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seeking clarification with TWIST function

ZBrush Usage Questions
#1

seeking clarification with TWIST function

Hello dear fellow zbrushers.

I have a simple shape that I transformed in zbrush using the twist function. I like the shape, but my problem is that I need to replicate the exact twist function in Rhino, so I can have the modified form as a nurbs objects.

The reason why I am having trouble doing this is because Zbrush twisted my model in an irregular way (I like the way it looks but it seems that the twist axis is not straight down the z axis), and I’m having a lot of difficulty figuring out:

  • the start of the twist axis,
  • the end of the twist axis,
  • the angle or first point of reference
  • the second point of reference

this is the information which I need to replicate the twist function with my nurbs object in Rhino.

Is there anyone out there who could give me a hand with this. I would really appreciate some help.

warm regards,

CdeV

#2

Helix3D?

#3

Doug, are you suggesting I use the Helix 3D primitive as a reference because that corresponds to the twist function path?

#4

Yes, in Initialize are a bunch of parameters you can tweak and watch it update, when happy hit Make PolyMesh3D. :wink:

#5

Thanks for the advice Doug, but I already have a 3d model, which I loaded into zbrush and I am applying a deformation to it. the twist function i am talking about is a deformation on this existing form and I need to replicate the twist deformation in rhino…do you get what I am trying to do?

#6

Once upon a time I downloaded a demo of Rhino. As it was out of my budget at the time(and still is) I don’t have it or experience with it’s usage. There must be a twist modifier you can access parameters of.

#7

Thanks for the advice Doug, but I already have a 3d model, which I loaded into zbrush and I am applying a deformation to it. the twist function i am talking about is a deformation on this existing form and I need to replicate the twist deformation in rhino…do you get what I am trying to do?

I do and I think that you will find that ZBrush does this in an interesting way, I also think its going to be different from Rino, but I am not sure of that.
In ZBrush Twist seems to be more like Smear around a point, its VERY odd. The point its smearing around is in the exact center of the Canvas in X,Y and Z.
Not knowing what Rino does I can’t actually help with that, but if you show your object, the one you like to other Rino people they might be able to help more.
The Deformation Palate in ZBrush is very different from most of the other software I have seen doing things with the same name. Twist being more like smear and bend being crush and fold being a good example of this.

Just a thought, but if you put up an image of it I might be able to figure it out in Blender, but thats a long shot, Blender is more like Rino I suspect.

#8

MealeaYing!! THANK YOU for your reply…finally someone who gets what I am talking about :smiley: exactly, there is a kind smear effect as well as a twist…and it doesn’t twist from a single point either, the whole form seems to twist around, without a fixed reference point. ok, let me send you an image, I would appreciate it if you could take a look.

#9

is there any information out there on the precise coordinates used in the Twist algorithm ?

#10

I think this is a question for Marcus honestly…

But…
It looks to me that the Deformation Palate forms a sort of “sphere of influence” around your object and the center of the canvas and that the sphere is a sort of gradient…
Does that make any sense at all?
It seems like the distortion is more intense as you go out from the center, and since you can move your object in relation to the center this can become quite pronounced.

Again, I think marcus would be better suited for this as I honestly dont know how to describe what Im seeing.

Also I didn’t get your picture, try DropBox or something?

#11

Is there a ‘screw’ modifier in Rhino? Maybe that would get you what you want.

#12

I don’t know if this will give you the result you want but, have you experimented with the Offset control in the Deformation panel before applying an action?

#13

He has the object he wants in ZBrush, he just wants to be able to make the same shape using Rhino.
That entails understanding what the deformation palette is actually doing, and so I think that Jacks suggestion is a good one, it will demonstrate more clearly how truly odd the twist feature is!

#14

thanks for all your help Jack, Mealea, and Doug, I really appreciate the ideas and advice you shared. I have a better idea of what is going on with the twist function in zbrush now, but i wasn’t able to replicate it in rhino unfortunately. seems deceptively complex actually. what i am trying to do now is to use the mesh i created in zbrush and reverse engineer it by converting to nurbs in rhino. maybe this works.