Anim8or Community

General Category => General Anim8or Forum => Topic started by: ronaldefarmer on April 19, 2020, 10:41:40 am

Title: Smoother Subdivisions
Post by: ronaldefarmer on April 19, 2020, 10:41:40 am
Hi Anim8ors,

I would like to be able to create subdivisions from extruded objects without having the odd "tessellation" effect seen in the attached image. Thanks for any help you can offer.
Title: Re: Smoother Subdivisions
Post by: ENSONIQ5 on April 20, 2020, 02:23:38 am
Before subdividing it is important that all faces have exactly 4 sides.  Triangular or 5+ sided faces will not subdivide cleanly.  End caps on objects extruded in Anim8or are usually comprised of triangles, spending some time removing superfluous lines to ensure all faces are 4-sided will result in smoother subdivisions.
Title: Re: Smoother Subdivisions
Post by: FWL on April 20, 2020, 03:48:07 am
Hi Ronalddefarmer,

I am no expert but like ENSONIQ5 said the tesselation proces of the start and end caps causes poles right on the edge of your shape. This is what causes the 'pulling' creases on your shape. You could do the extrusion of the spline with the option marked 'Don't tesselate caps' . This way the start and end cap consist of one face. This face will probably be 'overhanging' the shape because of the irregular shape. So then you'll have to put som edges acrosse the top and end cap to support/reinforce the shape. Then you could make a ring of quads around the edge as a control loop for the outer edge of the shape. You can achieve this by group extrude the faces by an amount of zero and then scale the newly formed faces. Again because of the irregular shape and the location of the centre of scaling of the group you will probably have to scale the faces individually because otherwise you'll create overhanging faces again. Then finally you can put in a control edge on the edge ring that was made in the direction of the extrusion to reinforce the edge in this direction. Then when subdivided it will keep its shape and have a clean edge. To illustrate my some what confusing story ;-) a screenshot of the mesh and the subdivided version. UV-mapping this kind of mesh will probably be a challenge without getting distortion.

I hope this helps!

Title: Re: Smoother Subdivisions
Post by: Steve on April 20, 2020, 01:51:48 pm
Anim8or uses Voronoi tessellation on the faces which makes triangles. It uses Catmull-Clark subdivision which works for any input geometry but works best with 4-sided faces. So as ENSONIQ5 said, it's better to use 4 sided faces whenever possible.
Title: Re: Smoother Subdivisions
Post by: ronaldefarmer on April 21, 2020, 12:54:50 am
Thanks for explaining, everybody, that makes sense. I did not understand about the triangular faces. I just noticed that extrusions did not subdivide well. The main reason I asked is because I saw an example once (a long time ago) where someone had made "liquid" text objects. They were very smooth and clearly they were subdivisions. I have tried for years to figure out how it was done but to no avail. Subdivision are my favorite because they look so cool with environment maps.