Monday, February 20, 2017

ZBrush Portrait Sculpt Produced on 3D Printers

I finished a digital portrait sculpture and decided to realize it with 3D printing. I produced several reliefs prints and one full 3D print. This images shows three separate prints in a Walnut frame, 22" x 12" x 1.5".

Here's the full 3D print:

Sculpting Process

Here are some pictures of the digital sculpting process. I'm using a Windows laptop with ZBrush software. I can move around the model freely on a mobile stand.

I currently use a Wacom Intuos tablet (after using a Wacom Cintiq for years). I prefer this - it's cooler on the hand and much more of a relaxed position for my arm. And I can go for several hours without plugging in. Plus my hand is on the keyboard for shortcuts and Shift/Ctrl/Alt key combos which are essential in ZBrush.

Preparation for Fabrication

Here's the finished ZBrush model ready to prepare for routing and printing. At this point the hair, eyes, and face/shoulders are all separate objects. Doing that makes it much easier to sculpt. But they need to be one mesh to mill. The polygon count in ZBrush is 4.3 million faces. The polygon count needs to be reduced - a lot. Both DecimationMaster and ZRemesher were crashing in ZBrush. Very unusual. So I did it in Rhino using the ReduceMesh command. This is actually not nearly as good. But it was adequate.

Here's a comparison 4,300,000 faces on the left versus 360,000 on the right:

I had to fix a few really tiny naked edges and two non-manifold edges. This is fairly easy using Rhino's mesh tools (mainly DeleteFace and PatchSingleFace). I have to say - having a 3D Connexion mouse (I have the cheapest one) makes viewing and understand what to eliminate much easier. That's because you can twist the viewport so much more readily to see what's happening. In these detail cases you have to move the model while looking to understand it.

3D Printed Reliefs

Once fixed and solid I scaled 1D to push into a relatively high relief. Then I BooleanUnion a box onto the back. Here's the result - 9" high, 6" wide, 1.5" deep: 

Here's a three-quarter relief. Similar technique except rotating the 3D model first, then scaling along the axes of the CPlane. This is lower, about 1.3" thick total. 

Here's a side relief. Lower still - about 1.1" thick total.

The prints were done on a Stratasys Dimension 1200e, the one on the left. This is a ABS printer which requires support material.

The support material needs to be dissolved from the 3D print. It is soaked in a warm detergent bath for a few hours to do so.

Below you can see most of the darker support material is gone. A little remains on the edges - back into the tank. Also of note in this photo - that one was printed with the back plate flat on the printer bed. So the layers of the print look like contours across the face. Zoom in - you'll see this is a terrible idea. The print comes out just fine when printed vertically (face forward, not up).

Here's a comparison with the model, computer model, and 3D print.

In the Round 3D Print

The full 3D print was done on the printer below - a Stratasys uPrint. The printer took about 15 hours to complete the job:

Here's the finished print mounted on a Walnut base:


A Version Produced in Wood

Here's a post on CNC routing this same form in wood.


2 comments:

  1. Cool stuff, im so impressed that you were live modelling with the model in front of you, dont you think it would have been easier if you did it based of photographs.. ?

    - you prefer intous rather than cintique, i think the same way,, but my reason is not the the key shortcuts but that im cant see my model with my hand and intous pen in between my face and model.

    - is there a tutorial on making a 3/4 relief of a head bust ?

    - after you print the releif can we transfer it on brass ? if i have a project like this.. how much would that cost.

    i would like to see more of your jobs.. and be in touch..

    My name is Sultan, 38, im heading a designing section for a large org in Kingdom of Bahrain. where we do all kinds of graphics work and advertisement,, i primarily use max, and a little of zb for architechtural and gift concept modelling.

    thanks.

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    Replies
    1. Thanks. I definitely find it much easier to work from a live model than from photographs. Photographs really make it tricky because of the distortion introduced by the camera.

      I've used Shapeways.com a few times to 3D print. They can print in wax and then cast it for you in a variety of materials including brass.

      It's quite easy to do a 3/4 relief. Simply rotate the piece so the view you want is aligned with a particular axis (say X). Then scale down in X only. This pushes the 3D form into a relief. Try it out.

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