ZBrush with OBJ files

[kablooie]

Hey all,
I'm a new zbrush user who's a bit stuck and was wondering if you could help me out? Basically I need to nail a process that would allow me to import a low-poly Lightwave car model as an obj and add resolution to the mesh in the areas I want while keeping the rest of the mesh low-poly. The problem is that for technical reasons the car has been modelled in parts: the doors, the wings, the bonnet etc. are all seperate (unwelded) parts. Therefore when I divide the mesh to add resolution, the car breaks up into strips of high res polys whose edges no longer touch - so the model is ruined :( Basically I want to add detail to the cars edges without losing the hard lines. The mask selection part of zbrush I find totally confusing as there seems to be no per-poly control of the mesh like usual 3d programs, it's all rather global. Is there something I'm missing as regards this low-level control that I need, or am I just using the wrong package?
Thanks in Advance,
Kab.

[Frenchy Pilou]

Maybe you must read the practical Guide (http://www.pixolator.com/zbc-bin/ultimatebb.cgi?ubb=get_topic&f=1&t=014968) for the new selections of the Zb2 :)
There are some edge loop and other facilities for select :)
Pilou

[aminuts]

edit:

hahaa i reread your message and I read it wrong first time around so my answer was useless.

Frenchy's suggestion is most practical. You could try playing with import settings as well.

[lovecrafty]

Kablooie,

What I think Frenchie is getting at is do not use the mesh divide button to subdivide your mesh, I did the same thing with an .obj file imported from poser and it did the same shrinkage thing you describe. With poser I could weld the thing together as an import option, but in your case that will not work unless you want to cut it apart again in the other application. Instead hide (not mask) all but the areas you want to add more geometry (using ctrl-shift drag) and hit the edge-loop button. So for the hood of the car (bonnet?) if only the hood is selected the edge loop will go around the edges of the hood only, and you can adjust the curvature/fit or whatever using the move command with a setting of 1. Then you can move a single point of the mesh to where you see fit. Repeat for any part of your car that needs refining. I hope this helps a bit!

[ElCheese]

Haven't tried this out myself, but I believe that if you use the "crisp edge" function around the border of your object within zbrush, it will stop the shrinkage(and keep your hard edges). Might be a bit of a pain to set up though. There's a section in the practical manual showing how to do this, but try a test first in case I'm wrong :D

[aurick]

The Crease function will prevent edges from shrinking when the mesh is divided, and won't add any geometry to the mesh either.