View Full Version : .mtl file format

04-18-2012, 07:58 PM
I purchased a roulette wheel model from turbosquid which was available as an obj file. It came with surfaces and a .mtl file which I understand is for maintaining the surface assignments. Is this something that can be used in LW?

When opening the surface editor it appears the model is a single object (it's not broken up in layers in the modeler although I can break it up if the .mtl file is intended for other 3D apps. I have zero experience with this.

Can anyone point me to the best way to handle this?


04-18-2012, 08:19 PM
As long as the MTL and OBJ have the same name (minus the extension) LightWave should automatically recognize the MTL and load the surfaces when you open the OBJ. As for layers OBJ is not nearly as versatile as LWO so it can't contain things like layers or morphs.

04-19-2012, 06:16 AM
The file shipped in directories that suggest it was set up this way. As nice as the reference images looked at turbosquid, without layers I don't see how I can separate the wheel from the wheel housing to make it spin or create a hierarchy to parent things that should remain together.

Additionally, I rendered a test in layout and got nothing. Is there something in particular I should be doing to insure that file's info crosses over? It appears in the surface editor that these surfaces are applied but I'm not getting them to render.

Lastly can I change the file extension to .lwo from .obj or is there something involved? I sort of thought they were the same.

Thanks for your help.

04-19-2012, 06:50 AM
Either mtl and obj are text files, so you can just open them in text editor. That's why it's so big size.
lws is also text file.
lwo is binary file.

04-19-2012, 07:01 AM
Do you see the objects(s) in the viewports or are they blank? If you do not see them, try hitting a to autoscale the viewports to fit the object in the viewport wholely. If you still see nothing, do you see a poly count for the object from within Modeler or Layout?

Another thing could be that the polys are flipped. Hit f.....

lots of posiblities here.

One way of seperating out you object would be to select a poly or surface by name then expand selection, and cut and then paste into a new layer. This way, you could seperate out your object nicely into layers/parts and then label them.

If still having problems, let me know.

04-19-2012, 07:52 AM
jburford, I'm familiar with all the suggested techniques you posted with respect to seeing, flipping and separating my model. My confusion is working with .mtl files.

I do see the model, understand how to break it apart, select polys and expand the selection for cutting/layering. What I'm not clear about is how this is going to affect the surfaces applied with the .mtl file.

Sensei, you mention the .mtl file is a text file and it can be opened with a tect editor. That's great, then what. I don't have any experience with these files types or have a clue what to look for or do with it once opened.

My LW experience is pretty much limited to logo animation. I have practically zero experience using UV mapping (although I did do it once - ha ha). If there are any really good tutorials that would help I'm all ears otherwise I'll just break up this model and use the texture editor to apply surfaces the way I've always done.

Thanks for all the help. Just plugging along learning what I can as different projects come along.


04-19-2012, 07:59 AM
Open your obj file in text editor. Then search for "vt" lines. If they're there, then there is no need to uv map object, because it's already done.

04-19-2012, 08:06 AM
The attached file is the .obj which I can see has many "vt" lines. Additionally the .mtl file shows the surface assignments.

This is the link from the file I bought http://www.turbosquid.com/3d-models/roulette-wheel-3d-model/647850 , what I see in the modeler and what I get when rendered in layout (attached).

There is a reference to 3D MAX at the top of these text files. Does these mean this was built in (and therefore only works with 3D Studio)? This is how inexperienced I am with these files.

Thanks for the assistance.

04-19-2012, 08:09 AM
These are the files that should have been in the last post.

04-19-2012, 08:13 AM
If it has "vt", then open Surface Editor, press T button on right of Color, pick up Projection UV Map, and pick up UV Map.. and image from disk..

04-19-2012, 08:48 AM
You've got me heading down the right path (attached). I've Identified each piece of geometry by coloring the parts and then applying the appropriate UV map from the disk. I don't see a part to accomodate the numbers texture map (which is included).

I also don't understand why the wood has also covered the metal diamond pieces.

I'll probably go into modeler and make these separate parts to apply surfaces as required. Unless I'm missing something you're seeing.

Thank you, this has been a big help.

04-19-2012, 08:52 AM
All this is helpful. I wish I could spend all my production time in LW and really get more up to speed. I wear multiple hats (as we all do) and keep taking 10 steps forward (then move to other parts of my job) and go 5 steps back.

This community has saved my bacon more than once and I'm thankful for all the assistance.


04-19-2012, 08:53 AM
Open reference image in second window.

Better rename surfaces to something making sense- will be easier finding them.

Vertex maps are not stored with obj?? "vn" rows..

If they're you should try using them (pick up from Vertex Normal Map drop-down).

If you don't have Vertex Normal Maps you should probably play with Smoothing toggle and threshold. Depending on surface.