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Dan Ritchie
07-21-2017, 11:11 AM
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?

TreyX
07-21-2017, 11:37 AM
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.

Dan Ritchie
07-21-2017, 12:55 PM
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

jaf
07-21-2017, 12:58 PM
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

TreyX
07-21-2017, 05:11 PM
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

Dan Ritchie
07-22-2017, 12:03 PM
after some experimentation, I see that Ka is linked to diffuse, and Ke is linked to luminosity. There is no setting for reflectivity.

TreyX
07-22-2017, 03:22 PM
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.