Z-Brush Beginner Question - Importing without Triangulation and just Quads?

Hello everyone, I am new to Zbrush as I just picked the trial version up today. I am wanting to import a model that I created from Blender as an FBX and into ZBrush so I can sculpt the model. However, whenever I land the model up on the scene, I get weird missing pieces in the model which I can only suspect are the N-Gons. This would lead me to having to triangulate the model, but here is what the model looks like when its subdivided up to level 3/4:


I get these weird creases around the skin like you can see in the image above. Is there any way to fix this besides having to manually smooth everything out? Because I think this is only caused by the triangulation of the model, even the wireframe looks a little strange to me:



I have also tried importing it as an OBJ but I get even more missing pieces of the model... Is there a way to upload models within Zbrush without having to remove the N-Gons, kinda like Mudbox does? Or a more efficient method to import models altogether? Thanks for your time!

Replies

  • kanga
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    kanga polycounter
    I dont think zB will quadify your mesh on import. You can however do that operation yourself by making a copy (duplicate) subtool and then running zremesher on it. There are a number of sliders associated with the tool and if you check it out on youtube there are also a couple of different algorithms you can try out to see which one gives you the best result. You can also use the topological brush to draw lines on the duplicate before remeshing to define the edge flow, like eye and mouth loops and so on. Depending on what range of resolution you need to work with you can use the reconstruct subdivide to gain a few levels of division, You can also remesh your model to a low sub level and then divide it up, then take the lowest level and project the details from the original onto the new copy doing that for each level. Google is your friend.

    As far as importing your mesh, zB has a plugin called GoZ. I work with Blender too and the Blender community has made a Blender friendly version called GoB.  This addon lets you jump between B and zB (and back or in any order) with the click of a button. One thing to note though: Blender and zB have a fairly one on one relationship to scale but if your mesh is too large in zB your brush size rage will be limited. If that is the case then you can unify the model and it will be at the right size and position in zB for all your detailing needs. Another thing is that GoB  doesnt respect the Blender 'Z' axis setting and uses the position of the Blender origin point. Just something to be aware of while shuttling between the two apps.

    Have fun!
  • ChristheLancer97
    Thanks, I'll have a deeper look at Z-Remesher now :) I just thought there would be an easier way across this since Mudbox allows N-Gons and all without ripping those pieces off the model and the overall import process isn't as daunting as this. But I guess I should expect that going into a new software. Appreciate the informative reply.
  • kanga
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    kanga polycounter
    Oh yeah you dont have to use GoB, its just there if you need it. Obj and I think FBX works just fine.
  • cryrid
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    cryrid greentooth
    I get weird missing pieces in the model which I can only suspect are the N-Gons. This would lead me to having to triangulate the model

    Couldn't you just select the n-gons in Blender and manually fix just those specific faces prior to exporting, rather than triangulating the entire model? It might take a few minutes, but it would be worth learning how to do so that you don't have to throw out existing topology every time you want to pass a model around. 

    As far as Zbrush goes you can try using Tool: Geometry: MergeTris (under Modify Topology) to convert tris to quads where possible, though the results may not be as predictable as simply fixing the problem areas in Blender to begin with. 
  • ChristheLancer97
    Yeah I was thinking of doing for sure, but preserving that action as a last resort. I just thought I was missing something in regards to basic import settings, and I would have thought Zbrush could accept NGons through some intial import setting instead of completely deleting those faces, which I find slightly bizarre. But yeah, fixing the ngons in Blender would probably be the best initiative at the moment. Thanks everyone!!
  • cryrid
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    cryrid greentooth
    NGons are not supported, but they're not going to be deleted on import. If you import a mesh that has nonstandard polygons (more than 4 sides) zbrush will pop up a message asking if you want to split those polygons into sets of symmetrical triangles or a combination of quads and triangles. Whichever action you choose will triangulate those faces (and only those faces) so that the model remains water tight and suitable for zbrush. 



    Missing faces on import could be indicative of another topology problem, or its possible they're not actually missing (at least in older versions, zbrush used to have trouble rendering really low poly objects, so sometimes you had to subdivide once in order to check if a hole was truly present or if it was just a display issue).
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