00


The best way to do it is to merge the spheres and then apply -one-
pigment to the merged spheres.

Like this:

merge
{
   sphere{<location>, radius /* No texture*/}
   sphere{<location>, radius /* No texture*/}
   sphere{<location>, radius /* No texture*/}
   // as many as you want
   pigment
   {
       color rgbf<1, 0.99, 1, 0.95>
   }    

Quote:}

or, alternatively:

#declare myshape=merge
{
   sphere{...}
   sphere{...}
   sphere{...}

Quote:}

object
{
   myshape
   texture
   {
      // texture here
   }

Quote:}

- Mikael.

- - - - - - - - - - - - -

Mikael Carneholm

Dep. of Computer Science
H?gskolan i Bor?s, Sweden


http://www.studenter.hb.se/~arch

 
 
 

Rendering overlapping transparent spheres

Post by Dan Connell » Fri, 21 Aug 1998 04:00:00


the problem is you need to reset max_trace_level in global_settings
to something greater than the default value of 5.

Dan


> I am rendering several overlapping transparent spheres with POV-Ray, but
> I am having trouble with the overlaps.  POV-Ray makes overlapping
> portions much darker than the non-overlapping portions.  When three
> spheres come together, the overlap is complete black.  Is there any way
> around this?

> Here is a snippet of my code:

> #declare T = texture {
> pigment {color rgbf <1, 0.99, 1, 0.95>}
> finish {ambient 0 diffuse 0}
> }
> sphere {
> <0.8544, 0.6183, -1.999>, 0.345
> texture {T}
> }
> sphere {
> <0.7498, 0.2694, -2.015>, 0.35
> texture {T}
> }
> sphere {
> <0.6019, 0.1679, -1.682>, 0.35
> texture {T}
> }

> Thanks
> --
> Benjamin Z. Golds*
> Crystallography Program
> Oklahoma Medical Research Foundation
> 405 271 8954 / 405 271 7953 (FAX)

--
Motorola Semiconductor
 
 
 

Rendering overlapping transparent spheres

Post by Sjann Johns » Wed, 26 Aug 1998 04:00:00


On Thu, 20 Aug 1998 11:36:04 -0500, "Benjamin Z. Golds*"


>I am rendering several overlapping transparent spheres with POV-Ray, but
>I am having trouble with the overlaps.  POV-Ray makes overlapping
>portions much darker than the non-overlapping portions.  When three
>spheres come together, the overlap is complete black.

    This sounds like the infamous max_trace_level problem. Increase the
value of max_trace_level in the global_settings {...}.
    This is one of those non-intuitive questions that should be in the FAQ.
(Maybe it is.)

"Thank god for wild angels."

 
 
 

Rendering overlapping transparent spheres

Post by Dirk Prang » Fri, 28 Aug 1998 04:00:00



> I am rendering several overlapping transparent spheres with POV-Ray, but
> I am having trouble with the overlaps.  POV-Ray makes overlapping
> portions much darker than the non-overlapping portions.  When three
> spheres come together, the overlap is complete black.  Is there any way
> around this?

> Here is a snippet of my code:

> #declare T = texture {
> pigment {color rgbf <1, 0.99, 1, 0.95>}
> finish {ambient 0 diffuse 0}
> }
> sphere {
> <0.8544, 0.6183, -1.999>, 0.345
> texture {T}
> }
> sphere {
> <0.7498, 0.2694, -2.015>, 0.35
> texture {T}
> }
> sphere {
> <0.6019, 0.1679, -1.682>, 0.35
> texture {T}
> }

> Thanks
> --
> Benjamin Z. Golds*
> Crystallography Program
> Oklahoma Medical Research Foundation
> 405 271 8954 / 405 271 7953 (FAX)

  If the spheres overlap, I think you should merge them and apply the
texture afterwards.

Dirk

 
 
 

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