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Thread: Lightwave OBJ support

  1. #1
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    Lightwave OBJ support

    I am looking at an OBJ file exported form Lightwave.

    I see it has "Ka" which is the ambient term, which is set at 1 1 1
    Anybody know if LW uses this term for anything?

    Also, I see the file has both "d" and "tr" which both define transparency. "d 1" is for dissolve and "Tr 0" is for transparency.

    Anybody know which term LW uses?

    Can anyone tell me what the "Ke" term is for? It's not part of the original file format. Is it Emmisive? like luminosity?

  2. #2
    Big Kahuna
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    Quote Originally Posted by Dan Ritchie View Post
    I am looking at an OBJ file exported form Lightwave.

    I see it has "Ka" which is the ambient term, which is set at 1 1 1
    Anybody know if LW uses this term for anything?

    Also, I see the file has both "d" and "tr" which both define transparency. "d 1" is for dissolve and "Tr 0" is for transparency.

    Anybody know which term LW uses?

    Can anyone tell me what the "Ke" term is for? It's not part of the original file format. Is it Emmisive? like luminosity?
    where are u seeing this? i did a test and exported a UV mapped object from LW as .obj and opened it again in LW and no probs. also opened the same file in maya and do not see anything unusual (except for the usual image re-linking needed and shading adjustments). what program are u using to open the lw-exported .obj? is it a UV textured .obj export, or procedural textured? nodes? millions of variables here, including how the LW object was shaded originally. specifics, pls.

  3. #3
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    Sorry, I neglected to be more specific. I was looking at the associated material file, not the actual OBJ.

    newmtl Default
    Kd 0.784314 0.784314 0.784314
    Ke 0 0 0
    Ka 1 1 1
    Ks 0 0 0
    Ns 400
    Tr 0
    d 1
    Ni 1
    Tf 1 1 1

    newmtl Teapot
    Kd 0.784314 0.784314 0.784314
    Ke 0 0 0
    Ka 1 1 1
    Ks 0.5 0.5 0.5
    Ns 400
    Tr 0
    d 1
    Ni 1
    Tf 1 1 1

  4. #4
    Registered User jaf's Avatar
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    I think Dan is referring to editing/viewing the .mtl obj file. looks like this:

    ...
    newmtl s2
    Ka 0 0 0
    Kd 0 0 1
    Ks 0 0 0
    Ni 1
    Ns 400
    Tf 1 1 1
    d 1
    ...

    [edit] Sorry Dan, looks like you posted while I was too
    Last edited by jaf; 07-21-2017 at 01:04 PM.
    22Apr2020: Lightwave 2019.1.5 Build 3134, win10 pro 1909, AMD Ryzen 1800+, 64 GB mem, EVGA GeForce GTX 1080 ti v445.87 (20Apr20)

  5. #5
    Big Kahuna
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    i see it now when i open the mtl file in notepad. check out the obj wiki under basic materials section:

    https://en.wikipedia.org/wiki/Wavefront_.obj_file

  6. #6
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    after some experimentation, I see that Ka is linked to diffuse, and Ke is linked to luminosity. There is no setting for reflectivity.

  7. #7
    Big Kahuna
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    Quote Originally Posted by Dan Ritchie View Post
    after some experimentation, I see that Ka is linked to diffuse, and Ke is linked to luminosity. There is no setting for reflectivity.
    i was thinking reflectance, which is C4D's term for specularity, which also includes reflection. i work in both side-by-side, so i merge the terminology. lol. ks would be the mtl/obj code for spec.

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