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OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Mon Nov 21, 2011 10:09 pm
by feynman
Hi,
Alias data, tessellated and exported as OBJ, can only be rendered via Maxwell Studio, which works fine and gives good results. But - how can simple surface textures be applied to the OBJ import in Maxwell Studio? You know, textures that "just follow" the surface like in the screenshot below? So far, it seems that texture mapping is available only in solid/projective fashion in MXST? Am I missing something basic here - or is there a recommended workaround for Alias users that want to render with MXST?
Thank you very much in advance!

Re: OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Tue Nov 22, 2011 1:35 pm
by lebulb
Hi feynman
I also work on Alias (automotive 2012).
Normally it should work by default.
Just apply the materials on the geometry.
Unfortunately Alias exports wrong UV in recent versions,
I use Rhino for that, its really boring...
lebulb
PS : how you get this display of UV O.o' never seen that in Alias

Re: OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Tue Nov 22, 2011 3:27 pm
by feynman
Thank you for your quick reply!
It does not work since version 2010 then? That an OBJ export from Alias 2010 and higher can not be surface texture mapped in MXST? Only projection textures are available, which is often just the wrong mapping method. So, if I understand you correctly, you are exporting your Alias files via IGS or STP to Rhino and then save the OBJ from Rhino so it can be mapped in MXST? If that's the only way this is a very archaic method ;)
Then, we're suffering from an Alias bug. In other words, Alias does not export proper UV coordinates in OBJ output? Which is strange since OBJ was developed by Alias/Wavefront a few centuries ago :(
The UV map you see in the screenshot is regular shaders with a surface texture in hardware shade; so it's done manually just to show in forums what I mean.
ps: I have to speak with Autodesk support then, if they can confirm that it's their fault at least. Better to know than stabbing in the dark...
Re: OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Tue Nov 22, 2011 4:44 pm
by lebulb
Hello,
Yes, i export my geometry in iges file in rhino... i'm agree, that sucks.
But its the only solution i found...
sorry my english is bad so screenshot is more easy for me
++
Re: OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Tue Nov 22, 2011 5:30 pm
by feynman
Thanks,
yes a screenshot always says more than a thousand words. I got confirmation from NL that indeed going via Rhino or similar is the only way, because Alias OBJ export lacks UV coordinates. Strange but sadly true.
Re: OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Tue Nov 22, 2011 10:59 pm
by lebulb
Hi Feynman
I have some more time to answer you.
Export uv worked well until version 13 of Alias, i believe. Then, it didn't work, and I'm not the only one who noticed.
I hope at each version they will fix this, but nothing is done. I waste plenty of time because of that.
It is clearly a problem with Alias because the import of obj in other applications creates the same problem.
If you find a solution, let me know.
This work performed under Alias and rendered as mx, there are projections and uv mapping (< made with rhino

)
lebulb
Re: OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Tue Nov 22, 2011 11:30 pm
by feynman
Bon soir,
alors, notre distributeur suédois m'as confirmé "ce que l'exportation OBJ a été modifié au fil des ans". And this is it, end of story. No further explanation given by Autodesk.
A bummer, really, subverting one's very own file format. If I go back to some of my prehistoric SGI files, I see that the OBJs were different. Now, I have the sneaking suspicion that Autodesk did this to inhibit use of Maxwell Render, Bunkspeed Shot, and many other high-end external renders. Although this is silly, because 3DS and Maya are also in Autodesk's portfolio.
Excuse my French ;)
ps: That cannon is really well textured! All through Rhino, I suppose :)
Re: OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Wed Nov 23, 2011 12:01 am
by lebulb
Thank you for those few words
I would not be as suspicious as you, this format is a standard.
I just hope they do something one day.
If I have the courage, I would go on the
Alias forum, but they rarely reply ...
Re: OBJ UV mapping problem - MXST and Alias Automotive 2010+
Posted: Wed Nov 23, 2011 12:08 am
by feynman
Yes, forum useless. Spoke with Autodesk support. They say "that some things have changed". I believe they just don't care. Your Rhino way is the only way.