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How can I make grooves in a sphere. If I use the Subsurf modifier, the edges don't keep sharp. And if I use a crease of 1 I loose the smoothness of the sphere.

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Here what I get using crease at 1.enter image description here

Here the illustration of the problem I encounter. Left is only 'Mark Sharp' applied, middle is only 'Edge Crease of 1', right is 'Mark Sharp' and 'Edge Crease' both applied.

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Artefacts appear.

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Grobby
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1 Answers1

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You can add a sharp 'crease' to a model by using the edge split modifier. I see in your screenshot that you already have the modifier applied.

The edge split modifier will treat sharp edges as qualified to split, regardless of the Edge Angle specified in the modifier. Edge Crease forces a pinching effect to be applied to the geometry generated from the subsurf modifier. By combining these two, you can get a sharp edge while maintaining the smoothing effect of the subsurf modifier.

In edit mode, select the edges you wish to effect and press 'Ctrl+E' to open the Edges menu. Select 'Mark Sharp'.This will split the edges to create sharp edges in the shading. Sphere with sharp edges

Afterwards, select those same edges and the edges connecting the corners of your grooves. Use 'Ctrl+E' again to open the Edges menu and use the 'Edge Crease' option to pinch the geometry into a sharp profile, effectively ignoring the rounded edges from the subsurf modifier. Groove represented in a subsurfed sphere.

Here is a sphere showcasing the different effects. Left is normal geometry, middle is 'Mark Sharp' Applied, and right is 'Mark Sharp' and 'Edge Crease' applied.

Comparison between edges.

Thomas Pendergrass
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  • Very usefull.... It allows a control of the edges with the Subsurf modifier. How to apply this to the model I'm trying to reproduce? I tried to extrude the edges marked as sharp but the vertical edges don't keep their sharpness. – Grobby Nov 21 '16 at 18:04
  • I rewrote my answer to better reflect the issue you are trying to resolve. – Thomas Pendergrass Nov 21 '16 at 18:27
  • What is the use of selecting 'Mark Sharp'.before applying the Edge Crease? Maybe I'm doing something wrong but applying an edge crease in the corner raise the intersection of the edges creating a point. – Grobby Nov 21 '16 at 18:38
  • You can apply the 'Mark Sharp' and 'Edge Crease' in any order. Mark Sharp splits the edges to provide the sharp look. Edge Crease allows you to pinch the subsurf geometry to follow the sharp edges instead of smoothing them out. Keep in mind that unlike Mark Sharp, Edge Crease takes a number value to set how intense the crease is. After selecting Edge Crease, and before you click to confirm the crease, you can drag your mouse to increase or decrease the effect, Or you can press the number one and click to apply the maximum crease. – Thomas Pendergrass Nov 21 '16 at 19:01
  • I updated the post. I don't know what I'm doing wrong but as you can see there is no difference between the 'Mark Sharp' worflow and the 'Mark Sharp' and 'Edge Crease' both applied. Thus some artefacts appear on the intersections between edges. – Grobby Nov 21 '16 at 22:11
  • I cannot see the update to the post. Perhaps you can upload a new screenshot to imgur.com and share the link? – Thomas Pendergrass Nov 21 '16 at 22:18
  • Let us continue this discussion in chat. – Thomas Pendergrass Nov 21 '16 at 22:18