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#221

Hello, hope someone can help me with an ordeal I’m undertaking as practice with Zbrush.

I want to carve the inside of a short tube so it looks like a star-shaped gun-muzzle instead of a plain circle. Kinda like this:
[kaczl3.jpg]gun-muzzle copy.jpg

I thought by using an Alpha I could do it, but clearly the polys are being strained when I reach the other side, and what I want to do is to “cut” a shape into the cilinder while preserving a clean topo and a hollow from side to side. I don’t have any idea of how to cut down the shape, hence my question. Sorry if it sounds noobish and hope someone can help me with this :o

#222

if you have r3 you should be able to use a boolean operation

#223

I was just reading this thread yesterday…Might be what your looking for in this sketcbook thread…I think…:qu:
Link is right below.

http://www.zbrushcentral.com/showthread.php?p=666622#post666622

#224

Or you can hit it with topology and use the deformation features on it? I am on a Mac so I do not have access to 3.5 myself. Boolean would definitely be something to try. I have to wonder however; how hard it would be to clean up something like that afterward?

#225

super simple.
circle3d tool
initialize settings:
iradius1+2 =32
hdivide=10
vdivide=3
make polymesh3d
mask all
using lasso unmask 5 points in center to make star
deformation size, turn off z, size up about 30
you now have a circle with the star cut out of the center.
clear mask
store morph target.
offset in Z -100
morphtarget createdifference
you now will have a new tool that is a cylinder with a star shape in the middle

#226

I’d follow Spaceboy’s tip (gives a nice clean lopoly mesh), alternatively, you can also experiment with the Initialize settings of the Gear3D tool. [attach=185508]Gear3d.jpg[/attach]

Attachments

Gear3d.jpg

#227

Another solution would be to start with a Cylinder3D. In the below example I gave it an inner radius value of 30. Once you have your cylinder with a hole in the middle, do this:

  • make polymesh 3d
  • make sure perspective is disabled and snap your view so you’re looking down the “barrel” of the gun.
  • mask all
  • use the lasso tool to unmask every OTHER inner point.
  • deformations>scale, disable Z, scale to -60
  • unmask all

That will give you your star. Now hide the polys for the length of the barrel, so only the caps are showing, and use Geometry>Crease so when you subdivide, your cap edges will stay nice and sharp. You could take this a step further if you want and crease the edges for the star going down the length of the barrel. Alternatively, you could use Edge Loop with Crisp enabled. Your choice.

[[attach=185513]boolean.jpg[/attach]]boolean.jpg

#228

Wow, I hadn’t any idea that Deformation Subpallete was so versatile and that I could apply masks to primitives without turning them into polymeshes first :o had ingrained that primitive tools weren’t that editable at first

Precisely, I was experimenting with the Gear3D for a long while before posting here, because I couldn’t create the indentations within the Cylinder3D nor into the roundish one, but I never ended up with the square shapes that Etcher made :frowning:

I also applied what dustinbrown and spaceboy advised. I think my question wasn’t enough clear as I wanted to make a “star” shape like down the cilinder like the first gun-muzzle (in reality, a M4QD Knights Can for flash suppressing) but with the shape of a gear, like on the photo below the first one :o Anyhow, thanks because now I have an idea of how to make any kind of shape down a cylinder without making use of complicated alphas to mask and unmask the mesh :slight_smile:

:idea: Thanks Etcher for posting the settings you used for your gear :smiley: I was like “hell, I want the indentations SQUARE not pointy face desk” but then you shown me that I could modify the shapes by editing the curves (I think I couldn’t see that panel first because I needed to click those narrow buttons with orangey patterns first to make it to pop up).
After experimenting, I got what I wanted and used Deformation Size Z to stretch the cannon and get the basic shape to work later with the polymesh.

One thing I couldn’t understand is that after I CTRL+D to give the mesh a little more of res, the sharp borders of the tips collapse inwards and I don’t know how to prevent this :o
[no-collapse1.jpg]cannon-hipoly1.jpg

Attachments

no-collapse2.jpg

#229

you’ll need to do a poly edit, hide all but the end cap faces, then create an extrusion without moving, for a nice crisp edge
if you want to prevent the teeth from doing the same you’ll need to do similar on them as well to create edges that are very close or on top of each other

cheers

#230

thanks so much for share all this great info

#231

@wasa - As hard as I try to select just the end polys of one side, I always end with this kind of “echelon” just behind the flat vertical polys of the face of the hole, kinda like this:
[close-up1.jpg]close-up11.jpg
I rotated the second photo just to show from behind how these extra polys are forcely selected even when I just select the other ones.
Also, talking about how to extrude as you commented… I’m still working with an “initialized” primitive and I don’t know how to add those extra polys to the face by extruding it when I have limited tools at this point.
I know what you mean by extruding it of course. Just… I really don’t know what tool I should use in this situation, since it is a pre-polymesh primitive :o feels more noobish now I’m thinking about adding some sort of Edge-Loop or something like that to add some quads from the outter rim to the inner rim, thus preventing the collapsing by adding new geometry to the face, but… as I said, I don’t know how to translate this thought to Zbrush operations. It is the typical “I know what to do but I don’t know how to do it.” /orz

#232

Rumi.

To avoid the end-cap selection problem, crank down the ‘SDivide’ value
(in the gear tool) to something small before going to polymesh.

Then you should be able to select just the end-cap.

(Also check out the use of the ‘Crease’ and smooth buttons before sdivide?)

G.

#233

This thread is awesome! Thank you gabo1991 for starting such a helpful thread. I have an issue that some artists may have already come across and battled. I was hoping by putting my question in this thread (instead of questions and troubleshooting) it might actually be seen and answered :lol:


Does anyone know a way to utilize displacement with many objects in a scene without crashing Maya?

I am crashing Maya 2010. I have about 26 or so objects I would like to apply displacement maps to.

I already reduced the size of all the maps (except one, character itself) to 1024, the one larger map is only 2048.

Also, I am using the Mental Ray Approximation Editor. My settings are set to spatial, with 1 minimum and 5 maximum subdivisions. Fine is checked.

I found that lowering the max subdivisions will get it to render, but the details are not fully there.

I could un-check the 32 bit displacement and just use 16 bit… Not sure if this will make it work but its an idea.

Any help is greatly appreciated!

#234

Rumi, you can unpress the SMT button in the Geometry tab before you subdivide your model and it will retain crisp edges.

Unpress SMT, divide, maybe divide again, then press SMT and divide again if needed. Should retain the crispness of the shape.

Basically it creates creases for you (from what I gather) automatically using the base geometry. When you have SMT pressed, it applies a smoothing group with or without creases or edge loops depending on how you’ve built your model. If you don’t have any edge loops or indicated any creases, then you’ll get typical smoothing group…smoothing. If you unpress SMT, you get Zbrush happily making some “auto creases” for you and you can keep your nice mechanical hard-edge shapes if you didn’t bother to create edge-loops and creases manually.

Regarding extruding your initialized primitive, just select the faces you want to extrude, hide the rest, then click “Edge Loop” in the geometry palette (to create nice edge loops), then use the deformation palette and inflate in the xyz axes. This extrudes selected faces in the typical fashion you would consider as basic extrusion in any other modelling app.

Oh and last thing, check out the video in post #197 of this thread about 3 minutes in where he talks about selecting the Outer Ring using the visibility palette for that problem you’re having with that little selection issue, that may solve it easily.

#235

thanx a lot :slight_smile:

#236

I’m just browsing for some good and informative stuff and i found this thread interesting. Thanks to all for sharing it with us…

Keep it up…

#237

omgomgomg this is great!

#238

great tuts, thank you Gabo :+1:

#239

http://www.zbrushcentral.com/showthread.php?p=713504#post713504

#240

What the word on doing cavity maps with ZB4? I havent heard of doing something like that anymore since 3.1. I feel like i must of missed something.

Thanks!