What Program Creates MOHO friendly .OBJs?

Visions of Domino · Post by **Visions of Domino** » Fri Feb 24, 2006 4:01 am

I'm trying to import an .obj file (1.8MB), and it simply freezes on me for several minutes, and when it imported, it is imosible to work with it as it is really really slow. Oh, and it imports black and white.

So, I'm wondering if there is a free 3D program I can import my .OBJ file into and export to a MOHO friendly obj file. Is 1.8MB too large a file?

EDIT: The files i'm using are created with LDraw(.org).

Thanks,
VoD

EDIT: Ok, it looks like if I resize them in MOHO (for some reason they import HUGE), then everything goes smoothly. Now I have to find out why it doesn't keep the colors at all.

jorgy · Post by **jorgy** » Fri Feb 24, 2006 10:31 pm

I'm not familiar with that program, but there are three aspects to colors that are stored in the obj format: diffuse, ambient, specular, emission. Right now, only diffuse is understood by moho. This is because moho isn't a 3D program, and doesn't do any kind of lighting or lighting effects. So you will need to investigate how your program stores it's colors and "bakes" them in, and see if it is possible to store all the color information as "diffuse" info.

Also, one other thing with your scaling problem: there is a script that comes with moho, under the menu item "Scripts" -> "3D" -> "Auto Scale" that will automatically scale your obj for you.

Hope this helps,

jorgy

bupaje · Post by **bupaje** » Sat Feb 25, 2006 12:46 am

I had a problem with Carrara -the the material file (ends in .mtl) did not have the right path to the image file -actually had the wrong extension- so you might check that; it can be opened with notepad and just make sure that the path and file name of the texture that should have been exported is correct. Just to cover all the bases ...

Visions of Domino · Post by **Visions of Domino** » Sat Feb 25, 2006 1:32 am

Thanks Jorgy, the resize script works great.
I'm trying to find out how to deal with the Diffuse export. As a last resort, what program would you recommend to easily colorize my 3d models and export with MOHO friendly settings. So far I can't make head nor tale of Blender...

@bupaje - can't find a reference to an image file in the mtl file.

bupaje · Post by **bupaje** » Sat Feb 25, 2006 2:25 am

Then maybe no material is applied? I know that some programs allow you to assign a color but this is not a texture. There needs to be either a 'export color as texture' option when you export or you'll need to actually choose and apply a texture to the diffuse channel. Someone correct me if I'm wrong ...

Here is what one of the mtl files looks like from my object, you can see the image name in the last line ...

Code: Select all

newmtl Shader
 Ns 163
 d 1
 Ni 0.001
 illum 2
 Ka 0.2 0.2 0.2
 Kd 0.733333 0.741176 0.745098
 Ks 0.25 0.25 0.25
 map_Kd brickwall_1.bmp

Visions of Domino · Post by **Visions of Domino** » Sat Feb 25, 2006 9:32 pm

no, no image reference, because I believe I'm only working with solid colors, not textures. But I still can't any settings to set a diffuse channel. I have tried several programs with no luck. None give me an option to set the color to anything.

bupaje · Post by **bupaje** » Sat Feb 25, 2006 11:48 pm

Ok, then you need a texture. Obj files do not normally contain color information for faces they can reference the external mtl file that tells it where stuff is stored. They could export color information but I don't think that Moho reads that info (correct me if I am wrong) -at leats I had never been able to import an obj with a color assigned to the face unless I checked the option to export that color as a texture - the 3D program takes the color and actually makes a texture.

Does the program you mention allow you to texture and object? If so why not just create a simple cube and a solid color texture and see if it exports correctly.

7feet · Post by **7feet** » Sun Feb 26, 2006 8:33 am

The Kd (as in the line in bupaje's example, "Kd 0.733333 0.741176 0.745098") is the designation of the RGB values of the diffuse channel.

Here's a link to a description of the basic MTL file format (first one I found quickstyle).

As I believe Visions of Domino was referencing, Moho only pays attention to the Diffuse color in a material, but that should be there when you import to Moho (sorry bupaje). Almost everything that I've used in Moho has been built (or, if off-the-shelf, rebuilt) in Wings3D, which is a pretty decent (open source, cross platform) modeler and easy to assign basic materials to faces.

When you get it to work, you should check out my Simple OBJect Shading script(http://www.lostmarble.com/forum/viewtopic.php?t=1446), lets you bake shading from a "light source" onto OBJects inside of Moho. Pretty nifty for geometrical objects, if I do say so myself.

I've had no luck with textures, but there are the occasional bits I'm awful stupid with, just some sort of mental block. But Moho does seem to smooth objects with a texture assigned, where that doesn't seem to happen at all with just color materials.

bupaje · Post by **bupaje** » Sun Feb 26, 2006 5:13 pm

but that should be there when you import to Moho (sorry bupaje).

... and then there's the right answer.

Interesting because when I was having my problems importing from Carrara I managed to get the textures eventually but not the colors. I must have been doing something wrong as well if the info is in there.