ZBrushCentral

Retopology Issue.

ZBrush Usage Questions
#1

Retopology Issue.
Hey guys I’m using a character I madel for a small personal project and I am in the process of retopologising the mesh ready for animation. I recently saved the file and came back to it only to find that the retopology tools were not working properly. For some reason any topology I create now is ‘invisible’ making it completely impossible to use. The rest of the mesh from the save seems to be intact but I just can’t finish the mesh. It is hard to explain so here is an image to help highlight the issue.

Mesh prob.jpg
Mesh prob.jpg1213×717 91.3 KB

Just wondering if anyone knows why this might be happening. Thanks a lot

#2

it looks like somehow the topology moved inside the mesh you’re working on.

try turning on solo and seeing if you can see the points now… at least to reposition them to outside the mesh and/or delete them

if that doesnt work the something else going on and it may be a start all over again moment which always sucks

some quick suggestions to avoid frustration with the retopo tools…

1 only save after turning off edit topology… wierd things happen when you dont like occasional loss of symetry and points flying off to nowhere… occasionally you’ll also get a complete file corruption and the tool wont open at all anymore which sucks bigtime.

2 if you are rebuilding topo over a surface build first your big faces to conform to the surface as much as possible… then switch solo mode on to turn off the mesh surface you’re drawing on and use the wireframe mode to split faces into smaller parts. control-shift to use clipping mask and hide sections as necessary to focus on smaller parts of topology… you may wind up with some points being under the surface of where they would’ve been if you hadnt turned solo on, but you’ll save time in trying to hunt down mid points and quarter points along edges because you’ll be able to much much more clearly see where all of your points are

3 turn off edit topology and save iterations of your file every 20 or so points you lay down… get in the habit early. nothing sucks more then getting into a deep retopology on something… being extremely happy with the progress… laying down a few hundred points… then zbrush craps out and you are literally all the way back to square one. when i work with the retopo tools which seems to be much more often now, the naming structure i like to use looks like this :

filename1A1.ztl

the first one is the major version of the tool … every subdivide gets a +1 … the A is every big change in either topology or detailing but no change in division level… the second 1 is smaller detail changes that i may want to backtrack on or iteration saves while working on retopo.

an example is if i were working on a face. i keep all iterations in a single folder per project… starting at div 1 save as 1a1… add my eyes and mouth basic forms… 1b1… add nose 1c1 … retopo pass 1c2…1c3…1c4 at each 20 points… divide… 2a1… add more detail to mouth 2b1…

etc…etc…etc… sounds like a pain in the ass but if you’ve ever had a file eaten itself you’ll wish you could go back a few steps and try again without losing a drastic amount of work… you also can just delete previous passes when you’ve gotten far enough to be satisfied that you wont need to make drastic backtracking again so its not like they’ll take up a lot of hard drive space… not until you get to the 5a1’s and such :wink: … but you may find that you dont want to go and delete anything because if you’re ever working on something similar down the line you can pull up an old iteration of a previous work and you now have a large range of starting points for the new project. always a good thing to have quickly identifiable initial meshs to speed up your workflow

#3

Hey there,

First, of all I’d like to just say thanks for taking the time to post such a detailed response. I will definitely keep these things in mind for my next project.

However, I have retopologised the entire mesh but the hand and as I am fairly new to this it’s not a fast process. I have seen people ‘borrow’ the topology from their zsphere mesh before (for example if some of the geometry is actually usable from what the zsperes gave them they can use a section of that mesh as a basis for the retopology). Surely there is a way to do this for my situation. I.e. use the topology of what i have done so far and over lay that over my high polly?

I hope you get the point I’m trying to make, I might not have explained it too well.

Thanks again

#4

I don’t know what’s going wrong but you can try this:

  1. Set the Tool>Adaptive Skin>Density slider to 1.
  2. Press Tool>Adaptive Skin>Make Adaptive Skin.
  3. Select the ZSphere tool (just the starting zsphere, you are going to start new topology).
  4. Press Tool>Rigging>Select Mesh and select the mesh that you are creating new topology for.
  5. Press Tool>Topology>Select Topo and select the mesh created at (2). It will be called something like Skin_MyModelName.
  6. Press Tool>Topology>Edit Topology.

You should now be able to add new points to your existing topology.

#5

another thing to note… if you’ve already started retopo-ing part of your mesh… but another part you like how the topo was originally and wanted to just take that topo back into the retopo you’ve done… you can do this. lets take your mesh and the hands as an example

in your original mesh clone a copy of the subtool… isolate the hands and make them into a seperate polygroup and then group split them off. make sure you have this mesh at the lowest subdiv level you wish to work with and delete the upper levels.

in the retopo you’ve done already, get your topo up until about an inch up from the edge of the hand you saved seperately. … delete any extraneous points that you may have created on the hand and export this to an adaptive skin with only 1 subd level.

make sure both pieces at this point are relatively similar in subdiv level, and that their combined points have not exceeded 10-15K. Idealy you should only be at a few thousand at this point anyway. Append the hand subtool with the original topo into the just created adaptive skin… merge these both down to one subtool that again needs to be under 10-15k polys.

save this as a seperate ztl for backup… load up a zsphere (not append… just straight load) … shrink the zsphere down and move it off to a corner. in topology select topo the mesh you just saved with the subtools merged. edit topology.

now you can play connect the dots between your retopoed mesh and the hands.

This is really the only way to mix topology between something your in the middle of retopo-ing and something that is already complete… sometimes you need to retopo things bad but there’s parts that you like them as is and dont want to try to recreate… i find this works for me to connect the 2. if you plan out your retopo well enough to line up with similar points in the old topo you can usually combine the two without any visible artifacts of the combination… if you leave just enough empty space between them you can easily see where to make the connections.

hope this helps some.

edit… and just to note… i didn’t list the rigging step in this that most people like using… the only reason i did not is because when combining two meshes its easiest to only look at the wireframe this way you can safely make connections without crossing wires so to speak. when you rig you’re kinda forced to work only on the surface and see only on the surface which is fine for your normal everyday retopo but doesnt work great when filling/creating holes, and editting new geometries from existing meshes.

#6

Could it be something as simple as a mask got inadvertently applied to the model and needs to be cleared?

#7

it happens… check the masking sections if hitting clear does anything… but it seems like the directional lines from the sphere it’s connecting to are pointing towards something being under the surface… have you checked if its visible with solo turned on yet?