UV Mapping a High Poly

ralusek

am i fucked? 1.2 million polies. how might one go about texturing such a work?

i have zbrush and blender available for usage, and have mats/colors on the model in zbrush. as far as i understand, you cannot map uv's in zbrush, is that right? i would love to map in low subdivision and use that for high poly...but i don't know if this is a tool that exists.

opening an obj of 1.2 million will basically crash blender, so hopefully there is a tool in zbrush that makes this a wee bit easier.

sorry if this is either absurdly common or something very difficult, but any insight on the topic would be great

NAIMA

I am not expert but I suggest to split the model into material pieces , like arm , head etc if is a human model for example then apply some uvmapping tools from 3dsmax if u use that or maya , I dont think there is something similar in zbrush ....or alternatively you can try the deep uv tool but I didnt find it so better than the actual uvmapping tools already present in 3dsmax....

SpeCter

You could try the decimation master for Zbrush it reduces the polycount with almost no visual changes.

ralusek

hmm, i will look into that, sounds interesting

MoP

If your model is a ZBrush mesh, you can UV-map your lowest subdivision level in an external app, then use the Import button at that sub-d level to import the UV-mapped mesh.

Personally I UV-map all my "cage" meshes before starting to ZBrush even if I'm not sure I'm going to texture it - UV-mapping a simple cage mesh takes 10-15 minutes, the UVs don't have to be optimised (just keep seams to a minimum) and it means in the end you can do whatever you want with the texture on the highpoly.

Hell, you could even use the ZBrush "AUVTiles" or "GUVTiles" buttons at the lowest sub-d level to apply quick and dirty UVs, then bake your polypainting to a texture based on those.
The texture bake won't be editable in photoshop due to the auto UV layout but it will display correctly when applied to the model in any other app.

fullofclovers

You could do what MoP suggested and then import that into your app of choice and bake your polypaint to a lower poly count mesh that has been UV'd correctly. That way you have your diffuse in tact to be easily editable in Photoshop if need-be.

ironbearxl

Drop to the lowest level in Zbrush, export it to Blender and make your uv's, then re-import to Zbrush.

If you're on a 64-bit windows machine, try Blender 64 win, I've been able to import + 3 million poly meshes easily.

Taylor Hood

Their is this thing.. called normal maps.

ralusek

thanks MoP. so it sounds like i'm going to be losing a lot of my detail doing this. if i export low sub-d obj, map it, and import it, my only options for texturing high poly are just subdividing to high poly level and then redoing the finer sculpting, correct? i couldn't load the map to a comparable division of my old tool, could i?

i mean i definitely get that i need to take care of UV business from now on long before i get into this kind of detail, but i don't just want to bail on this guy .

and LoM Chaos, i'm not talking about normal mapping for low poly bud, i want to texture my high poly. EDIT: and more importantly, UV map it. because as far as i know, i can't map UV in xnormal either. without map, i can't bake it =/

EarthQuake

ralusek: i think by uving and re-importing your cage mesh you can actually retain the high levels.

Taylor Hood

Okay Ralusek, but why do you want to try and texture a hugley dense model? I'm not really informed about doing anything that. Is it for a film or game?

guangh69

I think you shuold use Unfold 3d.I really like it!A magic tool for mapping UV.It can unfold miliions of UV in seconds with high quality.Just wonderful.Then import your model into Bodypaint or photoshop to panit texture.I always do like this.Ah ha.I had demo version of Unfold 3d.If you need,I can send it to you.Or you can download it here.A sword to UV!http://www.supfree.com/soft/soft.asp?v_id=45027

MoP

Ralusek: As EarthQuake said, if you use the method I described then you don't lose anything. You just go back up to your highest sub-d level in ZBrush and all your polypainting and sculpting will still be there, unchanged. Only now your mesh will have UVs!
At which point you can bake your polypainting to a good laid-out texture.

ralusek

thanks guangh69 i'll look into it, has anyone else heard of that?

and LoM, i mainly want to normal map and bake it. because i've already polypainted it, and i need a normal map regardless. i just can't do either without it uv mapped

ralusek

MoP wrote: »

Ralusek: As EarthQuake said, if you use the method I described then you don't lose anything. You just go back up to your highest sub-d level in ZBrush and all your polypainting and sculpting will still be there, unchanged. Only now your mesh will have UVs!
At which point you can bake your polypainting to a good laid-out texture.

perfect! thanks

Reverenddevil

Are you sculpting a character or a hard surface object? The way I do it and others at my company (for organic and some hard surface objects) is we will model out a quaded out basic mesh of what we want depending on what it is if its more organic or not. We will then make sure it divides in zbrush properly and sculpt away not caring about silhouette or anything else just making sure it works.
I will then go to my lowest or second lowest sub division and export that as my low poly. I unwrap that object since it is the same shape as my high poly I dont have to worry about things not matching up. I will then pro optimize the mesh or you can use moo tools to get it to a the tri limit I have to have. I then export both the hi and low to Xnormal and bake my maps, crazy bump whats needed and texture then throw into game and let the magic happen.

ralusek

cool man. ya i'm sculpting a character, i started with low poly quad mesh, subdividedx6 to 1.2million, and sculpted all details etc. i still have low poly, and just needed to add a UV map for the high poly to xnormal, bake etc.

what MoP suggested worked great though, no idea that i could import an obj into a lower subdivision and have the UV applied to the high poly as well.

Xoliul

Am I reading this correctly, you are under the impression that you can't bake high to low without your highpoly having a UV map? Sounds like you've never heard of projection baking...

G3L

What I'll do usually is use xNormal. Export out the low poly and UV map that, take high poly and export that out as well but don't touch that after you export it.

Once the low is UV'd, then take both OBJ's and bring them into xNormal and get your normals from there! Plus AO Map if need be as well. That's the workflow I usually take when taking or doing meshes in Zbrush and them needing some UV's.

EarthQuake

Read the thread guys, he's not doing anything with a lowpoly model. He wants to texture his highpoly sculpt(likely for renders etc).

holygon

Try a program called 'Roadkill' it's free.

Basically you just select on your seam where you wish to weld/cut and it will automatically adjust your UVs to minimize stretching, it also has a programmatic texture that will visually show you the stretching with colors.

Personally I don't use Roadkill anymore, instead I use the Roadkill plugin for Maya 2009, and I have to say it works fantastically, and I imagine the automated-ness of it would make your life easy for a hi poly unwrap.

binopittan

EarthQuake wrote: »

Read the thread guys, he's not doing anything with a lowpoly model. He wants to texture his highpoly sculpt(likely for renders etc).

maybe..

ralusek wrote: »

and LoM, i mainly want to normal map and bake it. because i've already polypainted it, and i need a normal map regardless. i just can't do either without it uv mapped