POV-Ray rendering clipping faces

[paoligno90]

Hello!

I recently started using FreeCAD to design some vacuum chambers. I create a part combining many .STEP files. I want to render the final object using POV-Ray and I get a strange behavior that I can't manage to explain. Attached are the model and the screenshots in the .zip archive. I render the entire assembly and some surfaces are completely invisible. You can see the differences in the files "Full*.png". If I make a big boolean cut with a cube, the faces appear correctly (files Big_Cut*.png), but if I cut a bit less entire pieces of the part disappear (files Small_Cut*.png). May this be related to the maximum number of polygons that FreeCAD is able to add to the POV-Ray project? Is there a way to overcome this?
Thank you very much

[papyblaise]

Hello
Maybe , you have to do a total fuse of all parts , if you cut the main pipe, you obtain the alf pipe only wiyhout the flanges

[schupin]

Did you select all the part you want to render when you add it to the povray project ?

EDIT : if you've made it from the provided .step file, you shouldn't have problem. I'll try it by my side

[paoligno90]

Hello
Maybe , you have to do a total fuse of all parts , if you cut the main pipe, you obtain the alf pipe only wiyhout the flanges

The part is already a single big piece.

Did you select all the part you want to render when you add it to the povray project ?

EDIT : if you've made it from the provided .step file, you shouldn't have problem. I'll try it by my side

It's only one single part. I tried with various cuts to see the differences in the .pov file. It seems that the number of meshes increases reducing the cut size and then it goes down losing some and therefore losing details and faces. I guess I will have to redo the part keeping different pieces and render them not as single piece, but still this is a very weird behavior

[schupin]

I took your .step and did this render with povray :

TstRayVaccum.png (348.27 KiB) Viewed 1342 times

I had zero issue
I'm using

Code: Select all

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.17091 (Git)
Build type: Release
Branch: master
Hash: 4a0be9d3ba28ca14906574370de1f2f005af0d54
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)

And 3.7 version of povray

(I modified the .pov file according to this pages : http://www.f-lohmueller.de/pov_tut/backgrnd/p_sky10.htm and https://www.freecadweb.org/wiki/Tutoria ... AD_POV_ray)

[quick61]

I took your .step and did this render with povray :
TstRayVaccum.png


I had zero issue
I'm using

Code: Select all

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.17091 (Git)
Build type: Release
Branch: master
Hash: 4a0be9d3ba28ca14906574370de1f2f005af0d54
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)

And 3.7 version of povray

(I modified the .pov file according to this pages : http://www.f-lohmueller.de/pov_tut/backgrnd/p_sky10.htm and https://www.freecadweb.org/wiki/Tutoria ... AD_POV_ray)

That's a very nice render! Would you mind sharing the script for that? you can copy and paste with the </> code tag or rename the .pov to .txt and attach. Looks like the HDRI environment mapping might make for a nice template.

Mark

[schupin]

That's a very nice render! Would you mind sharing the script for that? you can copy and paste with the </> code tag or rename the .pov to .txt and attach. Looks like the HDRI environment mapping might make for a nice template.

Sure, here is the .pov file (I didn't put the mesh part that is a bit long (the .pov file is 35 Mo)) :

Code: Select all

// Persistence of Vision Ray Tracer Scene Description File
// for FreeCAD (http://www.freecadweb.org)

#version 3.7;

#include "colors.inc"
#include "metals.inc"  
#include "rad_def.inc"


// ----------------------------------------
#declare Rad_Quality = 3;

global_settings {
    assumed_gamma 1.0
    ambient_light color rgb <1.0,1.0,1.0>
    max_trace_level 20

#switch (Rad_Quality)
 #case (1)
    radiosity { // Settings 1 (fast)
        Rad_Settings(Radiosity_Fast, off, off)
    }
    #break
 #case (2)
    radiosity { // Settings 2 (medium quality)
        Rad_Settings(Radiosity_2Bounce, on, on)
    }
    #break
 #case (3)
    radiosity{ // Settings 3 (high quality)
        Rad_Settings(Radiosity_IndoorHQ, on, on)
        recursion_limit 2
    }
    #break
#end
}  

// ----------------------------------------


sky_sphere{ pigment{ image_map{ hdr "building_probe.hdr"
                                gamma 1.1
                                map_type 1 interpolate 2 }
                   }
            rotate < 0,10,0>  // adapt it to your direction
          } // end sky_sphere
                  

// ----------------------------------------

plane {
  y, -1
  texture { pigment {rgb <0.05,0.05,0.06>} finish {ambient 0.0 reflection 0.05 specular 0.0} }
}           


#declare T_metal = texture {T_Silver_1B}

// declares position and view direction

// Generated by FreeCAD (http://www.freecadweb.org/)
#declare cam_location =  <431.012,559.256,-486.816>;
#declare cam_look_at  = <-34.5,222.5,-8.83868>;
#declare cam_sky      = <-0.254258,0.889696,0.379203>;
#declare cam_angle    = 51; 
camera {
  location  cam_location
  look_at   cam_look_at
  sky       cam_sky
  angle     cam_angle 
  right x*800/600
}  

//default light
light_source {
  cam_location + cam_angle * 100
  color rgb <1.5, 1.5, 1.5>
} 

// Written by FreeCAD http://www.freecadweb.org/
// face number1 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
#declare Pov_Part__Feature1 = mesh2{

MESH

}
// instance to render
object {Pov_Part__Feature
 texture {T_metal  }
}

The hdri image was taken here : http://www.pauldebevec.com/Probes/building_probe.hdr

[quick61]

That's a very nice render! Would you mind sharing the script for that? you can copy and paste with the </> code tag or rename the .pov to .txt and attach. Looks like the HDRI environment mapping might make for a nice template.

Sure, here is the .pov file (I didn't put the mesh part that is a bit long (the .pov file is 35 Mo)) :
[snip code}

Thanks!

[schupin]

It's only one single part. I tried with various cuts to see the differences in the .pov file. It seems that the number of meshes increases reducing the cut size and then it goes down losing some and therefore losing details and faces. I guess I will have to redo the part keeping different pieces and render them not as single piece, but still this is a very weird behavior

I'm trying to make cuts in your part to do a slice render and I'm having some issues : I can't manage to do a boolean substraction with a cube to have a cut... Did you succeed doing such a cut in FreeCAD before render it ?

[paoligno90]

That's a very nice render! Would you mind sharing the script for that? you can copy and paste with the </> code tag or rename the .pov to .txt and attach. Looks like the HDRI environment mapping might make for a nice template.

Sure, here is the .pov file (I didn't put the mesh part that is a bit long (the .pov file is 35 Mo)) :

Code: Select all

// Persistence of Vision Ray Tracer Scene Description File
// for FreeCAD (http://www.freecadweb.org)

#version 3.7;

#include "colors.inc"
#include "metals.inc"  
#include "rad_def.inc"


// ----------------------------------------
#declare Rad_Quality = 3;

global_settings {
    assumed_gamma 1.0
    ambient_light color rgb <1.0,1.0,1.0>
    max_trace_level 20

#switch (Rad_Quality)
 #case (1)
    radiosity { // Settings 1 (fast)
        Rad_Settings(Radiosity_Fast, off, off)
    }
    #break
 #case (2)
    radiosity { // Settings 2 (medium quality)
        Rad_Settings(Radiosity_2Bounce, on, on)
    }
    #break
 #case (3)
    radiosity{ // Settings 3 (high quality)
        Rad_Settings(Radiosity_IndoorHQ, on, on)
        recursion_limit 2
    }
    #break
#end
}  

// ----------------------------------------


sky_sphere{ pigment{ image_map{ hdr "building_probe.hdr"
                                gamma 1.1
                                map_type 1 interpolate 2 }
                   }
            rotate < 0,10,0>  // adapt it to your direction
          } // end sky_sphere
                  

// ----------------------------------------

plane {
  y, -1
  texture { pigment {rgb <0.05,0.05,0.06>} finish {ambient 0.0 reflection 0.05 specular 0.0} }
}           


#declare T_metal = texture {T_Silver_1B}

// declares position and view direction

// Generated by FreeCAD (http://www.freecadweb.org/)
#declare cam_location =  <431.012,559.256,-486.816>;
#declare cam_look_at  = <-34.5,222.5,-8.83868>;
#declare cam_sky      = <-0.254258,0.889696,0.379203>;
#declare cam_angle    = 51; 
camera {
  location  cam_location
  look_at   cam_look_at
  sky       cam_sky
  angle     cam_angle 
  right x*800/600
}  

//default light
light_source {
  cam_location + cam_angle * 100
  color rgb <1.5, 1.5, 1.5>
} 

// Written by FreeCAD http://www.freecadweb.org/
// face number1 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
#declare Pov_Part__Feature1 = mesh2{

MESH

}
// instance to render
object {Pov_Part__Feature
 texture {T_metal  }
}

The hdri image was taken here : http://www.pauldebevec.com/Probes/building_probe.hdr

How did you manage to do that? When I export the .pov file it is only 600KB!! I don't have enough meshes!