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claws_33
02-14-2006, 04:42 AM
could someone please give me some help on how to export my model into zbrush and then back? i've tried but everytime it ends up...well not working, and none of the tutorials have helped at all. i'm currently using lightwave 7.5, and i'd truly appreciate any help! thanks

Alonzo
02-14-2006, 05:06 AM
hallo,

i never had lightwave 7.5, but in 8 (.5) you can export your model to *.obj
this *.obj you can import to zbrush... if there are still problems please tell me ;)

greetz
Alonzo

PerfectLine
02-14-2006, 05:46 AM
A couple of things have to be done before exporting a model to Z-Brush if the model is going to be used in Lightwave. You'll need a few plug ins like a 16bit tiff loader, Lynxs displacement plug in or the zwave plug in.

There are two ways that I know of. The one in this post is using displacement maps. The other is normal maps.

-----------------------------

Lightwave export steps.

1. Model the geometry in Modeler so that the major areas are as cloe to teh final as possible for best results. Now this does not mean you have to model every little detail but its best if your character has a tail to model the tail in Lightwave instead of just brushing in the tail geometry from a flat surface. THis would cause numerous displacement map problems later. Try to get the major portions as close as you can.

2. Next, UV maps must be defined in Lightwave before exporting to z-brush. You can successfully do it other ways but the best results are achieved when Lightwave defines the UV's first.

3. The Lightwave object will be leaving to z-brush as an OBJ. Z-Brush does not support LWO's natively.

4. Since the Lightwave object becomes an OBJ you must triple the geometry. If you do not then the conversion process will do it for you but you may get some tripled geometry you do not want. Best make sure you do the tripling yourself.

---------------------------------------

Z-Brush import steps.

1. Upon importing your OBJ you'll want to define the color and displacement texture resolution before doing any brush work. I would start with 2048x2048 or higher. Make sure these are setup before brushing begins or you may not get the resolution or projection you want or even end up with non matching textures when going back into Lightwave.

2. Once you have your textures set you need to "store a Morph target" This will tell z-brush to take a picture of your low resolution mesh so that when you add further subdivision levels it can go back to lower resolutions again for export back to Lightwave. The idea here is that you...

a. Start with a low poly mesh

b. Set your displacement texture resolution

c. Store the low poly mesh "store morph target"

d. Begin brushing in displacement geometry that will be added to the displacement texture you set up in step "B"

3. Now that you have the textures and low poly mesh setup you can now bush on displacement details. You can upres the model by pressing "subdivide" to further add more geometry to manipulate.

4. Adding small details like wrinkles are done with alpha brushes that will be added with "projection master"

5. Then you can add color to your model and this will be added to the color texture seperate from teh displacement texture. color to taste. This is an aquired skill like learning photoshop. Painting on a 3d model is not something you just learn on the first try. Keep at it and you'll learn what z brush likes and dislikes.

Once your z-brush model is all the rave with wicked details, bulgeing veins, dirty teeth, and anything else you might need iit is now time to go back to Lightwave.

6. Save out the Displacement map which should be a 16bit tiff, if its not a 16bit tiff you may not have the nice small details. Also export your color texture as well, a TGA should do fine. YOu can flip the images vertically either in Z-brush or do it later in Photoshop. The export or import flips them for some reason. Don't ask me why.

7. Return you model to the low poly mesh "morph target" and export it as a different OBJ file then the one you brought in.

----------------------------

Back in Lightwave

1. Open the model in modeler. It should similar to the mesh you exported, maybe slightly different due to the z-brushing.

2. Press "tab" to make it a subdivided model and save it out to a LWO file.

3. Open the LWO file in Lightwave....don't worry the magic isn;t applied yet...it still a low poly mess right?

4. If you loaded the 16Bit tiff loader (just a plug-in that you add) you should be able to open your displacement map. Load the displacement into Lynx's displacment plug in and make sure when you choose the displacement texture that you also use the UV projection you defined before exporting from Lightwave to Z-Brush. If you don't you'll end up with a mess. CHoose "UV" projection and then in the uv list should be your defined UV's that will line up the displacement map properly. Also, if its weird you may have not yet flipped it vertically yet.

If it looks like the model you made but is blurry in detail or is fat you have two thinsgs to tweak. First is the Lynx's plug in size parameters and second is the subdivision level you are using. Lightwave defaults to level 3. Often you have to go much higher to match the details in z-brush. Sometimes I end up with a million poly model. Which has had me wanting 64bit Lightwave for about a year ;)


5. Do the same for your color map in the color channel as well...pick the UV projection. Also its good to add the displacement map to the bump map as well to get the small details.

http://img124.imageshack.us/img124/5349/zbrush12pw.jpg

Nemoid
02-14-2006, 06:21 AM
Cool process !

I'd add that, if you don't want to UV your model in LW, you can do that in
ZB.especially valid if you paint your textures entirely l in ZB.

you can use adaptive UV )in the texture menu palette) then paint your maps
then you export your .obj

there's a cool plugin called Zwave which allows you to load the UV from the .obj you saved in ZB and transfer it in the previous Lwo. so, if u had , lets say, endomorphs or other maps stored in your Lwo yet, u can have both Lwo with ZB UV.

the fine thing is you get quite undistorted UV,a nd displacement is a bit better that way.

Note : the ZB uV is clearly not like a manual unwrapped one. its actually unusable to paint it in photoshop. but now, ypou have also zapp link ZB plugin which allows to work with ZB and Ps through Proj master.

Polystress
02-14-2006, 07:48 AM
7. Return you model to the low poly mesh "morph target" and export it as a different OBJ file then the one you brought in.

What this step for?

Thanks

matt-ksp
02-14-2006, 02:46 PM
"I'd add that, if you don't want to UV your model in LW, you can do that in
ZB.especially valid if you paint your textures entirely l in ZB.

matt-ksp
02-14-2006, 02:51 PM
"... if you don't want to UV your model in LW, you can do that in
ZB.especially valid if you paint your textures entirely l in ZB."

i'd say only use the automated tiling option IF you do all your texturing in ZB, otherwise your seams will be in the wrong places, in fact, everything will be in the wrong place and will be nearly impossible to edit externaly. it does work pretty well though.

i haven't had any poblems with tripling obj's (but mabye thats cos i havnt used any really high detail models yet? - hmm).

ub52
02-14-2006, 03:23 PM
Steve Warner has an excellent tut done in flash for the whole process. Here is the link.

-ub52
http://www.stevewarner.com/html/zbrush.html

Nemoid
02-14-2006, 03:23 PM
Yeah of course this is valid when working entirely in ZB.

thinking a bit tho, you don't hae the real need to work in photoshop the traditional way.
u have z app link plug, that exports what's in prpject master as a flat image and you
can paint that one in photoshop.
Zapp link will transfer yor results in Proj Master in a flash.
this way, you get best of both worlds.

this workflow is a good alternative for the classic one.sure there are new unwrap tools
in apps like modo, unfold 3D... and a nrecent little plug for Lw too, but especially
for organics i find the process i explained rather satysfying.

point 7 : ZB returns to the first version of the.obj you imported, but obviously it adds to it its UV

then, in modeler you can fire up Zwave plug. open your .obj from there...
it adds the UV map from it to your previous LWO.

PixelInfected
02-17-2006, 04:54 PM
good work flow, until lw9 and Aps will be out, is to build from zbrush a bump map for fine dectail, like skin pores, and scar, for most of sculpting use displacement. it's a faster and optimized workflow for lw.

Lyr
02-17-2006, 05:21 PM
thinking a bit tho, you don't hae the real need to work in photoshop the traditional way.
u have z app link plug, that exports what's in prpject master as a flat image and you
can paint that one in photoshop.


Interestingly enough this used to be the way to texture in lightwave before NT added UV's. It was really easy to do and didn't require painting in a wierd distorted way to match the UV map. I liked it alot. I am really glad to have projection painting and the benefits of UV mapping so readily at hand.

Lyr
02-17-2006, 05:36 PM
I almost forgot, there is another useful little trick from the LW projection texturing days that is really useful in zbrush. Save a morph target of your tool in it's default state, isolate the region you are going to paint then use the deformation tool flatten to make the surface perfectly flat for projection master, when you pick your model back up just morph back to the original state.

Nemoid
02-18-2006, 12:32 PM
very interesting trick, Lyr ! :)

richcz3
02-19-2006, 01:43 AM
Not sure I understand the tripling of the geometry on export from Lightwave as an OBJ. Steve Warners tut works fine for me up and including the UV's in ZBrush.

Here is yet another real good way to get ZBrush models imported/exported back into Lightwave with maximum effect. ZBRush Central (http://206.145.80.239/zbc/showthread.php?t=32584&page=1&pp=15)LIGHTWAVE to ZBRush and BACK (http://206.145.80.239/zbc/showthread.php?t=32584&page=1&pp=15)


Of interest is his use of "AUV Tiles"over "GUV Tiles"for generating UV's.
- Use AUV Tiles rather than GUV for the tool's mapping. You may want to set ratio to 10 or 12 if your model from lightwave has wildly differing polygon sizes. GUV more often have overlapping uvs

claws_33
04-17-2006, 08:25 PM
everything that you guys have said has helped me alot. now my only problem is, how can i texture my model in zbrush using different maps? I think it would be easier to focus by only seeing so much at once, not to mention easier for my computer which isn't all that, nor a bag of potato chips. can i use maps i make in LW? or can i make new ones in ZB? thanks all^_^

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