Changing range affects generated mesh

[GameJazz]

Hi
The extruded polygonal shape is only an approximation of the perfect geometrical shape that represents the extrusion. The less polygons, the worst the approximation is. In the video you send, the shape of the last couple of polygons (the last quad) matchs more or less the perfect shape depending on its length, and that's normal. The important thing is that when an extrusion is made of multiple parts, those parts match with each other. This is illustrated in the scene I attached to this post. It contains 3 generators, one that make generates a full mesh, and the two others that generate the same mesh but in two parts. Both shapes are coherent.
If you increase the resolution of the extrusion and/or disable the Optimize option and/or reduce the optimization's Angle Threshold, the generated mesh will have more polygons making what you described less pronounced.
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Have a nice day

Thank you for providing the example. 

"The important thing is that when an extrusion is made of multiple parts, those parts match with each other."
This only happens when the start/end of the range falls perfectly on the start/end of a new polygon. If the range is changed, you can see that the extrusion shapes don't match. This is problematic for the use case where gaps are needed in overlapping extrusions. I attached a screenshot to elaborate. Thanks again for your help!