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UV/Ptex question


AbnRanger
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Someone asked what a good UV Unwrap plugin or program was over at CG Talk in the 3ds Max thread. I happened to throw 3DC in there, as I'm convinced it's top shelf in this area, especially with Ptex. One of the regulars there posed this question, and it's a bit beyond me to know what he is talking about in reference to needing to be able to retain explicit vertex normal data. Can one of the more experienced 3DC Grand Pooh Bah's chime in, and disperse some wisdom for us on the matter? :)

Here's the quote:

Problem is I am doing aircraft with paint schemes that need to wrap properly. Basically planar mapped from the side, but without the pixelation that happens as it crosses over the top and bottom. That and trying to unwrap and paint 10 million+ triangles in any app is no fun, especially across so many objects, or even on low object counts (ie, millions of triangles per object). It is much quicker to create the schemes in a 2d app and then just have simple unwraps. That and I need to be able to retain explicit (vertex) normal data. Which I am guessing the 3d paint apps don't support, and there are problems trying to transfer mapping data from one object to another when explicit normals are involved. So until I can figure out a solution to that, I can't go outside of 3ds max.

So unfortunately its not just one or two things that is the problem. :/

-Eric

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Ptex wouldn't help because there's just too many polygons. As far as I know Ptex is really suited to low poly (quad) models as there needs to be a texture tile for every polygon and each tile needs a border. So with 10 million polygons/tiles the texture size would be monstrous.

Could they not retopo or decimate their model to produce a lower poly (uv mappable) version and then take it from there?. They can then bake any lost detail into a displacement or normal map.

10 million polys for an aircraft. They must've modeled all the rivets! :blink:

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Basically what splodge said. I would decimate/reduce poly counts, use this proxy for the painting and then just bake the difference to the high res mesh. Ptex wont help with such a high res mesh.

And seriously, that is a really high poly count for just an aircraft. Unless he modeled the inside, outside, and all mechanical portions... That just seems too high to me. :pardon:

As for his unwrapping method it sounds like he just wants a cylindrical map. From what I read there I'm guessing he is using planar projections in Max and doesn't want to do something else. He would get much better results by actually doing something a little more advanced like creating a UV map, lol. Has he tried 3DC at all? I've no doubt it would work. Even likely with his high poly model (just don't smooth or subdivide it). He could hide the other parts as he paints in the sub-object panel.

3DC does allow for vertex data to be unchanged. Just don't smooth the object upon import and the vertex data will remain unchanged. ZB does smoothing automatically when you subdivide, as that is the nature of the application. Since it cannot paint directly like 3DC or the Maxon program (the name eludes me right now), it can only do poly painting, where as you need high poly counts because the color is attached to the polygon and not directly painted to the texture map.

Anyway now I'm just rambling. Point is: He has lots of options, it just sounds like he hasn't tried and is speculating.

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It's probably raw triangulated meshdata exported from some highend CAD app, which explains the highpolycount and ofcourse multiple meshes with extreme detail. It would not work well importing a 10+ million polymesh into 3DC, it would choke instantly on such a big model.

/ Magnus

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Hey Magnus.

Have you tried to load something in 3DC with such a high poly count? I'm just guessing here... But you probably didn't. I however, did.

I just spent some time subdividing an already very high poly object (Again, something this high poly is totally useless in actual production, why on earth would you not decimate it is beyond me) up to the ridiculous and absolutely unneeded almost 4 million polygons. I would have subdivided higher, but I got bored sitting there waiting for LW to subdivide my object parts. Just watch the video, you'll see how "slow" 3DC is with almost 4M polygons. :rolleyes:

You could probably import something with 10M polygons, but honestly I didn't want to waste my time subdividing in LW because it takes forever. Also keep in mind that 3DC can import a "big mesh" up to 16M polygons.

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You assume that i didn't try it ? hmpf. I have tried it numerous times, i tried importing objects with as little as 50,000 polys and 3DC chokes with even such relative lowpoly meshes. You can't work with them, try texturepainting and you have some serious lags. What's the point of importing a mesh into 3DC if you can't do anything with it..

Then again, you probably have a much better monstermachine than i do so it all runs supersmooth and in realtime for you.

/ Magnus

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I was the one who originally posted that over at CGTalk, thanks for inquiring here Don. I am dealing with high end CAD data (some of the data is 15,000+ assembly and part files) that is converted in 3ds max using nPower Translator. This allows me to dynamically control the tessellation. The advantage of staying in Max means I can changing the tessellation and retain the mapping data done through UVW Mapping. Like I said in the other thread, there are a lot of problems/questions that needed to be figured out before I can move forward with any new option.

Which formats I/O are supported in 3d coat with explicit/vertex data and 10+ million triangles? I can't say I like what I am reading for the Big Mesh Import:

Import a large mesh (up to 16 M). This function requires two meshes; a low-poly reference mesh and a high poly mesh. Both should have the same non overlapped UVset. First import the low-poly mesh into scene using the usual import dialog, then load the high poly mesh using this option.
and the Export option descriptions:
You will be prompted to select either a low-poly mesh, or a mid-poly mesh with 30k to 80k polygons and the normal map.
Can I import, paint and export only the high detail 10+ million triangle data? Can I easily project paint schemes through the data so it is symmetrical on both sides? Does the border width also apply to Spline/B-Spline? Could the border width be used to fill outside the shapes of the Splines?

Those are the questions for now,

-Eric

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Can I import, paint and export only the high detail 10+ million triangle data?

I don't know of any program that could automatically create a UV map for a 10 million poly model. Or rather - my patience or system's memory always runs out before a program has completed the task. :)

Cinema 4D can't even create a cubic UV map for 50000 polys without running out of memory on a 4 gig machine.

Perhaps Maya could do it.. but I doubt it. Up until recently those kind of programs couldn't even display a 1 million poly model without fainting. Not because they're crap, but simply because they're not designed to work with such detailed models.

What do you plan to do with the model when it's painted?. If you're only gonna use it to produce some 2D images then maybe you could vertex paint it instead? This way you won't need a UV map. And no seams or pixelation! :)

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I was the one who originally posted that over at CGTalk, thanks for inquiring here Don. I am dealing with high end CAD data (some of the data is 15,000+ assembly and part files) that is converted in 3ds max using nPower Translator. This allows me to dynamically control the tessellation. The advantage of staying in Max means I can changing the tessellation and retain the mapping data done through UVW Mapping. Like I said in the other thread, there are a lot of problems/questions that needed to be figured out before I can move forward with any new option.

Which formats I/O are supported in 3d coat with explicit/vertex data and 10+ million triangles? I can't say I like what I am reading for the Big Mesh Import:and the Export option descriptions: Can I import, paint and export only the high detail 10+ million triangle data? Can I easily project paint schemes through the data so it is symmetrical on both sides? Does the border width also apply to Spline/B-Spline? Could the border width be used to fill outside the shapes of the Splines?

Those are the questions for now,

-Eric

Thanks guys...I'm thinking baking a normal map in Max, from the high res to a lower res copy. At which point you can import the lower res model in along with the normal map. I'd at least run a little test, before you do that, by importing the hi-res mesh of a portion of the model (like the fuselage) and see how well it works. And yes, you have the ability to paint symmetrically.

You can hit the "S" key and a dialogue pops up allowing you to toggle the symmetry plane and turn it's visibility on or off.

http://www.3d-coat.com/texture-painting/

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You assume that i didn't try it ? hmpf. I have tried it numerous times, i tried importing objects with as little as 50,000 polys and 3DC chokes with even such relative lowpoly meshes. You can't work with them, try texturepainting and you have some serious lags. What's the point of importing a mesh into 3DC if you can't do anything with it..

Then again, you probably have a much better monstermachine than i do so it all runs supersmooth and in realtime for you.

/ Magnus

Yep, It was a safe assumption. Obviously you need to upgrade your machine. Mine machine is more then 3 years old, other then the video card (which has no bearing on anything other then OGL display and CUDA which only affects voxel sculpting).

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I was the one who originally posted that over at CGTalk, thanks for inquiring here Don.

Welcome to the forums! :)

I am dealing with high end CAD data (some of the data is 15,000+ assembly and part files) that is converted in 3ds max using nPower Translator. This allows me to dynamically control the tessellation. The advantage of staying in Max means I can changing the tessellation and retain the mapping data done through UVW Mapping. Like I said in the other thread, there are a lot of problems/questions that needed to be figured out before I can move forward with any new option.

Since you can control the tessellation, why not scale it down to a more manageable amount of polygons, paint on your low res version and then bake the maps to your high res?

Which formats I/O are supported in 3d coat with explicit/vertex data and 10+ million triangles?

At the moment I use .lwo, it seems to keep all vertex data intact.

I can't say I like what I am reading for the Big Mesh Import:and the Export option descriptions: Can I import, paint and export only the high detail 10+ million triangle data?

I personally haven't had the need to use this method. Most of my meshes are small enough (well, certainly smaller then 10M+ lol) I don't need to use the "Big mesh" option.

As far as using the 10M object, if it already has a UV map then it shouldn't be a big deal. If 3DC has to auto generate the UV map, then it may take a while and you will need to refine some areas of the UV map (I've sometimes with very large meshes get a little overlapping in some areas - But this is why I manually lay out UVs).

All I can say is - Try it out. I assume you have the demo? Give 'er a go. :) I've successfully imported a 4M poly mesh with no UV map, and painted on it. So long as you be sure to organize your object in a logical manner with the sub-objects panel (Been a long time since I've used Max, but I believe you can organize things in there as sub-objects - I would do this before bringing it into 3DC). The only problem I had was the wait time while it created the UV map w/ some overlapping UV sections, and a good bit of slow down on my strokes if I didn't hide sub-objects. With 10M, I think it would slow down quite a bit if you didn't have huge chunks hidden from view.

Can I easily project paint schemes through the data so it is symmetrical on both sides?

Yes, you can use symmetry or use a number of symmetry/copying tools to copy portions of the plane to other areas if you prefer this to standard symmetry.

Does the border width also apply to Spline/B-Spline?

Yes.

Could the border width be used to fill outside the shapes of the Splines?

I don't think this is possible. That would make a good feature request. :)

Anyway, like I mentioned previously, I wouldn't paint on so large a mesh in the first place. I would use a lower poly version for painting, then bake the details.

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Yep, It was a safe assumption. Obviously you need to upgrade your machine. Mine machine is more then 3 years old, other then the video card (which has no bearing on anything other then OGL display and CUDA which only affects voxel sculpting).

I'm not sure it's safe to assume that. It all depends on how you're importing your model. For example if somebody is importing a high poly model and wanting 3D Coat to create a UV map for their model then they're going to have a long wait despite having a quad core CPU.

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I'm not sure it's safe to assume that. It all depends on how you're importing your model. For example if somebody is importing a high poly model and wanting 3D Coat to create a UV map for their model then they're going to have a long wait despite having a quad core CPU.

I imported the 4m poly object with no UV map (other then my creating 4 blank ones for use later), I have a quad core Phenom 9500 (remember, the first one AMD put out that isn't all that great?) and 8GB DDR2 800. It's not a killer machine, by any means. It imported and created 4 different UV maps (based on the blank ones I previously created), it created all 4 maps from 4m polygons.

I think that alone should indicate that 3DC is capable of it, even though I don't recommend it at all.

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I imported the 4m poly object with no UV map (other then my creating 4 blank ones for use later), I have a quad core Phenom 9500 (remember, the first one AMD put out that isn't all that great?) and 8GB DDR2 800. It's not a killer machine, by any means. It imported and created 4 different UV maps (based on the blank ones I previously created), it created all 4 maps from 4m polygons.

Try importing a 4 million poly model and asking 3D Coat to create a new UV map automatically from fresh (not based on previously created UV map).

...and I'll see you next week!

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I was the one who originally posted that over at CGTalk, thanks for inquiring here Don. I am dealing with high end CAD data (some of the data is 15,000+ assembly and part files) that is converted in 3ds max using nPower Translator. This allows me to dynamically control the tessellation. The advantage of staying in Max means I can changing the tessellation and retain the mapping data done through UVW Mapping. Like I said in the other thread, there are a lot of problems/questions that needed to be figured out before I can move forward with any new option.

Which formats I/O are supported in 3d coat with explicit/vertex data and 10+ million triangles? I can't say I like what I am reading for the Big Mesh Import:and the Export option descriptions: Can I import, paint and export only the high detail 10+ million triangle data? Can I easily project paint schemes through the data so it is symmetrical on both sides? Does the border width also apply to Spline/B-Spline? Could the border width be used to fill outside the shapes of the Splines?

Those are the questions for now,

-Eric

You would not paint or uv map cad data objects all at once or even without optimizing for a 3dsoftware package.

I did some car catalog for honda and the cad data from honda was of course too heavy. No way would any machine or any software be able to handle that data in the viewport without splitting up the objects or even splitting the scene files. Lw choked at loading, maya couldn't render it, max was a bit bearable. 15 million real polys just for the body. 5 million per wheel. Unhiding two wheels crashed max. Lol!

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