ZBrushCentral

Deleting internal mesh for SLA 3d printing

ZBrush Usage Questions
#1

I am relatively new to zbrush, but have been able to make some kinda cool stuff. The easiest way to get the look i want often times turns out to be just adding new polys using Insert(shape) brushes and then placing and modifying the shape. An example of this is in making a forced perspective diorama of a cornfield. To make the corn, i just did InsertCylinder, placed it, then shaped it to like like a corn stalk, then duplicated it and rotated it until I had subTools of dozens of corn stalks, getting smaller and smaller as they go further back to the vanishing point. It made for a cool effect. (I know I could have done a half cylinder insert and dynameshed and it would probably have blended it into one mesh, but that would also have killed some of the detail and made it a lot harder to quickly place about 1000 corn stalks.)

The problem comes when I want to have something done this way SLA 3d printed. My understanding is that in order to print properly it needs to be one unified mesh with no overlapping or internal mesh. Normally to fix this I merge everything into one subTool and hit Remesh - RemeshAll at the highest resolution with the symmetry turned off. It makes a new unified mesh subtool, deleting all of the internal geometry, then I simply project the detail of the original subtool onto the new one and I have a pretty good looking printable model. Not quite as high detail as the original was, but good enough for what I’m doing.

With these corn stalks however, I have an issue where the corn gets bunched together pretty tightly as the perspective shrinks. This means that when I remesh the corn, the back rows wind up looking like a rectangular blob instead of individual rows and no amount of adjusting the sliders will project the detail of the old subtool properly.

So basically I am not sure how to fix what I am doing. Is there a better way to get a unified mesh? Or is there an easier way to delete internal mesh?

#2

There’s really no reason you should be losing any significant detail with projection. Without pics I can only surmise you are trying to project high res detail onto a mesh of insufficient density to capture it.

A Dynamesh>Zremesher>Projection flow is going to allow you finer control than RemeshAll > Projection.

Merge your subtools into a single tool, then duplicate it. Use Dynamesh to fuse all geometry on the duplicate (ZRemesher will not fuse geo). If you don’t have much real nitty gritty detail, Dynamesh by itself at a high enough resolution may do the trick. Decimate down to printer-friendly levels.

See Joseph Durst’s thread on the quick prints he is doing:

http://www.zbrushcentral.com/showthread.php?199827-Thread-of-Madness-Joseph-Drust/page10

If your reference mesh contains more detail than dynamesh can handle (at least without melting your machine), then simply dynamesh it with the lowest amount of resolution required to capture the major forms (make sure things like fingers are separate). Run it through ZRemesher to create a new fused low poly base, which will generally give you cleaner topo than Remesh all. This will give you the opportunity to insert more geometry where needed. If you need finer detail in the “corn” area, insert some loops there. Likewise you can use the density paint feature in Zremesher to “paint” the areas you want more geometry in.

Subdivide the new mesh into a multiresolution mesh of sufficient density to capture all the detail from projection. Project detail from original mesh onto the new. Now you have the convenience of a fused multi sub-d level mesh with the detail of the old. Once satisfied, decimate and print.

#3

Wow, thanks. I have done dynameshing before and I swear I thought it didn’t work. (Like I said, I’m kinda new to zBrush) But I did what you said and it worked. I am utterly befuddled. Thanks a bunch for the suggestion, this has been a giant help.