In documentation there is an example

//////////////////////////////////////////////////////////////////////////////
 global_settings
 { photons
   { count 20000
     media 100
   }
 }
 camera { location <14.9, 1, -8> look_at -z angle 70 }
 light_source { <10,100,150>, 1 }
 background { rgb <0.3, 0.6, 0.9> }

 // A dim light source inside the room which does not
 // interact with media so that we can see the room:
 light_source { <14, -5, 2>, 0.5 media_interaction off }

 // Room
 union
 { difference
   { box { <-11, -7, -11>, <16, 7, 10.5> }
     box { <-10, -6, -10>, <15, 6, 10> }
     box { <-4, -2, 9.9>, <2, 3, 10.6> }
   }
   box { <-1.25, -2, 10>, <-0.75, 3, 10.5> }
   box { <-4, 0.25, 10>, <2, 0.75, 10.5> }
   pigment { rgb 1 }
 }
 // Reflective floor:
 box
 { <-10, -5.99, -10>, <15, -6, 10>
   pigment { rgb 1 }
   finish { reflection <0.5, 0.4, 0.2> }
   photons { target reflection on }
 }
 // Scattering media box:
 box
 { <-5, -6.5, -10.5>, <3, 6.5, 10.25>
   pigment { rgbt 1 } hollow
    photons { pass_through }
    interior
    { media
       { scattering { 1, 0.07 extinction 0.01 }
       samples 30
       }
    }
 }
///////////////////////////////////////////////////////////////////////////////

Render time: 11 m
I created a similar scene in Blender, using mesh2

///////////////////////////////////////////////////////////////////////////////

//----------------------------------------------
//--Export to Povray from Blender--
//----------------------------------------------

#version 3.7;
#include "functions.inc"


global_settings {

    photons {
        count 20000
        media 100
    }

}

background {rgbt<0.0509, 0.0509, 0.0509, 0>}




//--Material Definitions--

#declare T_Map_Cube = pigment {color rgb<0,0,0>}
#declare Texture_2_Cube = pigment {color rgb<0,0,0>}
#declare T_Map_Cube_001 = pigment {color rgb<0,0,0>}
#declare Texture_2_Cube_001 = pigment {color rgb<0,0,0>}
#declare T_Map_Plane = pigment {color rgb<0,0,0>}
#declare Texture_2_Plane = pigment {color rgb<0,0,0>}
#declare T_Map_Plane_001 = pigment {color rgb<0,0,0>}
#declare Texture_2_Plane_001 = pigment {color rgb<0,0,0>}
#declare shader_Material = finish {  //translation of spec and mir levels for
when no map influences them
    brilliance 2
    specular 0
    roughness 0.0001
    diffuse 0.8 0
    ambient <0, 0, 0>
    emission 0
    conserve_energy
}

#declare Texture_1_Cube = texture {pigment {color rgbft<0.8,0.8,0.8,0,0>}
finish{shader_Material}}
#declare shader_Material_004 = finish {  //translation of spec and mir levels
for when no map influences them
    diffuse 0.8
    phong 70.0
}

#declare Texture_1_Cube_001 = texture {pigment {color rgbt 1}}
#declare shader_Material_002 = finish {  //translation of spec and mir levels
for when no map influences them
    brilliance 2
    specular 0.5
    roughness 0.01
    diffuse 0.8 0
    ambient <0, 0, 0>
    emission 0
    conserve_energy
    reflection {
        0.287        metallic 0    }
}

#declare Texture_1_Plane = texture {pigment {color rgbft<0.8,0.6416,0.1664,0,0>}
finish{shader_Material_002}}
#declare shader_Material_003 = finish {  //translation of spec and mir levels
for when no map influences them
    brilliance 2
    specular 0
    roughness 0.0001
    diffuse 1 0
    ambient <0, 0, 0>
    emission 1.76
    conserve_energy
}

#declare Texture_1_Plane_001 = texture {pigment {color rgbft<0.8,0.8,0.8,0,0>}
finish{shader_Material_003}}
#declare T_Mix_1_Cube = Texture_1_Cube
#declare T_Mix_2_Cube = Texture_2_Cube
#declare T_Mix_1_Cube_001 = Texture_1_Cube_001
#declare T_Mix_2_Cube_001 = Texture_2_Cube_001
#declare T_Mix_1_Plane = Texture_1_Plane
#declare T_Mix_2_Plane = Texture_2_Plane
#declare T_Mix_1_Plane_001 = Texture_1_Plane_001
#declare T_Mix_2_Plane_001 = Texture_2_Plane_001

//--Mesh objects--

#declare Cube_001 =
mesh2 {
    vertex_vectors {
        8,
        <0.958881, 1.522728, -0.958881>,
        <-0.958881, 1.522728, -0.958881>,
        <-0.958881, -2.315529, -0.958881>,
        <0.958881, -2.315529, -0.958881>,
        <0.958882, 1.522728, 0.958881>,
        <0.958881, -2.315530, 0.958881>,
        <-0.958882, -2.315529, 0.958881>,
        <-0.958881, 1.522728, 0.958881>
    }
    normal_vectors {
        6,
        <0.000000, 0.000000, -1.000000>,
        <-0.000000, -1.000000, -0.000000>,
        <1.000000, -0.000000, 0.000000>,
        <-1.000000, 0.000000, -0.000000>,
        <0.000000, 1.000000, 0.000000>,
        <0.000000, -0.000000, 1.000000>
    }
    texture_list{1, texture { pigment_pattern { T_Map_Cube_001 }
            texture_map {
                [0.0 T_Mix_1_Cube_001]
                [1.0 T_Mix_2_Cube_001]
    }}}
    face_indices {
        12,
        <0,1,2>, 0,0,0,
        <0,2,3>, 0,0,0,
        <4,5,6>, 0,0,0,
        <4,6,7>, 0,0,0,
        <3,2,6>, 0,0,0,
        <3,6,5>, 0,0,0,
        <2,1,7>, 0,0,0,
        <2,7,6>, 0,0,0,
        <1,0,4>, 0,0,0,
        <1,4,7>, 0,0,0,
        <4,0,3>, 0,0,0,
        <4,3,5>, 0,0,0
    }
    normal_indices {
        12,
        <5,5,5>,
        <5,5,5>,
        <0,0,0>,
        <0,0,0>,
        <4,4,4>,
        <4,4,4>,
        <2,2,2>,
        <2,2,2>,
        <1,1,1>,
        <1,1,1>,
        <3,3,3>,
        <3,3,3>
    }
    hollow
    interior {
         media {
              scattering { 1,
                  <0.08353, 0.08353, 0.08353>
               extinction 4.871 }
              samples 256
        }
    }
    photons{ pass_through }

}

#declare Plane_001 =
mesh2 {
    vertex_vectors {
        4,
        <1.000000, -1.000000, 0.000000>,
        <-1.000000, -1.000000, 0.000000>,
        <1.000000, 1.000000, 0.000000>,
        <-1.000000, 1.000000, 0.000000>
    }
    normal_vectors {
        1,
        <0.000000, 0.000000, 1.000000>
    }
    texture_list{1, texture { pigment_pattern { T_Map_Plane_001 }
            texture_map {
                [0.0 T_Mix_1_Plane_001]
                [1.0 T_Mix_2_Plane_001]
    }}}
    face_indices {
        2,
        <1,0,2>, 0,0,0,
        <1,2,3>, 0,0,0
    }
    normal_indices {
        2,
        <0,0,0>,
        <0,0,0>
    }
    interior {
        ior 1.000000
        caustics 0.1
    }
    photons{    }

}

#declare Plane =
mesh2 {
    vertex_vectors {
        4,
        <1.000000, -1.000000, 0.000000>,
        <-1.000000, -1.000000, 0.000000>,
        <1.000000, 1.000000, 0.000000>,
        <-1.000000, 1.000000, 0.000000>
    }
    normal_vectors {
        1,
        <0.000000, 0.000000, 1.000000>
    }
    texture_list{1, texture { pigment_pattern { T_Map_Plane }
            texture_map {
                [0.0 T_Mix_1_Plane]
                [1.0 T_Mix_2_Plane]
    }}}
    face_indices {
        2,
        <1,0,2>, 0,0,0,
        <1,2,3>, 0,0,0
    }
    normal_indices {
        2,
        <0,0,0>,
        <0,0,0>
    }
    interior {
        ior 1.072000
    }
    photons{
        target 1
        reflection on
    }

}

#declare Cube =
mesh2 {
    vertex_vectors {
        24,
        <1.000000, 1.000000, -1.000000>,
        <1.000000, -2.356648, -1.000000>,
        <-1.000000, -2.356648, -1.000000>,
        <-1.000000, 1.000000, -1.000000>,
        <1.000000, 0.999999, 1.000000>,
        <0.999999, -2.356648, 1.000000>,
        <-1.000000, -2.356647, 1.000000>,
        <-1.000000, 1.000000, 1.000000>,
        <1.000000, 0.242933, -0.270760>,
        <1.000000, -0.242933, -0.270760>,
        <1.000000, 0.242933, 0.556969>,
        <1.000000, -0.242933, 0.556969>,
        <0.958881, 0.958881, -0.958881>,
        <-0.958881, 0.958882, -0.958881>,
        <-0.958881, -2.315529, -0.958881>,
        <0.958881, -2.315529, -0.958881>,
        <0.958882, 0.958881, 0.958881>,
        <0.958881, -2.315530, 0.958881>,
        <-0.958882, -2.315529, 0.958881>,
        <-0.958881, 0.958881, 0.958881>,
        <0.958881, 0.242933, -0.270760>,
        <0.958881, 0.242933, 0.556969>,
        <0.958881, -0.242933, -0.270760>,
        <0.958881, -0.242933, 0.556969>
    }
    normal_vectors {
        20,
        <-0.000000, -1.000000, -0.000000>,
        <1.000000, -0.000000, -0.000000>,
        <-0.000000, -0.000000, 1.000000>,
        <0.000001, 0.000000, -1.000000>,
        <-0.000000, -1.000000, -0.000000>,
        <1.000000, 0.000000, 0.000000>,
        <-1.000000, 0.000000, -0.000000>,
        <0.000000, 1.000000, 0.000000>,
        <0.000000, -0.000000, 1.000000>,
        <-1.000000, 0.000000, -0.000000>,
        <0.000000, 0.000000, -1.000000>,
        <1.000000, -0.000000, 0.000000>,
        <-0.000000, -1.000000, -0.000000>,
        <-1.000000, 0.000000, -0.000000>,
        <-1.000000, 0.000000, 0.000000>,
        <0.000000, 1.000000, 0.000000>,
        <-1.000000, 0.000000, 0.000000>,
        <0.000000, 1.000000, 0.000000>,
        <1.000000, -0.000000, -0.000000>,
        <1.000000, -0.000000, 0.000000>
    }
    texture_list{1, texture { pigment_pattern { T_Map_Cube }
            texture_map {
                [0.0 T_Mix_1_Cube]
                [1.0 T_Mix_2_Cube]
    }}}
    face_indices {
        44,
        <0,1,2>, 0,0,0,
        <0,2,3>, 0,0,0,
        <4,7,6>, 0,0,0,
        <4,6,5>, 0,0,0,
        <0,4,10>, 0,0,0,
        <0,10,8>, 0,0,0,
        <1,5,6>, 0,0,0,
        <1,6,2>, 0,0,0,
        <2,6,7>, 0,0,0,
        <2,7,3>, 0,0,0,
        <4,0,3>, 0,0,0,
        <4,3,7>, 0,0,0,
        <1,0,8>, 0,0,0,
        <1,8,9>, 0,0,0,
        <5,1,9>, 0,0,0,
        <5,9,11>, 0,0,0,
        <4,5,11>, 0,0,0,
        <4,11,10>, 0,0,0,
        <12,13,14>, 0,0,0,
        <12,14,15>, 0,0,0,
        <16,17,18>, 0,0,0,
        <16,18,19>, 0,0,0,
        <12,20,21>, 0,0,0,
        <12,21,16>, 0,0,0,
        <15,14,18>, 0,0,0,
        <15,18,17>, 0,0,0,
        <14,13,19>, 0,0,0,
        <14,19,18>, 0,0,0,
        <16,19,13>, 0,0,0,
        <16,13,12>, 0,0,0,
        <15,22,20>, 0,0,0,
        <15,20,12>, 0,0,0,
        <17,23,22>, 0,0,0,
        <17,22,15>, 0,0,0,
        <16,21,23>, 0,0,0,
        <16,23,17>, 0,0,0,
        <8,10,21>, 0,0,0,
        <8,21,20>, 0,0,0,
        <11,9,22>, 0,0,0,
        <11,22,23>, 0,0,0,
        <10,11,23>, 0,0,0,
        <10,23,21>, 0,0,0,
        <9,8,20>, 0,0,0,
        <9,20,22>, 0,0,0
    }
    normal_indices {
        44,
        <10,10,10>,
        <10,10,10>,
        <8,8,8>,
        <8,8,8>,
        <1,1,1>,
        <1,1,1>,
        <12,12,12>,
        <12,12,12>,
        <13,13,13>,
        <13,13,13>,
        <15,15,15>,
        <15,15,15>,
        <5,5,5>,
        <5,5,5>,
        <11,11,11>,
        <11,11,11>,
        <18,18,18>,
        <18,18,18>,
        <8,8,8>,
        <8,8,8>,
        <10,10,10>,
        <10,10,10>,
        <14,14,14>,
        <14,14,14>,
        <17,17,17>,
        <17,17,17>,
        <19,19,19>,
        <19,19,19>,
        <4,4,4>,
        <4,4,4>,
        <9,9,9>,
        <9,9,9>,
        <6,6,6>,
        <6,6,6>,
        <16,16,16>,
        <16,16,16>,
        <0,0,0>,
        <0,0,0>,
        <7,7,7>,
        <7,7,7>,
        <3,3,3>,
        <3,3,3>,
        <2,2,2>,
        <2,2,2>
    }
    interior {
        ior 1.000000
    }


}
//----Blender Object Name:Cube----
object {
    Cube
    matrix <3.000000, 0.000000, 0.000000,  0.000000, -0.000000, -3.000000,
0.000000, 1.868832, -0.000000,  0.000000, 0.000000, 0.000000>

}
//----Blender Object Name:Cube_001----
object {
    Cube_001
    matrix <3.000000, 0.000000, 0.000000,  0.000000, -0.000000, -1.949719,
0.000000, 1.868832, -0.000000,  0.000000, 0.000000, 0.098744>

}
//----Blender Object Name:Plane_001----
object {
    Plane_001
    matrix <5.338935, 0.000000, 0.000000,  0.000000, -0.000000, -5.338935,
0.000000, 5.338935, -0.000000,  -2.303558, 1.657419, 1.990753>

}
//----Blender Object Name:Plane----
object {
    Plane
    matrix <3.974819, 0.000000, 0.000000,  0.000000, -0.000000, -5.989536,
0.000000, 3.974819, -0.000000,  0.000000, -1.738466, 1.724134>

}

light_source {
    < 0,0,0 >
    color rgb<2, 2, 2>
    media_interaction off
    matrix <1.000000, 0.000000, 0.000000,  0.000000, -0.000000, -1.270558,
0.000000, 1.000000, -0.000000,  0.001291, 1.166238, -0.000001>
}

light_source {
    < 0,0,0 >
    color rgb<2.72, 2.72, 2.72>
    fade_distance 14.999991
    fade_power 2
    matrix <-0.290865, -0.055189, -0.955171,  -0.771101, 0.604525, 0.199883,
0.566393, 0.794672, -0.218391,  11.125839, 6.465459, -0.060348>
}

camera {
    perspective
    location  <0, 0, 0>
    look_at  <0, 0, -1>
    right <-1.7777777777777777, 0, 0>
    up <0, 1, 0>
    angle  65.920597
    rotate  <-1.953649, 0.934839, -0.000000>
    translate <0.023297, -0.464718, 5.683205>
}

////////////////////////////////////////////////////////////////////////////

Render time very long!!!! 10 hours
In what reason of such difference? 11 minutes against 10 hours

Post a reply to this message

"LanuHum" <Lan### [at] yandexru> wrote:
> In documentation there is an example
>
///////////////////////////////////////////////////////////////////////////////
>
> Render time: 11 m
> I created a similar scene in Blender, using mesh2
>
> ///////////////////////////////////////////////////////////////////////////////
>
> //----------------------------------------------
> //--Export to Povray from Blender--
> //----------------------------------------------
>
> ////////////////////////////////////////////////////////////////////////////
>
> Render time very long!!!! 10 hours
> In what reason of such difference? 11 minutes against 10 hours

Maybe you look at this simple example:

background { rgb <0.3, 0.6, 0.9> } versus background {rgbt<0.0509, 0.0509,
0.0509, 0>}

I think that calculatin inside POV-Ray using a Integer is faster then a Float.
But i could be wrong

Post a reply to this message

"gharryh" <h.a### [at] harry-arendsnl> wrote:

> Maybe you look at this simple example:
>
> background { rgb <0.3, 0.6, 0.9> } versus background {rgbt<0.0509, 0.0509,
> 0.0509, 0>}
>
> I think that calculatin inside POV-Ray using a Integer is faster then a Float.
> But i could be wrong


No! Povray bad work with mesh
All vertices coords - float. They can't be presented int

Post a reply to this message

> "LanuHum" <Lan### [at] yandexru> wrote:
>> In documentation there is an example
>>
> ///////////////////////////////////////////////////////////////////////////////
>>
>> Render time: 11 m
>> I created a similar scene in Blender, using mesh2
mesh or mesh2 are realy the same, internaly, once parsed.
>>
>> ///////////////////////////////////////////////////////////////////////////////
>>
>> //----------------------------------------------
>> //--Export to Povray from Blender--
>> //----------------------------------------------
>>
>> ////////////////////////////////////////////////////////////////////////////
>>
>> Render time very long!!!! 10 hours
>> In what reason of such difference? 11 minutes against 10 hours
>
> Maybe you look at this simple example:
>
> background { rgb <0.3, 0.6, 0.9> } versus background {rgbt<0.0509, 0.0509,
> 0.0509, 0>}
Both use floats. It don't mather how many decimal digits there are, 
internaly, it's always a double precision float.

>
> I think that calculatin inside POV-Ray using a Integer is faster then a Float.
> But i could be wrong
>
>
>

POV-Ray always use floats, never integers. Rendering rgb 1 and 
rgb<1,13/47,0.013752168> take exactly the same time.

In the purely POV-Ray scene, you use simple pigments and textures.

The blender textures use pigment_pattern with a texture_map. Those take 
longer to render.

Your light_source is a basic point_light, blender's light_source is a 
fading one. The fading light_source is a little slower as the distance 
must be calculated and the fading applied.

For your media, you use samples 30, and you use a very small extinction 
value of 0.1.
For the blender's media, it's samples 256, and use a HUGE, I may say 
insane, extinction value of 4.871 !

If your mesh contains long and narrow triangles, those can't be bounded 
effeciently. Subdividing the mesh, or not decimating it, can make it 
render faster.





Alain

Post a reply to this message

On 17-6-2013 16:30, LanuHum wrote:
> No! Povray bad work with mesh

On the contrary, POV-Ray works perfectly with meshes. It is the quality 
of the meshes that may be a problem, for instance when triangle vertices 
are not welded.

I recommend that - before rendering in POV-Ray - you pass your Blender 
mesh through Poseray ( https://sites.google.com/site/poseray/ ). There, 
you can weld the loose vertices, subdivide the mesh, etc. Then, you can 
export in mesh2 format and render in POV-Ray.

Thomas

Post a reply to this message

Thomas de Groot <tho### [at] degrootorg> wrote:
> On 17-6-2013 16:30, LanuHum wrote:
> > No! Povray bad work with mesh
>
> On the contrary, POV-Ray works perfectly with meshes. It is the quality
> of the meshes that may be a problem, for instance when triangle vertices
> are not welded.
>
> I recommend that - before rendering in POV-Ray - you pass your Blender
> mesh through Poseray ( https://sites.google.com/site/poseray/ ). There,
> you can weld the loose vertices, subdivide the mesh, etc. Then, you can
> export in mesh2 format and render in POV-Ray.
>
> Thomas

It is a bad way! If animation?

Povray reads simple text the file.
This file can be created in Poseray, and I can write just the same file hands.
It is necessary to know a mistake.

Mesh created in Blender, without problems is read by other renderer: Luxrender,
Yafaray. There are no problems as with export to OBJ.

You could find the wrong ranges in the example given by me?
Where there triangle vertices are not welded.

Post a reply to this message

> It is a bad way! If animation?

Yes in case of an animation this isn't a good idea. In case of a still it is the
way to go. As Alain mentioned your problem is with the media settings. The first
example uses an extinction value of 0.01 the second 4.871. The first scene has
30 samples within cube_001 the second 256 and there are some different settings
with the light_sources. These settings causes the prolonged rendering time.
Thomas mentioned problems with bad defined meshes which is true in general, but
not with your simple ones here. You have only a cube and such but not Lucy. I
think he only tried to give you an other hint, what could be got wrong from his
long time experience with POV.

But your problem comes from your settings for the scattering media. May be you
have misunderstood some parametrisations within Blender or there is a bug within
the exporter from Blender to POV. I propose to ask the Blender Community as
well.

Best regards,
Michael

BTW: Your first scene took 7 min 40 sec at my (new) system, the second is at 2%
after 20 min. So I can reproduce your problem. I used the scattering values from
the first scene for the second and yielded rendering times close to the first,
but unfortunatelly another lighting. Excuse me, that I cannot go further into
this issue, since I have my own renderings pending.

Post a reply to this message

On 18-6-2013 20:43, MichaelJF wrote:
>
>> It is a bad way! If animation?
>
> Yes in case of an animation this isn't a good idea. In case of a still it is the
> way to go.

I do not see the problem in the case of an animation, as Poseray is only 
used once, before any animation is started...

But that leads us away from the thread's topic doesn't it?  ;-)

As Alain mentioned your problem is with the media settings. The first
> example uses an extinction value of 0.01 the second 4.871. The first scene has
> 30 samples within cube_001 the second 256 and there are some different settings
> with the light_sources. These settings causes the prolonged rendering time.

Media samples can certainly be brought down. Additionally, there seems 
to be a /coincident surface/ problem with the wall at left, judging from 
the artefacts there.

> Thomas mentioned problems with bad defined meshes which is true in general, but
> not with your simple ones here. You have only a cube and such but not Lucy. I
> think he only tried to give you an other hint, what could be got wrong from his
> long time experience with POV.

Just to say that POV-Ray and meshes (mesh2 in particular) work very well 
together :-)

The meshes from Blender look OK but I am no expert on Blender and its 
exporter to POV-Ray.

Thomas

Post a reply to this message

I don't know how you managed to get this media sample count from the official
blender exporter since the media samples allowed by its interface are a maximum
number of 100.

About the pigment_pattern with image map slowdown, how much does it really slow
things down? Because that's really needed to get to more complex texture
influence export  corner cases like specular mapping with a texture. To
implement scripted conditions that detect more cleverly the complexity of the
scene in original file and export only with necessary features, I need to know
how much speed could be gained, and if it's really worth it.

Anyway, LanuHum, this is a very interesting type of comparison to improve the
exporter. there could be such tests for many other features with very simple
scenes also usefull to spot regressions of exporter versions. I think I did put
a few scenes on the exporter wiki for that already and I might have a few others
on my local drive at home. ask me by mail if you want them and please could you
also send me any updates to your version of the script when you manage to get it
closer to the official one so that I can try to merge the two versions.

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"Mr" <nomail@nomail> wrote:
> I don't know how you managed to get this media sample count from the official
> blender exporter since the media samples allowed by its interface are a maximum
> number of 100.
>
> About the pigment_pattern with image map slowdown, how much does it really slow
> things down? Because that's really needed to get to more complex texture
> influence export  corner cases like specular mapping with a texture. To
> implement scripted conditions that detect more cleverly the complexity of the
> scene in original file and export only with necessary features, I need to know
> how much speed could be gained, and if it's really worth it.
>
> Anyway, LanuHum, this is a very interesting type of comparison to improve the
> exporter. there could be such tests for many other features with very simple
> scenes also usefull to spot regressions of exporter versions. I think I did put
> a few scenes on the exporter wiki for that already and I might have a few others
> on my local drive at home. ask me by mail if you want them and please could you
> also send me any updates to your version of the script when you manage to get it
> closer to the official one so that I can try to merge the two versions.

I work over the exporter.
I don't hope that the official version will reach functionality.
I change limits, studying Povray documentation.
I have not enough time
In detail on Saturday or on Sunday, on days off

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