Modeling a star with adequate geometry...

#1

Hi all,

What would be the best way to model a 5 point star shape - it will need to, ultimately, be an editable poly with enough geometry to take into mudbox for sculpting. Would love to know how to do this so that it would also be able to handle turbosmooth.

I’ve tried the spline and extrude and it works but can’t seem to be clean geometry on the face of the shape. Didn’t have much luck shoring up the edges for subdivision either.

I also thought about creating a 3 sided cylinder and using array to get them in the star shap but got lost in the math and overlapping faces. :blush:

Thank you for any suggestions.
Daf

#2

I feel like I’ve modeled a star before so I gave this a shot with how I would’ve, and it works …OK, but not great. Since the star has 5 points, you would basically want to double that and start with a 10-sided object, which is what I did for this cylinder. I went around clockwise selecting every other point (2 o’clock, 4 o’clock, etc…) and uniform scaled in on X and Y.

Then when the shape was set, I used Swift Loop on the X axis to give it supporting edges and since SL was being a PITA on the Y; I just used Connect, set the Constraints to ‘Edge’ mode and moved them on their local axis to the tip of the point. Same thing for the ones that I moved towards the center of the star.

Here’s how it looks when brought into Mudbox as a base mesh

Holds up surprisingly well, until you subdivide it one/two/three times when you get something like this (apologies for terrible wireframe coloring, I didn’t realize Mudbox’s default background color was white not black :()

Four subdivisions seems to be the magic number which gets it back to full quads, so it’s …a sort of working solution?

#3

Ah, well done, man! That looks pretty darn good! I’ll give it a try! Thanks! :slight_smile:

#4

Just in case others may search for this in the future I’ll list some of the other suggestions I’ve gotten on other forums.

Here is another good one from Steve Curley over at the Area that works very well!

  1. Create a Star shape, radius1 100, radius2 40, points 6. Move it to the origin.
  1. Convert to Editable Spline. Orbit the object (Perspective View) so that one of the outer points which lies exactly on one of the X or Y axis is pointing away from you.
  1. 2D Snaps to Vertex. Create Line (Geometry rollout) from one of the inner points (next to the point furthest away) to (roughly) the origin to the inner point on the other side (of the point furthest away).
  1. Select the vertex nearest the origin and move it to the origin. You now have a Diamond shape. Select the 4 segments surrounding the Diamond, Ctrl+I (invert selection), Delete.
  1. Area Select the vertex on one side > Weld. Repeat on the other side. Select all the vertices (Ctrl+A), right-click one of them > Corner.
  1. Exit SubObject levels and add a Surface Modifier, change the Patch Topology Steps to 0. Sometimes the poly will be upside down, so right-click > Object Properties > Backface Cull. If upside down click the Flip Normals option on the Suface modifier Parameters rollout.
  1. Convert to Editable Poly. Select the Border, Edit Border rollout > Crease 1.0. Shift+Move the border down in Z, change the Crease again to 1.0. Move the Border to -1 in Z (use the spinner at the bottom of the Max window).
  1. Select the Poly on the top, Detach to Element as Clone. Flip (Edit Polygons rollout) then move it down to -1 in Z as before.
  1. Select all the Vertices (Ctrl+A) then Weld. With the object oriented as earlier with the point furthest away and the origin closer to you, select the vertical Polys either side of the point at the origin and delete them.
  1. Select the 3 remaining vertical edges and change the Crease to 1.0.
  1. Exit SubObject level, select the Rotate tool, then the Array tool. Change the Type to Copy, in the Incremental (top-left) section of the dialog change the Z value of the Rotate line (the middle one) to 60 (360 degrees divided by the original number of points on the star), change the 1D Count to 6, click the Preview to see if it’s worked correctly then click OK.
  1. Attach List (button next to Attach on the Edit Geometry rollout) and select all the “Star” objects and click OK. Select all the Vertices and Weld.
  1. Turn on NURMS subdivision, turn off Isoline and Show Cage. Increase the number of Steps appropriately.