ZBrushCentral

high frequency details on 1gb ram?

ZBrush Usage Questions
#1

hallous, first post here.

i’m having trouble going into fine details on a (very wrinkled) head. i imported it from max and added all detail i wanted from level 1 (1.3k polys) to 6 (1.3m polys). when i go into level 7 the mesh goes to 5.2million polys . it get’s slugish but it’s still workable. problem is if i save i can’t load it anymore (it states insuficient memory and crashes).

searching zbrush central i’ve found two possible solutions:

. breaking up the model, post #6 from aurick;
. using bumpviewermaterial and have the details on a bump instead of the mesh.

none of them is ideal. in the first one, the level 6 details seems to get lost after i do the “delete hidden” step (even with Subdivision Smooth off), so i’d have to work on everything, even the low frequency details (the hard ones) with it divided (and not divide it later). and using the bumpviewermaterial, i loose the beloved smooth tool.

i’m considering:

. adding another 1gb of ram;
. throw away all current work (it’s not much anyways…) going back to base level mesh and add lot’s of loops where i want more detail and try to work out everything in level 6 (which, hopefully, may not get much more than 2m polys).

any thoughts on that? is 5million polys workable with 2gb of ram? how do everyone do fine details??

any other solution?

cheers!

#2

I ran into a similar problem. The way I solved it was this.

Each time you sub divide it quadruples your polygon count. So what you can do is go down to level one of your subdivision levels with part of your mesh hidden. Usually hide the parts that are most dense on your lowest level. Then hit Divide this will subdivide the rest of your model a little bit more and you wont loose any info on your other subdivision levels when you go back up. And also you will find that one of your levels will be between your previous 1.3m poly level and your 5m poly level. So then just delete the highest level and work on the one below that. At that new level you should then have enough polys to get the kind of detail you want and you will still be able to load your model.
Don’t forget to also save your model at the lowest sub d level for better file size and load times

#3

you need to save the model on subd level 1…as a .ztl …don’t worry all your levels will still be there but this way you save on disk space as well as being able to save and reload it later.

think about it…if you load it from a saved level 1…it takes a second or two to go up in levels right? higher the level the longer it takes to configure…and that’s just going up one level at a time…now imagine the brain fart going on if you load a say…level 7 mesh that’s in the millions of poly’s…not only does it need to figure out that level but all the levels down to one…which means it needs mucho memory and virtual memory to get there. Even with 2gigs in your machine…saving such a high rez ztl is gonna give ya fits and probably give the same error.

#4

This is also one of the exact reasons why the Performance Tips (found in the General section of ZBC’s FAQ) stress that you should NEVER set the MaxPolysPerMesh slider to more than double the default value.

With 1 GB of RAM you just don’t have enough to go over about 3 or maybe 4 GB reliably. 7 GB is certainly out of the question.

#5

thanks for all the answers!

i ended up starting over with a new base mesh. i come from game dev and i’m used to add vertexes only where there’s volume needed, so my head had some parts more denses than others (like nose, mouth and eye). that left the rest of the head with few loops/edges that, subdiveded till level 6, did not had enough to add fine details (like in the cheek), although other areas had. adding loops in the base level mesh gave me a 2.5million poly mesh in level 6, with enough density to add fine details.

so that’s a new thing i discovered: if you don’t have the base mesh homogeneously low, you should add loops where you want to add details later.

–E--, i could have used your solution, but i was planning to use displacement mapping later, so changing the base level mesh like that wasn’t really a good option.

amintus: your solution worked also, saving the tool in level 1 really worked out (and is going to save me tons of hd space :slight_smile: ). but in the end, working with a 2.5million poly mesh was better and faster than one with 5m. :stuck_out_tongue:

thanks again!!

#6

hey there,
i am having a similar problem, only when i get to the higher level of poly’s (in the millions) and up to level 7, if i go back down to level one, then back up to level 6 or 7, the mesh goes totaly messy, and i lose all the detail…or the file crashes, and ive even had now, where the file tries to save, and then when i try opoen it, there’s nothing there?
im also on 1 gig of ram, and finding this to nearly be impossible to get decent quality out of my models.

#7

baker…are using a polymesh or imported model or are you using a zsphere model in preview mode?

couple things to remember or check…

on an imported model be absolutely sure all your verts are welded.

when select hiding for detailing be sure to turn double sided on and rotate rotate rotate that model around so that you don’t miss a poly by accident…specially at higher rez’s because you could be moving it without knowing it and basically messing up the model’s structure and when you try to do things later zbrush is gonna have a hard time trying to figure out what to do with that stray.

if you used masking be absolutely sure it’s cleared before subdividing unless it’s your intention to only subdivide a part of the model. sometimes by accident some little part gets masked when select hiding as well…specially if you are trying to do it fast…ctrl-drag=mask ctrl-shift drag=select/hide…you can see how it might happen by accident. if you move things around or subd with it on strays can happen that way as well.

ummm that’s all i can think of at the moment.

#8

thanks aminuts-

im not masking anything at the moment with the particular model its happening too, but the origonal model, it was happening!
im not sure what you meant by stray? i did however notice, that when i sub-divided it lower, there was a strange poly coming out of no where…is that what you are talking about? as soon as i saw that, is when the problem started happening.

im using an imported mesh for all these models too, and hopw to get the detail for displacment, but as i stated before, it crashes before i get there, and that can only be on level 6…its wierd, cause i dont change the level, but i do all the detailing i can in 6, but then all of a uddon it crashes? and i havnt even hanged the level up or anything?