Exporting a Blender model with textures to the 3ds format ?

Cham · Post #1by **Cham** » 12.08.2016, 18:46

While I have it on my hard drive, I'm not a user of Blender. So I don't know how to export correctly a model from it.

However, there are some nice models of the Curiosity rover on the NASA web site, full texturized. The textures are already PNGs in powers of 2 (1024 x 1024, or 512 x 512). When I export it from Blender, I just get a dull full white model in my 3D app. No textures ! :sad:

So what is the trick with Blender to export a texturized model ? Anyone here knows ? John ?

Here's the model in Celestia. It is pretty rich and detailed. Would be awesome with all its textures !

FarGetaNik · Post #2by **FarGetaNik** » 12.08.2016, 19:59

I just finished my tutorial on cmod editing for Celestia, I hope this helps:
http://celestiaproject.net/forum/viewtopic.php?f=21&t=17427

I don't know much about how 3ds works, maybe the procedure will also work for 3ds, but you need to use texture filenames with less than 8 characters because of its limitations.

Here's the model in Celestia. It is pretty rich and detailed. Would be awesome with all its textures !

We all love our Mars rovers floating in space! :biggrin:

John Van Vliet · Post #3by **John Van Vliet** » 13.08.2016, 01:20

do not use 3ds , this is not the 1990's

export the uv mapped mesh as a obj file
then use cmodview to set the png images
-- the 3d nasa site uses multi layer Photoshop psd images a lot

flatten them and save as a png

Cham · Post #4by **Cham** » 13.08.2016, 01:38

John,

could you be more specific ? When I try to open the obj file with cmodview, it doesn't load (I get an error message).

john71 · Post #5by **john71** » 13.08.2016, 05:08

Try AnyCAD Exchange3D 5.0. My method is (if I have trouble to use a model) a 3ds->obj->3ds->cmod conversion...

Try to convert the model with AnyCad, and then try to import it to Blender...

Goofy · Post #6by **Goofy** » 13.08.2016, 12:53

Please, please, please!
Someone who knows how to do it, please convert this wonderful model for Celestia. :help:

Everytime I show Mars to my students, I feel a most important part of the show is missing, without the possibility to show on the planet this extraordinary machine. :cry:

Please, again!

Goofy (and a lot of young people) :smile:

Cham · Post #7by **Cham** » 13.08.2016, 13:03

It would be very easy to me to edit (optimize a bit) the mesh, and publish a model without textures. But it would be pretty dull in Celestia. We need to use its textures, which look very nice. I'm unable to edit the model with its textures properly applied. :oops:

Goofy · Post #8by **Goofy** » 13.08.2016, 13:31

John71, could you, please? :help:

Thanks a zillion!
Goofy :oops:

Cham · Post #9by **Cham** » 13.08.2016, 13:42

Currently, this is all of Curiosity that I can show to my students ! :oops:

Goofy · Post #10by **Goofy** » 13.08.2016, 13:47

OMG!
In my signature I say that something is better than nothing, but in this case....... :wink:

Goofy

john71 · Post #11by **john71** » 13.08.2016, 14:56

The NASA model is not assembled. If you have it already in Celestia, you have the 3ds or cmod version of it.

Here you can download cmodview:

viewtopic.php?f=25&t=17413&p=134262&hilit=cmodview#p134262

Open it in cmodview, click on certain parts of the model and you can color it.

Cham · Post #12by **Cham** » 13.08.2016, 15:10

John,

the problem is not about colors, it's about getting the textures to work on the model.
The NASA model is assembled (see my first picture above).

In blender, as I have shown above, ALL the textures are already applied correctly (in Blender).
Exporting that model in a format that could be used in Celestia is the problem. I don't know how to keep the textures attached to the model.

3ds files CAN have textures.

Post #13by **selden** » 13.08.2016, 15:15

John71,

I'm not sure what you mean by "not assembled".

It looks complete to me.

My procedure was
import into blender
export as obj
import into Anim8or
delete purple "do not render" boxes
export as cmod
create folders models and textures/medres
convert .png surface textures to .jpg (the pngs include alpha channels which cause rendering depth problems in Celestia)
create ssc
view

Edited to add:
the zip file is a Celestia Addon. It's so large because it includes the original .blend model along with the intermediate .obj and .an8 models.
My SSC just has it floating in space so I could see if it looked OK. Someone will have to provide an appropriate SSC which places it on Mars.

Cham · Post #14by **Cham** » 13.08.2016, 15:32

Wow Selden ! Thanks a lot !

Could you do the same with the dirty version ? I think it should look nicer.

Or do we just have to change the textures ? (I'll try in a few minutes).

Post #15by **selden** » 13.08.2016, 15:40

If the texture file names are the same, all you should need to do is replace them.

Cham · Post #16by **Cham** » 13.08.2016, 15:45

Selden,

the textures files have the same name, but "tex_03.jpg" appears to have some differences.
Replacing the files works.

Also, your model doesn't use all the textures correctly : the wheels are without textures, and I think they should have some (especially the dirty version).
The plutonium box should also have some textures.

I didn't noticed the normal map working. Something is fishy here.

And please check again the wheels : there should be several squares holes on them. I can see them in my modeler.

Added after 5 minutes 7 seconds:
Sorry, no holes on the wheels. I don't know how I saw them ! :oops:

Maybe a transparency effect ?

Added after 21 minutes 11 seconds:
I managed to fix a few parts on BB8, .. err, Curiosity ! :smile:

It need more testing and tries, because the normal map doesn't seem to work :

This version looks already pretty in Celestia

Added after 22 minutes 2 seconds:
Ok, I found a way to make the normal map effect to work. I just need to fix a few other things before a release.

Added after 33 minutes 39 seconds:
That's it ! I think I got it right. Because of the normal texture and specularity, the cmod file is much bigger : 7 MB ! :spy:

The normal effect and specularity is very subtle, tough.

Two views :

Added after 18 minutes 20 seconds:
There is still a problem with the wheels. In my modeler (without any textures), I can clearly see the holes on the wheels of the dirty version :

: wheels.jpg (18.35 KiB) Viewed 19113 times

But the model from Selden (clean version), that I fixed for several textures, don't have holes !

Selden, please, could you convert the dirty version for me ? I'll do the textures fixing.

john71 · Post #17by **john71** » 13.08.2016, 17:33

Selden: I downloaded from http://nasa3d.arc.nasa.gov/detail/mars-rover-curiosity the 29.04 mb stl file and only 3d parts were in it...like body, chemcam, legs etc..

Added after 6 minutes 29 seconds:
By the way, Selden, your model looks spectacular in Blender!!! :clap:

Post #18by **selden** » 13.08.2016, 19:59

John,

That's because you downloaded the .STL version. It is intended to be used as input to a 3D printer. Its parts have to be separate so the printer can create them. The .BLEND versions are at http://nasa3d.arc.nasa.gov/detail/curiosity-clean and http://nasa3d.arc.nasa.gov/detail/curiosity-dirty

Added after 10 minutes 9 seconds:
Here's MSL_dirty in blend, obj, an8 and cmod formats. It's not configured as an Addon.

Cham · Post #19by **Cham** » 13.08.2016, 20:14

Thanks Selden,

I'll study this version.

Added after 11 minutes 33 seconds:
Selden,

the new model has several problems. Maybe flipped normals. I don't think I could fix these.

Post #20by **selden** » 13.08.2016, 21:47

Cham,

Unfortunately, there are many faces which have flipped normals, too many for me to correct manually. Some of them won't even let me select them. :(
Unfortunately, Anim8or's "fix normals" option is greyed out. :(
I'll ask on the Anim8or forum to find out if there is any way to re-enable it.

Here's a screengrab showing the situation: Yellow faces have their normals correctly pointed outward, Blue faces have them incorrectly pointed inward.