Follow me not working as expected

followme

#1

Hi my friends! Please check this simple object. aa.skp (197.3 KB)

I selected the red face (in the object of the right) and made it follow the arc above the object. The result is the object in the left. You can see that an undesired part will appear (I made it green so you can see). How can I solve this problem?


#2

Your topic caption indicates that you had an expectation. What did you expect ?

(It would be better to insert images clips from the model, rather than make people download and open it. For example, I cannot open it this machine because it was created with 17.0. version of SketchUp.)


BTW, SketchUp is now at version 17.2. Download new versions.


#3

The Follow Me tool positions the profiling face at a right angle to the first edge before performing the operation. If you use a full circle and rotate it so that the edge of the arc is vertical (in your case), then the Follow Me tool will behave as expected.


#4

You are right that SketchUp behaves quite oddly when it comes offsetting and follow-me-ing curves. The convention for segmented curves is that the vertices should be on the curve which also means the offset distance should be measured vertex to vertex on a curve. This is the convention SketchUp uses when displaying arc radii in Entity Info. However, SketchUp doesn’t care of whether edges form a curve and just offset them as if they were straight edges, meaning the offset distance is measured perpendicular to the edges, not vertex to vertex.

By rotating the circle as Jim suggested and having “half” a segment at the ends you can work around this issue. However it means it’s now the midpoints of the segments and not the vertices (endpoints) that represents the curve. If you are interested in making precise models this means the radius in Entity Info now isn’t to be trusted since it’s measured vertex to center point, not segment midpoint to center point. Instead you manually need to scale the arc to the desired radius using scale tool (if you care about this precision).

I suppose there is also a plugin out there with an offset and extrusion tools that honors curves and creates gives the expected result but none that I know of.


Follow Me along an arc.... issue?
#5

I think this illustrates the expected and actual behavior of offset and follow me.

EDIT: Feature request for fixing this has been made here: SketchUp : Wish List


#6

Thanks I will download it right away!


#7

Could you please tell me so how should I do it? I didnt understand very well what you said BUT your last print is EXACTLY what I am looking for. How do I make my oval shape exactly as you did?


#8

Thanks a lot for the diagram. I think what you are trying to say is that if I use the follow me I should make it start and finish in a straight vertice?


#9

There are many ways to accomplish this. The main thing is to use a circle that is essentially rotated 1/2 of a segment. In the following GIF, I used 48 segments for both circles. 360 deg / 48 segments = 7.5 deg / segment. You could rotate the circle 7.5 deg to get the ends perpendicular. As @eneroth3 pointed out, in some cases the radial distance to the middle of the segment is important since it is not the same as the radial distance of the vertex. The approach I used didn’t make any difference in this regard.


#10

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