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dunawapj4-Participant
4-Participant
June 23, 2022
Solved

DMT appearance/color space definition

  • June 23, 2022
  • 1 reply
  • 2325 views

I am using Creo Parametric - Release 8.0 (connected) Release 8.0 and Datecode8.0.4.0


Hello, I need to make some custom color palettes for our organization. I haven't been able to find a detailed rundown of the structure of dmt files, and would like some help determining the meaning of each variable.

I have seen opened some files and have seen:
ambient_color - with 4 values scaled from 0 to 1
diffuse_color - same values as ambient
specular_color - same values as ambient
(Perhaps three of these values are scaled RGB, but I am not sure how to utilize these three sets of color definition.)

diffuse - value 0-1
ambient - value 0-1
shine -value 0-1
intensity - value 0-1
reflection - value 0-1
transparents - value 0-1
index_of_refraction - value 0-?

I believe some of the second group are tied to parameters than can be edited in the appearance manager, but the scaling is different and I don't think it has all of the listed variables as options.

Any information or guides you can offer on creation of a custom dmt file would be appreciated - I know the RGB values of the colors I need and would just like to figure out how these files work.

    Best answer by KenFarley

    In the past I've tried to manually edit the appearance.dmt file to put some custom appearances in, with some limited success, but I've found that I'm generally better off defining new appearances with the appearance manager in Creo itself.

     

    Some of the entries in the files are somewhat odd. For example, they are using RGBA values, but it is not apparent to me that the "A" or "alpha" channel is used - there's a "transparency"  value that determines how opaque an object using the appearance will be.

     

    The colors are all scaled values, from zero to 1 as you mentioned. This is kind of annoying if you're trying to hand edit because most of the tools I have seen tend to specify color components as values from zero to 255 (including Creo's own appearance manager).

     

    When I look at my appearance.dmt file, it seems the ambient and diffuse colors are always the same. I think I tried messing about with them and found it didn't really make a difference? The specular values are what you see when you're getting a bit of a "shine" on the part, like the "highlight" spot on a shaded sphere.

     

    The thing I learned is to be careful naming my colors. I adopted a convention like "clear-grey-light", "clear-grey-dark" and such so the colors are sorted with clear appearances grouped together, etc.

    1 reply

    K
    KenFarley21-Topaz IIAnswer
    21-Topaz II
    June 23, 2022

    In the past I've tried to manually edit the appearance.dmt file to put some custom appearances in, with some limited success, but I've found that I'm generally better off defining new appearances with the appearance manager in Creo itself.

     

    Some of the entries in the files are somewhat odd. For example, they are using RGBA values, but it is not apparent to me that the "A" or "alpha" channel is used - there's a "transparency"  value that determines how opaque an object using the appearance will be.

     

    The colors are all scaled values, from zero to 1 as you mentioned. This is kind of annoying if you're trying to hand edit because most of the tools I have seen tend to specify color components as values from zero to 255 (including Creo's own appearance manager).

     

    When I look at my appearance.dmt file, it seems the ambient and diffuse colors are always the same. I think I tried messing about with them and found it didn't really make a difference? The specular values are what you see when you're getting a bit of a "shine" on the part, like the "highlight" spot on a shaded sphere.

     

    The thing I learned is to be careful naming my colors. I adopted a convention like "clear-grey-light", "clear-grey-dark" and such so the colors are sorted with clear appearances grouped together, etc.

      D
      dunawapj4-ParticipantAuthor
      4-Participant
      June 23, 2022

      Thanks for the help! I've played around in the appearance manager and I think you're right, that that is the way to do it. In the process I've figured out how to edit the dmt file in parallel to speed things up. It seems that the values do align with the parameters I listed, but have different names (example: intensity = highlight). I am a bit surprised there isn't more information readily available on this but reverse engineering it has worked OK.

       

      For now I'm just making my diffuse and specular colors the same as the ambient as you said - not sure on their intended purpose.

       

       

      J
      jpowers_gleason5-Regular Member
      5-Regular Member
      May 12, 2025

      This is a guess for Creo, but typically in CAD programs, the changes to some appearance settings (in this case perhaps those 'ambient' and 'diffuse' values) only show up when doing renderings, not when looking at a "regular" 3D model. 

      Also, I see what you're talking about with the names not lining up... at least compared to what you're referring to and Creo 10 because there is a setting in the Model Appearance Editor called 'Ambient' and I can see that change in the "regular" 3D model immediately.  So, there may still be some missing documentation on these details.

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