Celestia Forums

Hello all!

I've been toying with 3DS Max for a few years and recently stumbled across Celestia. I've never really done much with UVW mapping and low-polygon meshes but this program provides a great opportunity to do so! But I'm having difficulties with multiple textures on a single mesh.

I tried a multi-subobject material first - guess that doesn't work with celestia?? This is probably easy, but for some reason it's giving me fits

Here's my process/example: create a cube, convert to editable mesh, select first face, apply UVW planar map to that face, apply texture, collapse the stack, repeat for the remaining faces. The textures are 6 (different colored) jpg's, sizes are 256x256.

Everything looks fine in max, but in Celestia, I get a cube that is a solid color (usually the last color I applied). It feels like I'm just overlooking something simple....

What am I doing wrong? Any help is much appreciated!!

BTW: awesome program!! I've been lurking the forums for quite a while now and finally decided to speak up

Doh!

I finally figured it out. I was forgetting to detach each section of mesh that will have a different texture. Works like a charm now.

As a side question: What aspects/parameters from 3DSmax's materials can be used in Celestia? Obviously the diffuse slot is used and I know that the Opacity value is functional - but are there any others? Can opacity maps be used? Just wondering what can and can't be done

Also, are there any plans to implement "multi-subobject materials" in Celestia?

Thanks again!

forgot to login...

you wrote

I was forgetting to detach each section of mesh that will have a different texture

what is detach? i also have the same problem. can yo uexplain me? im not using 3ds max, but i think that in anim8or there should be a similar option.
can you help me?

"Detach" is an option in 3DS max in the editable mesh modifier panel.

Basically it just detaches a selection of polygons into a separate object.

In my cube example, I wanted to export a cube that would have 6 different textures (one for each side) in Celestia. So i first created 6 different colored .jpgs for testing.

here's the steps in 3DSmax to do this:

1. create cube
2. convert it to an editable mesh
3. at the polygon level - select one side of the cube
4. click "detach"
5. repeat for the other sides (you should now have 6 separate objects)
6. create 6 separate materials in max with the respective texture maps in the diffuse slot
7. apply first material to first side
8. repeat for the remaining sides
9. apply a seprate UVW map to each object (you will have to play with the UVW properties to get the texture aligned properly)
10. collapse each object (not sure if this step is necessary)
11. select all objects
12. export selected

It all worked great for me.

Basically whats happening is you are creating, texturing and mapping 6 different objects that just so happen to look like a cube. But when you select all the objects and export to a single .3ds - it is treated as one mesh. I noticed this when I imported some of the models that come with Celestia.

Hope this helps!

Anonymous wrote::? Doh!

I finally figured it out. I was forgetting to detach each section of mesh that will have a different texture. Works like a charm now.

As a side question: What aspects/parameters from 3DSmax's materials can be used in Celestia? Obviously the diffuse slot is used and I know that the Opacity value is functional - but are there any others? Can opacity maps be used? Just wondering what can and can't be done

Specular color and shininess (specular exponent) may also be set. If there's an interest, I can also add emissive color.

Right now, opacity maps will only work when the opacity is less than one. The 3DS code is due for a reworking soon, and I'll address this then.

Also, are there any plans to implement "multi-subobject materials" in Celestia?

Possibly . . . This adds a significant amount of processing work when loading a model. In fact, a lot of this work should be done anyway in order to optimize rendering of the models. I'd like to add support for a more 'hardware-friendly' 3D file format that can be loaded very quickly. The preprocessing work should be done a single time when converting the model, not everytime that it's loaded.

--Chris

jabels, thank yo ufor the help!!! it works!
i told you that i dont have the 3DS, but i have the anim8or. but its not a problem, i have found the detach function. now i can finish my fisrt model. i had a problem with the colors, but with this i think that its done.

the only problem that i cant solve is the orientation.

maybe some one can give me the code:
i want an object like an UFO flying with his botton part watching the surface. and also to rotate like a ufo.
i couldnt do it yet, i could do one thing or the other, but not the two at the same time.

Hi jables,

Look at this post:

http://www.celestiaproject.net/forum/viewtopic.php?t=1788

Bye Jens

is it possible to put a png texture with alpha chanel on a mesh??? to use like a glass window and to see trough it?

Chris & Jim: thanks for the info! Much appreciated!

ElPelado: if not, you could always model the window or "cut" it out of the existing mesh, as a separate object. Then just create a glass material and adjust the opacity setting to the desired effect.