Lag in Zbrush

[MooseCommander]

I've recently started using Photoscan in my game art pipeline.  The results are fantastic.

My only issue is that importing the .objs generated from Agisoft to Zbrush cause immense slowdown in the application.  Zbrush should be capable of working with meshes of up to 8,000,000 or so verts before running into serious issues.  I'm able to import .objs from Maya or 3ds Max of this density without problems.

For some reason, files generated by Agisoft cause Zbrush to run extremely slow and often crash the application.

Any idea why this is happening?  Anything I can do in Agisoft to export a cleaner mesh at the same density?  Anything I should be doing different inside Zbrush?

Thanks! 

[chrisd]

ZBrush is a 32-bit application. It cannot use more than 4Gb of ram. I've heard Pixologic will release a 64-bit beta version with  4R7, but that is still pending.

[nadar]

try maybe to simplify the mesh. Meshlab offers good tools for this

[admir]

Your mesh from PS comes with atlas UV and vertex coloring. If you plan doing any serious editing in ZB you should retopo model, apply subdivisions and project from original scan. This will minimize lag in ZB.
Admir

[igor73]

I found that Zbrush has a limit of around  20 million polygons and often it crashes if you are near this poly count.   Usually i decimate in photoscan to a  more managable 10 ml ploys before importing to Zbrush.  I only use this high poly count for large area scans of say 500 images.  On objects usually 2 million polygons is more than enough i think.  Decimation master in Zbrush is great as well.

[admir]

Editing 8 mil polygons in single mesh without subdivision levels is useless in Zbrush.

[igor73]

Quite unnecessary to go that high as well.  Decimation master can retain almost all the details on scan data.  From 10 mil decimated to 1mil and i barley see a difference.  When is started editing scan data i tried to stay as high as i could on ply count.  Now i don´t bother with it.