#1 - Using POV-Ray to Render Pro/ENGINEER Models 

I first became aware of POV-Ray while reading a Pro/E Magazine article in late 1995. I immediately tried to use POV-Ray to render Pro/E models myself. There was only one problem, how was I going to convert the Pro/E data to POV-Ray format like the article talked about? I did not have the time to write such a program. It didn't take long until I hooked up with Bruce Bodnyk on the Pro/E newsgroup and he told me that he had written a converter called SLP2POV. So I downloaded a copy and off I went. Until recently, the converted data, in POV-Ray .inc format, had to be edited if you wanted the colors in Pro/E to "map" automatically to textures in POV-Ray. With the addition of the SLP2POV "-T option", it is now possible to render a complete Pro/E part or assembly without having to edit the POV-Ray include (.inc) file 

Below is a description of how to use POV-Ray to render Pro/ENGINEER Models, with emphasis on using the -T option. 

1. The first step to converting Pro/E data to POV-Ray is to create a render file in Pro/E. Here is my mapkey for starting the render file export command: 

mapkey slp #interface;#export;#Render 

If you are in part mode when you do this, all you need to do is set the chord height. If you are in assembly mode you have two options, one is to render the whole assembly, the other is to render only selected parts in the assembly. To select everything in the assembly, select #Exclude;#Done-Select, this will select everything. To select parts individually, use #Include. Next, set the desired chord height. Pick #Output, select the desired coordinate system and type in the desired output filename. The render file that you created will be in your working directory and has a .slp extension. Thats it! 

Render files represent the surfaces of the solid model with LOTS of small polygons. These polygons also have normal vectors and colors associated with them. The format required by POV-Ray contains the same information, but formatted differently. The program SLP2POV is what you will need to do the conversion.  

Here is the description provided in the SLP2POV documentation: 

DESCRIPTION 

slp2pov translates a Pro/ENGINEER .slp file in "Render" format to a .inc
file for use with POV-Ray where the .inc file has the same base name as the .slp file.
The program creates a single POV-Ray object whose name is the base name of the input
file converted to upper case. The file generated contains "declare"
definitions for all colors in the render file making it easy to adjust the color of an 
object.......

At this point I am going to discuss using the -T option/method, the SLP2POV documentation describes the other options/methods. The -T option allows the "automatic mapping" of a particular color in Pro/E to a particular texture in POV-Ray.  

2. The key to this technique is to always use the same color in Pro/E for any particular material (texture). Thus, all titanium parts in Pro/E are ALWAYS the same color, etc, etc. These actual colors are irrelevant, just be consistent! It does help if they are close to the actual color so that they look good if you shade the part/assembly in Pro/E. HINT: Some parts will be a dark color, so turn off the color display found in #Environment if the parts are hard to see. It will become apparent why shortly. This task is easier if you create Pro/E color map files (color.map) to store your predefined colors. Otherwise you have the task of "mixing" the color each time.  

Pro/E color.map files are of the following format: 

0.810 0.620 0.000 0.900 0.900 0.800 0.500 1.000 1.000 1.000
0.000 0.900 1.000 100.000 0 90
NO_TEXTURE NO_TEXTURE NO_TEXTURE
0.900 0.900 1.000 0.670 0.900 0.800 0.610 1.000 1.000 1.000
0.000 0.900 1.000 100.000 0 90
NO_TEXTURE NO_TEXTURE NO_TEXTURE
0.170 0.170 0.170 0.670 0.900 0.800 0.610 1.000 1.000 1.000
0.000 0.900 1.000 100.000 0 90
NO_TEXTURE NO_TEXTURE NO_TEXTURE
0.700 0.700 0.670 0.900 0.900 0.800 0.500 1.000 1.000 1.000
0.000 0.900 1.000 100.000 0 90
NO_TEXTURE NO_TEXTURE NO_TEXTURE
1.000 1.000 1.000 0.900 0.900 0.800 0.500 1.000 1.000 1.000
0.000 0.900 1.000 100.000 0 90
NO_TEXTURE NO_TEXTURE NO_TEXTURE
0.850 0.850 0.860 0.670 0.900 0.800 0.610 1.000 1.000 1.000
0.000 0.900 1.000 100.000 0 90
NO_TEXTURE NO_TEXTURE NO_TEXTURE
0.800 0.800 0.900 0.670 0.900 0.800 0.610 1.000 1.000 1.000
0.000 0.900 1.000 100.000 0 90
NO_TEXTURE NO_TEXTURE NO_TEXTURE

As far as I know, this file can contain up to seven colors when using X-Windows and up to twenty colors when using hardware graphics options. The seven colors in this file are shown in bold, the first color is: red 0.810 green 0.620 blue 0.000. In the context of this discussion the rest of this info is irrelevant, just leave it as-is. This file can be generated initially by using the save option under #View;#Cosmetic;#Appearances and then modifed for the other versions. I use four color.map files, I swap them out as needed by using the following cshell script. 

#!/bin/csh
cp /home/$USER/PROE/COLOR_MAPS/"color"$1".map" /v/pro-data/baldwin/WORK/color.map

Basically all it does is copy one of the files called color1.map...color4.map to my work directory with a new name of color.map. It could easily be a batch file on a NT machine. Note, these files are in a different location to avoid being erased! The only drawback to this method is that Pro/E will not recognize a change in the color.map file if it is already running. So if you are already in Pro and you need a color contained in one of the other color.map files, you will have to restart Pro. Its still better than "mixing" the colors everytime! 

3. Following the above technique produces a render file that contains objects of unique colors and those colors map to a unique texture in POV-Ray. In order for SLP2POV to know how to map those colors you need what I call a pseudo color include file. Here is my file and a sample, I call it protext.inc: 

...... 

#declare black_al = color red .17 green .17 blue .17

#declare p_stainless = color red 1 green 1 blue 1

#declare acrylic = color red .8 green .8 blue .9

#declare titanium = color red .71 green .7 blue .72

#declare black_delrin = color red .2 green .2 blue .2

#declare white_delrin = color red .80 green .80 blue .80

.....

This file tells SLP2POV that all colors of color red .17 green .17 blue .17 should be converted to the texture called black_al which happens to be my name for my black anodized aluminum texture.  

I have a sample .slp file called tut1.slp that I have created of the following Pro/E assembly (please excuse the poor image quality). 

Below are the proper SLP2POV command line options and output for this render file: 

> slp2pov -c protext.inc -t .05 -d -T tut1.slp
Reading .slp file
...................................
Writing .inc file
...................................

Pro/ENGINEER to Persistence of Vision Ray Tracer
       Translator Ver 1.6

Extents of : TUT1 
     Min : < -2.852930, -3.360899, -0.000000 >
     Max : < 14.012910, 11.369110, 5.680000 >
     Triangle Count : 35088

Colors :
     COLOR_0 < 1.000, 1.000, 1.000 > ==> p_stainless 
     COLOR_1 < 0.170, 0.170, 0.170 > ==> black_al 
     COLOR_2 < 0.099, 0.099, 0.099 > ==> black_dull 
     COLOR_3 < 0.896, 0.896, 1.000 > ==> clear_al 
     COLOR_4 < 0.205, 0.205, 0.205 > ==> black_delrin 
     COLOR_5 < 0.800, 0.800, 0.900 > ==> acrylic 
     COLOR_6 < 0.810, 0.620, 0.000 > ==> gold_al 
     COLOR_7 < 0.800, 0.700, 0.000 > ==> gold_pins 
     COLOR_8 < 0.710, 0.700, 0.720 > ==> titanium 
     COLOR_9 < 0.404, 0.398, 0.105 > ==> mil_conn_green 
     COLOR_10 < 0.850, 0.850, 0.860 > ==> m_stainless 
     COLOR_11 < 0.802, 0.802, 0.802 > ==> white_delrin 
     COLOR_12 < 0.000, 0.000, 0.860 > ==> positronic_blue 
     COLOR_13 < 0.660, 0.660, 0.660 > ==> monel 
     COLOR_14 < 0.200, 0.850, 0.500 > ==> vero_green 
     COLOR_15 < 0.150, 0.150, 0.150 > ==> black_rough_paint 
     COLOR_16 < 1.000, 0.000, 0.000 > ==> red_plastic 
> 

Here are explanations of the options that I use: 

-c color_include_file_path  

This option will cause the rgb color definitions present in the .slp file to be replaced with the closest POV-Ray color defined in the specified include file. (See -t) 

-t tolerance  

Specifies how close an rgb color definition in the .slp file has to be to a color in the color include file for them to be considered the same.  

-T  

This option will cause the color definitions to be treated as textures rather than pigments. This is intended for users who have rgb colors defined in one include file (protext.inc in my case) for use with the translator and corresponding texture definitions in another include file (arltext.inc in my case) which will be used when doing the rendering. 

Note that SLP2POV has found and mapped 17 colors to the appropriate POV-Ray textures! The output file is called tut1.inc and it contains a single POV-Ray "object". This object can be a single part or an assembly of parts. For this example, it is an assembly of parts. This object is used in the POV-Ray scene by "including" this file, tut1.inc, in the POV-Ray scene file.  

4. The last thing that you need is a texture definition file for use with POV-Ray. It needs to be included in each scene file (.pov). My file is called arltext.inc, here is a sample: 

#declare gold_al = texture {pigment {color red .9 green .8 blue .5}
   finish {specular .8 roughness .005 reflection .1 ambient .25 diffuse .5 brilliance 4} }

#declare clear_gold_al = texture {pigment {color red .9 green .8 blue .5 filter 1}
   finish {specular .8 roughness .005 reflection .1 ambient .25 diffuse .5 brilliance 4} }

#declare clear_al = texture {pigment {White}
   finish {specular .6 roughness .005 reflection .1 ambient .25 diffuse .5 brilliance 4} }

#declare black_al = texture {pigment{Black}
   finish {specular .7 roughness .03 reflection .05 ambient .2 diffuse .5 brilliance 4} }

Note that these texture names correspond to the ones found in the pseudo color file, in my case protext.inc!  

Typically, I include this include file in a "standard" scene file and render it. I can create this render file, run it thru SLP2POV and have the first shot at a POV-Ray rendering done in about 5 minutes. Here is the POV-Ray scene file for this example, the include file is too big to be provided, I don't have enough space here at Geocities.. Of course not all assemblies work in a single standard include file, so they will have to be modified as needed. 

Here is the POV-Ray image of this Pro/E assembly: 

All objects and textures but the wood floor were converted from Pro/E to POV-Ray by SLP2POV! Pretty COOL huh! 

Thanks goes out to Bruce Bodnyk for his hard work writing SLP2POV and to his decision to share it with the rest of us!