Working on file converter, I am importing vertex colors from FBX,
but cant figure out why POV-Ray rendering is so much different from
ZBrush. Maybe there is a way to control color distribution and
smoothness ?

Please find images and scene in attachment.
-- 
YB

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Attachments:
Download 'cube_vc.inc.txt' (2 KB) Download 'scene.png' (29 KB) Download 'scene.pov.txt' (3 KB) Download 'zb.png' (402 KB)

Preview of image 'scene.png'

Preview of image 'zb.png'

yesbird wrote:
> Working on file converter, I am importing vertex colors from FBX,
> but cant figure out why POV-Ray rendering is so much different from
> ZBrush. Maybe there is a way to control color distribution and
> smoothness ?
>
> Please find images and scene in attachment.
> --
> YB

You might not want to color by vertex.
Maybe color the entire cube with a gradient and use blend_mode.

https://wiki.povray.org/content/Reference:Pigment_Map

That's all I have - for the moment.

- BW

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> yesbird wrote:
> > Working on file converter, I am importing vertex colors from FBX,
> > but cant figure out why POV-Ray rendering is so much different from
> > ZBrush. Maybe there is a way to control color distribution and
> > smoothness ?
> >
> > Please find images and scene in attachment.
> > --
> > YB
>
> You might not want to color by vertex.
> Maybe color the entire cube with a gradient and use blend_mode.
>
> https://wiki.povray.org/content/Reference:Pigment_Map
>
> That's all I have - for the moment.
>
> - BW

#version 3.8;

global_settings {assumed_gamma 1.0}

#include "functions.inc"

camera {
 location <0, 0, -20>
 look_at <0, 0, 0>
 right x*image_width/image_height
 up y
 sky y
}

sky_sphere {pigment {rgb 1}}

light_source {<0, 50, -50> rgb 1}


box {-5, 5
 pigment {
  gradient x
  pigment_map {
   blend_mode 0 // or 3
   [0, rgb y]
   [0.5, rgb 1]
   [1, rgb z]
  }
  scale sqrt (200)
  translate x*sqrt (200)/2
  rotate z*45
 }
}

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Attachments:
Download 'yesbirdcolorcube.png' (29 KB)

Preview of image 'yesbirdcolorcube.png'

"Bald Eagle" <cre### [at] netscapenet> wrote:

> That's all I have - for the moment.

OK - I think that also maybe the colors for your vertices are done wrong.

Make your top left and bottom right four vertices white
top right two vertices blue
bottom left two vertices green


#declare model = mesh2 {
vertex_vectors {
  8,
  <-0.20000000298023224,0.20000000298023224,0.20000000298023224>, // 0 Left Top
Rear
  <0.20000000298023224,0.20000000298023224,0.20000000298023224>,  // 1 Right Top
Rear
  <0.20000000298023224,0.20000000298023224,-0.20000000298023224>, // 2 Right Top
Front
  <-0.20000000298023224,0.20000000298023224,-0.20000000298023224>, // 3 Left Top
Front
  <-0.20000000298023224,-0.20000000298023224,0.20000000298023224>, // 4 Left
Bottom Rear
  <0.20000000298023224,-0.20000000298023224,0.20000000298023224>, // 5 Right
Bottom Rear
  <0.20000000298023224,-0.20000000298023224,-0.20000000298023224>, // 6 Right
Bottom Front
  <-0.20000000298023224,-0.20000000298023224,-0.20000000298023224>, // 7 Left
Bottom Front
  }

texture_list {
 8,
 texture{pigment{rgb 1}}
 texture{pigment{rgb z}}
 texture{pigment{rgb z}}
 texture{pigment{rgb 1}}
 texture{pigment{rgb y}}
 texture{pigment{rgb 1}}
 texture{pigment{rgb 1}}
 texture{pigment{rgb y}}
}

face_indices {
  12,
  <0,1,2>, 0,1,2,
  <2,3,0>, 2,3,0,
  <4,5,1>, 4,5,1,
  <1,0,4>, 1,0,4,
  <5,6,2>, 5,6,2,
  <2,1,5>, 2,1,5,
  <6,7,3>, 6,7,3,
  <3,2,6>, 3,2,6,
  <7,4,0>, 7,4,0,
  <0,3,7>, 0,3,7,
  <7,6,5>, 7,6,5,
  <5,4,7>, 5,4,7,
  }
}

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Attachments:
Download 'cube_scene.png' (23 KB)

Preview of image 'cube_scene.png'

On 30/09/2025 04:21, Bald Eagle wrote:
> You might not want to color by vertex.
> ...

Thanks for the suggestion, but I would like to keep vertex colors for
more complicated paintings, then trivial gradients.

Increasing number of polygons solves this problem and it looks fine
now, but don't you know how to make colors more saturated ?

Please, look at attachments.
-- 
YB

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Attachments:
Download 'scene.png' (42 KB) Download 'scene.pov.txt' (4 KB) Download 'model.zip' (2003 KB)

Preview of image 'scene.png'

On 30/09/2025 04:54, Bald Eagle wrote:
> OK - I think that also maybe the colors for your vertices are done wrong.
> 
> Make your top left and bottom right four vertices white
> top right two vertices blue
> bottom left two vertices green
> 
Thanks, it looks much better !
I've checked it already, but see now any errors, will try again.
-- 
YB

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On 30/09/2025 04:54, Bald Eagle wrote:
> 
> OK - I think that also maybe the colors for your vertices are done wrong.
> 

No, now I see that the problem is not in POV-Ray - 3js renders this
cube the same way (attached). Sorry for inconvenience.
-- 
YB

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Attachments:
Download 'cube.png' (420 KB)

Preview of image 'cube.png'