Hi, I started a project on my imac at home, sculpted a model, used displacement and normal maps for renders in Maya, everything was working the way it was supposed to. At a certain point my scene got to be more than my computer could handle (imac, osx Lion 2.8 ghz dual-core, 4 gigs ram), so I brought it in to work where I have some better resources. (At work I have a PC running Windows 7 64 bit, dual 3.0 ghz quad-core, 12 gigs of ram.) I also use 3d studio max at work, so there was a little conversion, nothing big. Anyway, I had created all my maps on my computer at home, they worked fine, looked great. When I got to work I realized I’d have to convert my maps, but for some reason the 8192x8192 32 bit displacements made on a mac won’t open in photoshop in windows. I figured there was some kind of byte order problem happening, so I exported the exact same maps in my PC version of zbrush. Same exact settings, except I had 3 channels turned on cause max doesn’t like 1 channel. The maps that exported looked completely different, the blacks are all crushed, so I lose a ton of detail in the recesses of my model, and the overall black and white curve is completely different as well, on pc the levels highest point is in the shadow areas, and as i said, they are completely crushed to 100% black in areas that should have varying levels of gray. On a mac, they are highest in the mid tones of the curve, with no clipping of the light and darks, they way they are supposed to be. Has anyone else had this problem? I was going to upload some images, but I still can’t get the right looking maps to open in photoshop, which is another baffling issue altogether. The main issue here, is why my maps look so wrong when exported from zbrush for pc.
ok, I was just bein stoopid ah guess. I don’t usually post until I have exhausted all solutions, but I have just been a bit frustrated with a few things lately. Anyway. I had my mid value in the export settings set to 0 rather than .5, which is a bit embarrassing, but it does lead to my next question, is there some linear workflow reason that the tool hint says “for best results with 32 bit maps, use a value of 0”? So far, any map I have made with the value at 0 severely clips blacks, leading to positive displacement, with flat smooth areas with no value at all. Is this just my ignorance showing here? or is there a good reason for this?
32bit maps give positive and negative displacement relative to the scale of the object using real-world scale. See here: http://www.zbrushcentral.com/showthread.php?25542-Rendering-Zbrush-Displacement-Maps-in-Maya&p=862303&viewfull=1#post862303
You shouldn’t edit a 32 bit map after creation, and looking at it in Photoshop won’t give you an accurate guide as to how it will displace your model.
Ok, thanks for the response! I don’t usually edit my disp maps in photoshop, I was just trying to troubleshoot some very basic stuff and thought it might help to see how photoshop interpreted the situation. Like I said, in maya, I had no problems at all, and I never seem to have issues in the zBrush maya workflow. It’s pretty straightforward. In max, however, identical maps were used, and it gives me different results whether I use height map displacement, extrusion map, or a displace modifier. Max can be a pain like that. The one thing it was consistently doing was clipping the darkest areas, and i guess that seemed like it was confirmed by checking the levels in photoshop, where it seemed to do the same thing. I also thought, because one problematic map was from a fairly large ground plane, that it didn’t have enough levels of gray to get all the detail in the lowest part of the maps, which I know is probably silly, but max will clip displacement that goes outside its maximum displacement range. Anyway, the problem goes on. I love working with Max and with maya, but maya just seems to be so much less picky sometimes. Thanks a lot for the info, Marcus.
It sounds as though it is Max that is causing the issue. 32 bit maps have about 4 billion levels of gray (compared to 65,535 for 16bit) so that shouldn’t be a problem. 
I have had the exact same problems opening 8K maps in photoshop since upgrading to 4R3. I use Nuke to convert the tiff’s exported from Zbrush to tiled .exr’s for much better performance in Maya/Vray. After upgrading to 4R3 the multimap exporter is basically useless for generating 32 bit maps both 4K or 8K. If I try to render out 8K or 4K maps with the multi map exporter I can no longer read those tiff’s in Nuke or Photoshop. In Nuke I get an error saying it encountered a problem at line 4095 expecting X amount of bytes and got zero. Same with an 8K except it’s at line 8191. What this is telling me is that ZBrush is no longer writing out every line of pixels in the map and leaving the last row blank. The only way I have of fixing this is to open the 4K map in Photoshop first, which doesn’t give me the same error as Nuke, and then save over the file thus writing out the last line of pixels. Then I can open it in Nuke. Most fo the models I work with have 4 to 10 or more UV tiles and thus the need for the multi map exporter, this is becoming an extra step that is getting to be a royal pain, especially when I never had this issue in 4R2. The “opening in Photoshop” trick I mention doesn’t even work for 8K maps as those just plain don’t open at all with Photoshop giving me the error “Unexpected end of document” again letting me know that ZBrush is generating incomplete files with the last line of pixels missing. 16 bit maps do seem to work but we use 32 bit in our pipeline and that’s not going to change, nor should it have to since this was working fine before.
Is there going to be an update for this issue? In the meantime the only recourse we may have is to roll back our Zbrush installs. Which we don’t want to do. Right now were basically limited to 4K 32bit maps that I can open in photoshop, save back out, then open in nuke and then write back out. We really need to have 8k open to us for a lot of extreme detail close up shots. We can’t be the only folks having this problem, and all of our 16 users are having the same issue, does anyone else know what’s going on here?
trancetechkid,
I’ve not heard of this issue before. The 4R3 MME code that handles 32bit disp map export is the same as for 4R2 and actually simply uses the ZBrush ‘Tool>Displacement Map>Create and Export Map’ button. Please test exporting a map directly using this button and also make sure that the issue is not related to a particular model.
If you continue to have problems then you should open a ticket at the Support Center.
Thanks,