ZBrushCentral

Create Shell Issue

ZBrush Usage Questions
#1

Hello everyone,

I found some threads about create shell issues but not similar to what I’m experiencing at the moment.

I designed this ring in Rhinoceros. I had to hollow it out and it is a pain in the neck to do it in Rhino, so I exported as an OBJ into ZBrush to use the Create Shell command. To use it I knew that I need another piece which will be used to subtract it from the ring. So, I made that and exported it too the same way.

In Zbrush, I imported them into the same subtool. Dynameshed them with a resolution of 640. I set the cutter as a “sub” and merged down the positive ring subtool with the negative cutter subtool and got the thing on “1.jpg”. I want to have a wall thickness equal to the thickness that is visible at the edges inside the ring.

When I switch to “Dynamesh” section in Geometry section on the left, the default options was Blur 2, Project On, Resolution 640, Wall Thickness 4. I turned off the project and let the others be. When I hit the “Create Shell” button, I get the result on “2.jpg”. This was good except that it was too thin and it didn’t match the thickness that I have on the inside edges of the ring. So I increased the wall thickness to 11, hit “create shell” again and got the thing on “4.jpg”. As you can see, there are some problems there. I am not sure how to clear those super thin polygons (burrs) appearing inside the hollow.

If I increase the wall thickness value even more, I got the thing on “3.jpg”. Which, obviously, looks like a subtraction instead of a create shell operation.

So, guys, I need to get it done soon. Any ideas? I really love this feature, it is really handy for me. I need to fix this. Please feel free to ask any questions.

Thank you.3.jpg2.jpg1.jpg4.jpg

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#2

Holy crap, I’m essentially asking the same exact thing if you read my " getting artifacts after creating shell" post today!

I have the same problem but my issues are even on the outer surface. I’ll post a picture tomorrow. When you watch the official pixologic video on how to hollow models for 3d printing…they get a perfectly unaffected surface.

Oh, and I bet it has to do with the fact we imported the models and not made them from scratch in zbrush. Maybe we have to fix the topology first but wouldn’t dynameshing do that when we created shell?

#3

Hello Rick,

Haha, I guess same problem at the same time. Sorry about your problem, it sound funny because I never thought that it could cause an artifact on the outside of the model. I hope this thread will solve both problems.

Listen, what you said had caused a sparkle in me. I did what you said. After importing the OBJs, I immediately ZRemeshed them. Then converted to Dynamesh, merged them and did the create shell. The result is the same, unfortunately. Artifacts again. So we are one step closer to the solution. :slight_smile:

What else can cause this???

#4

Crap, I was just going to try dynameshing our imported models first, and then “create shell” to see if it would be a cleaner execution but it sounds like you already tried it.

I have no idea man. This forum, while I appreciate it very much, doesn’t seem to be frequented by enough people. I think our question is pretty simple.

Did you see that video I was talking about for “ask Zbrush” (how to hollow out models for 3d printing)? They get a PERFECTLY smooth model after hollowing.

I’m going to post pictures of my problem too but I’m not sure if it will help since you already posted similar pictures.

#5

Hi.

I found a promising video. This guy actually calls them “artifacts” like me after he first tried to create shell. This will help us.

Please watch the video and I will also try to experiment and I guess you and I will have to figure this out together.

#6

You are going to love me.

watch his other video for hollowing out a ring!

#7

Rick, man, you’ve got this resolved for me. I applied what’s been said in the video and the result is perfect. Thanks a lot. I hope that it worked for you too, didn’t it?

#8

I didn’t try yet but plan on trying tonight.

Which video helped you? Just the ring video or did you have to watch the longer video?

In other words, what did you learn will help us the most?

I also make jewelry but only has a hobby at the moment. I am self taught and use traditional tools like rolling mills, saws, and torches. But I like to create 3d models and have a buddy who prints them in castable resin which I then spin cast.

Do you make a lot of jewelry?

#9

Yeah, you should watch them both. I watched both. In the longer one you learn the process, he really is a good teacher. And in the second one he just does it in 3 minutes or so, I guess. Again, it solved it for me. Thanks again for sharing it.

I’m doing jewellery cad for 9 years now. I have a SolidScape T66BT2 machine, which I’m selling out at the moment. It is on eBay. (http://www.ebay.com/itm/152716072973?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649) Anyways, I started with JewelCAD then moved to Matrix, then to ZBrush. I’m dreaming to do everything in ZBrush one day. So, I designed models and have them printed. I hardly did any manual work after the pieces are cast but I know the process. Still, I think handwork is priceless and will always remain. You can check some of my work on instagram, “erdemokcuoglujewellery”.

I think though, you would open up a world of endless possibilities of creating new thing with CAD. Plus you have the ability to finish the products. This would make you a one man factory, which would be awesome. :slight_smile: