Using Edge Slide and Falloff to Fix Lip Topology in Modo

Posted on May 19, 2015 - category: character-rigging

Here is a new character I’ve been working on. I’m modelling him to be rigged and animated along with a face rig. The base sculpt and colors were done in 3D-Coat. I used voxel painting to lay in some rough colors without needing UVs.

Now I’m taking it into Modo to do some more technical topology clean up, and I’ll finish the UVs and texture maps in Modo. I’m quite new to Modo, but I’m already picking up some amazing new tricks, and I’ll show you a bit in this post.

Some of my original rough sketches done in the online sketch tool, Scribbler

While this guy sort of resembles a turtle with his shell, I’m going to make his skin translucent and colourful like a frog.

Editing the Mouth Topology Using Edge Slide & Falloffs

3D-Coat has some amazing topology tools, but I find it a bit difficult to do very precise and complex operations in very small areas like the mouth cavity, lips and eyelids. I feel a lot more confident to make these changes in Modo. You have great topology tools as well, but it is well integrated with all of the snapping, falloff and modelling operations. So you can seamlessly switch between sculpting and modelling, and do things like Bridge or Bevel or Thicken.

You can even copy/paste polygons to make new geometry like eyebrows or clothes or break apart existing geometry to make big fast structural changes. (With all the powerful features of Modo, the simple ability to cut, copy and paste geometry as easily as text is one of my favourite parts of the whole program.)

First I need to make a topology fix in the corner of his mouth.

I went from this topology with square poly-turns right in the corner of his mouth:

To this, with a radiating pattern around the entire lips. The first version might have worked, but having the radiating rings is more flexible for making cartoony lip shapes like puckering and a small mouth OOH. Making this change was relatively easy with the Topology Pen.

BUT, now there is a slow turning of the lips. The outer edge of the upper lip slowly rolls inwards, so that by the time it gets to the bottom, it is inside the mouth. I’ll fix this.

I’ll use Edge -> Slide to handle this. The amazing thing about Modo is that all of these poly modelling tools integrate with snapping and falloff. So you can use Linear Falloff so the Slide happens more near the center, and less towards the corner of the mouth.

First I drag a Linear Falloff which you can see as a triangle with two transform gizmos in the following image. Then turn on “Ease-In” in the falloff’s properties. Then any modelling operation I do has a nice soft falloff.

This is powerful!

After sliding all the edges of the lip outwards a bit, I now have some nice clean lip topology!

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