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Imported Mesh Exploding.THE FIXX.

ZBrush Usage Questions
#61

I have not used the FBX method for a long time. Since I’m using Max2008 I had no more difficulties with exploding meshes.
Of course I don’t know whether this is due to bug fixes in Max2008 or because of the meshes I worked with.

But I remember that there was nothing more to the FBX workflow than what garycrump described and I complemented.

You say that the number of polys stays the same but the number of vertices changes. That sounds like unconnected polys. I don’t know where this might happen in your workflow.

I attach my OBJ Import/Export settings that I use to exchange between ZBrush 3.1 and Max2008.

-Andrea

Attachments

zbrushIE.jpg

#62

Hi guys
When I use FBX converter to go from obj to fbx it works for a very low rez obj but as soon as I try an obj that is exported from zbrush after it was subdivided the FBX converter does some very nasty stuff.

First it starts and then it just takes over the cpu capacity to the point where I can do nothing else and it just does not seem to want to finish the job.
Is this problem peculiar to my system or is it a problem others have encountered?
Any help is appreciated.

PS I have found that if I import an OBJ into ZBRUSH 2 with merge on and save out as a tool and then open this tool in ZBRUSH 3.1 - then when I subdivide I do NOT have an Explosion of the mesh.
Now I have only tested this a couple of times and maybe I was just very lucky but let me know if this helps anybody.

#63

… here come the other settings.

-Andrea

Attachments

zbrushIE2.jpg

max2008Export.gif

max2008Import.gif

#64

Use max importer / exporter
Max9 and ZB interaction with the model document is not ideal.
I also tested max sp2, model still explode.
Some users (max 8) said that there was no such problem.
Max users also said 2008 had no such problems.
But I testing, import and export can sometimes feel normal, but it is absolute.

Use Guruware importer / exporter
I Feel the question(max) is very strange, and some models use Guruware importer / exporter plug-in the normal iimport and export (Subdivision not raise the explosion), but not on some models, with whether there is a triangular model is not directly related, because There are many triangular face in the models , but as normal, but some models (no triangular) is still explosion.

Sometimes the use of the Guruware max plug-in model will change the face amounts, but do not change the Vertices, on the Tool>import subpallete,you can adjustment the Tri2Quad slider, set to 90, can be successfully imported, but Some models do not trip.

I use the max 9 own import and export obj fuction , although not to change the number of points and face, but I import obj will no doubt be a blast in ZB .

Use FBX
1.zb obj - FBX converter - FBX
2.max FBX-FBX converter - obj
3.obj - zb

But FBX format export can be avoided this problem, from entering FBX max, the FBX export settings :

“Misc” and “Coordinate” regional options remain unchanged, "Export Options " Regional only check “Geometry” option. Use the free FBX converter to convert obj file, do not check the "Force Triangulation of exported meshes “and” Compute link and shape "option.

Fbx document will generate a lot of points, but no redundant face, it is impossible at this time directly into a success, users can zb Mrg inside activation switch, setting Weld slider to 0.01 , and then import it, the software will pop up the dialog box, click Ok these extra points were merged. sometimes This import will have a scalable model (smaller). We can click on
Tool> Deformation> Unify button, and the proportion of the model resume. Restored, upgrade to the sublevel model, no Explosion.

With third-party applications to output Obj
If not use max to unwrap UV, and will save ZB max between the import and export, to the dismantling ZB and UV Interactive documentation procedures, and then the final document will be read only to the max.

#65

I don’t suppose FBX could possible work with a Rhino 4.0 to Zbrush workflow could it? Rhino can export OBJ/ DXF/ 3DS.

I guess if I am starting from a trimmed Rhino NURBS model this would not work, Maybe stl scanned data?

#66

Hi Guys I Have The Same Problem As Some Of You The Picttures Say It All

#67

Actually this works only if you import low cage subdivide and import highres (which ends up destroying uvs if your higres had uvs) one time.

If you import the lowres cage(the very same one from your modelling software) one more time to low res cage after you constructed your sub leves, it EXPLODES. At least that is the case for me (using Modo) So what I am thinking is that it is not even the .obj format that is causing this. This has to be ZBRUSH. I am little pissed about this because I have wasted %20 of (which accounts for over straight 20 hours) of my current project time while I was dealing with these explosion issues. And I am sure I will waste another 20 hours to deal this issue since I am not done with the project. I am actually little more than pissed. Because everyone`s time is important, not just Zbrush developer`s time. Everyone is throwing the ball to eachother when it comes to this particular issue. Modo saysthat it is ZBrush , ZBrush says it is .obj blah blah. Take the responsibility and fix the damn thing please.
#68

kursadk is so wright – i mean all this importing and exporting really gets on ones nurves it would be great if some one finally finds a solution that works with max maya or what ever you are working besides z-br .when the mwsh explodes i feel like destroing the damn PC and all the hard work seems gone with the wind .So if someone can develop a way that does not include all this play of dots we will all appreciate it i think and we will be more productive artists than we are now . :evil:small_orange_diamond:evil:small_orange_diamond:evil:small_orange_diamond:evil:small_orange_diamond:evil:small_orange_diamond:evil:small_orange_diamond:evil:small_orange_diamond:evil:small_orange_diamond:evil:small_orange_diamond:evil:small_orange_diamond:evil:

#69

I also had the exploding mesh problem when I changed the UV’s in an external package. (cinema 4d 10.5)

What worked for me was NOT to use the standard obj exporter in cinema but use the riptide plug-in. No more exploding meshes for me.
Seems like the basic obj exporter in cinema changes “something”

also, when I rename an imported obj in cinema and export it and then import in zbrush… zbrush crashes… So basicly what I do is import it… don;t touch the mesh, only modify or add the uv mapping. then export it out again as obj… both with the riptide plug-in.

Peter

#70

i have fixed it :D:D:D:D

#71

Hi!

i had the same problem over and over again. Messed up meshes in the higher subdivs after reimport a lowpoly version with new uvw coordinates.

i think i got the solution:

i presume you export the lowpoly version out of zbrush into your favourit 3d app (in my case: 3dsmax) and then fix your uvws - export it back as obj and reimport into zbrush into the highpoly version.

the fractal mesh problems in zbrush are the result of small changes in the topology that happens during the exchange between zbrush - 3d app - zbrush.

Solution for 3dsmax (should be similiar in other 3d apps):

-reset max

Import
during the obj import dialog in max you have to choose the following settings:

  • Single
    checked - rotate model
    checked - Texture coordinates
    checked - Normals
    UNCHECKED - unify <— ! this causes the problems! it modifies your topology!
    checked - Obj smooth groups
    Vertex scale 1,0
    unchecked - Center Pivot

the “use materials” doesnt matter

UVW fixing / Creation
-now convert the model into “editable poly”
-use the unwrap UVW modifier to fix your uvws or create new one

!dont change ANYthing in the topology of your model!

Export
then you can “export selected” your model with following setting:

group by: object
(materials are ignored)
checked - rotate model
Faces: Polygons
checked - Texture coordinates
checked - Normals
checked - Smooth groups
Vertex scale 1,0

of Digits: 6

UNCHECKED - Compress numbers <-- this would change
UNCHECKED - Relative vertex numbers <-- your topology! ->BAD!

Back in ZBrush

-load your zbrushed model with all the details.
-go to subdivision step 1
-import the lowpoly obj with the new UVWs.
-you can then go to the higher subdivs again. and everything should be fine.

If you make the smallest change in your model. during import or export, it wont work!! just try every combination in the import and export settings and make sure your obj is just changing the uvw coordinates!

this worked for me…

Greetz

PS: i have another problem with multiple UV Sets and the ZMapper. if i try to create a normal map for one UV Group, the zmapper just creates randompixels and displays a messed up mesh. Any suggestions? except the method with groupSplitt. i dont want to use subtools.

#72

The funny thing is that this happens if you try to upres after you import, not when you downres the mesh.( I realized this after needing to fix one of the mid res version in my modelling app)

Pixhellman, changing topology has nothing to do with it. I have cases where I took my zbrush model to modelling app and making drastic proportional changes and bringing back without having any problem. This is a kind of problem does show up when you need a real fix or real uv for your model, and it does not show up when you try to explode a mesh for fun.

One other issue is pixel pixol ratio sometimes is not that great thus you cannot zoom to your model enough, so you need to take the model to another application. And most of the time zbrush explodes these meshes. I had cases where simple uving explodes the mesh inside Zbrush.

I think that this is somehting introduced during 3.1 update. AND THIS NEEDS TO BE FIXED ASAP.

Btw if you have found a fix or work around , please do not share or post here. Because as long as there is a so called work around Pixologic wont solve the real problem.

#73

Here is a dramatic case,

I am working on a creature head at the moment and I have needed some fixes outside ZBrush. I exported the model from ZBrush, imported in to Modo. And I did some test changes and test uving to see if ZBrush would explode this mesh before I spend my real time for real work in Modo. I exported from Modo, it is all good Zbrush imports fine, no explosions and I was happy. Great story is not it?

Well since Zbrush was not exploding the mesh I thought I should work on the fix and uving. I imported the very same model into Modo. I did proportional fixes and some other changes that was similar to ones in the test. I exported the model when I was done. Well you think that it should not explode right? It actually exploded and wasted just my 2 hours. Is not it great story?

#74

The FBX solution doesnt work for me and I’m not going to be able to import high rez models into max …
When are we going to have a decent workflow between Max and Zbrush ? :frowning:

#75

" If you do these steps the mesh will not explode because you are using a virgin model directly from the application. note:"

Actually I do not agree with this particular finding. Virginification of high or low model has nothing to do with this. You wont get explosion not because you have a virgin mary model, but because most likely from high res to low res(downresing) wont explode any model. Explosion most likely happens during up resing your model. So in your case since you cannot go higher than the highest resolution you wont get explosion. You were just lucky to find out that this method works, but your final finding is not quite the only explanation to this issue.

Try actually exporting 3 versions from zbrush, lowest, medium and the highest(a model that gives you explosion headache) .Then import into Max and export them out of Max and do the same method you just explained. But this time once you have established your subd levels goto medium res and import your medium max exported version. Most likely you will get exploding polygons.

#76

I tried the “virgin model” technique.

I open an OBJ with properly unwrapped uv’s . . . when I import the highres (finished sculpt) model over my subdivided unwrapped model it will not explode into a porcupine mess . . . .

however it still has the crummy old uv’s that are no good to me.
I even applied a texture . . . that worked on the properly unwrapped piece and dissapeared when I threw the highres mesh over it.

Am I missing a step?

Is it stupid to try and uv a piece after you sculpt it?
Is everyone else just unwrapping before they put all their detail into the meshes?

#77

I have the same problem except I’m not even importing into a 3rd party application. I simply export my low res, export my high res then:

Import low res to new
Sub Div low res to same as high res
Import high res

When I adjust to the lower sub div levels it looks fine and then as I go back up it explodes.

Again, this is when I’m simply exporting directly from ZBrush and importing straight back into ZBrush.

#78

Kosher

Thank you for confirming my points!! They need to fix this …crap.

All these solutions in Zbrush forums regarding this problem are all accidental . None of them are real solution. Zbrush has mental problems when it comes to importing into existing geometry. It can not even handle its own geometry-image formats properly(I had very same issue you have in the past as well) . This is very much overlooked issue and I would say that ignorance plays some part in this particular problem. People are b…thing about this for quite sometime and I have not seen anyone from Pixologic to comment on this problem. Only god knows why they have choosen to do so.

#79

I’ve noticed something that might be related. In the original mesh, I hide a certain polygroup and then as I slide down to subdiv level one, part of the polygroup becomes unhidden.

Could this be some indication that the UVs from the very lowest level are different than the levels above it? I have also tried just exporting from subdiv level 2, where the issue mentioned above does not occur but I still have the exploding mesh dilemma…

Yes, this is no fun.

Could it also have something to do with the detail painted in layers at the higher sub div level?

#80

Ah ha! Got it! It had something to do with the fact hat I was hiding polygroups and exporting.

I was unable to use the delete hidden button until marcus responded to my recent post about being unable to get rid of the HD layers, where he says to use the SubTool Master. I duplicated my tool using subtool master and the HD layers vanished.

I then opened up the new ZTool I created from the SubTool Master, went down to my lowest subd level, hid the polygroups that I didn’t want exported, then used the Geometry>Delete Hidden function (this was the key). Before I was just exporting without deleting hidden.

Now all is well and I was even able to keep my high details that were in layers.

Good luck!