How to split an entity into segments

ollie2893

Hi,

I am new to SketchUp, and am generally very impressed with the user interface. I must have missed a trick watching the on-line tutorials, though. Here's my problem:

I draw a circle. By default, it does not have enough segments. So I open the Entity Info and up the segment count. Done. Great.

I draw a polygon, same center point as circle. If I now extend the radius of this polygon just beyond that of the circle, then I get the effect that I want: I can now use the Eraser tool to delete every corner that protrudes beyond the circle, and every arch that protrudes beyond the face of the polygon. I end up with a shape that looks a little like a classic pencil shaft.

However ... the polygon I get by default does not have enough sides. So before I can start with the erasing, I need to up the segment count in my polygon. Once I did this thru the Entity Info, though, the manipulation that I described before no longer works because now the polygon has been promoted to an entity in its own right. No longer are there intersecting elements between the circle and the polygon. And it is no longer possible to erase individual segments. I can now only erase the polygon or the circle in whole.

I have worked out that on the entity context menu, there are Divide and Explode options. Unfortunately, Divide blindly halves the circle, and Explode blindly shreds the circle into small segments that may or may not intersect with the lines of the polygon.

I have also worked out a work-around: I can create a dummy polygon first, change its segment attribute, delete it and create the polygon I actually want. That seems to do the trick. However, this is slightly bizarre so I thought I ask what the official method is to revert back from a geometric entity to a segment composition?

Thanks.

remus

you can adjust the number of segments in your polygon before you draw it by simply typing the number of sides you want and pressing enter, it sounds a little weird but makes sense after youve done it a couple of times.

Gaieus

@remus said:

typing the number of sides you want...

followed by an "S" (for segment) - otherwise it will be the radius.

So say you want an octagon with a 10 cm radius, you do this:

select the polygon tool
type 8s and hit Enter
type 10cm and hit enter
(or if cms are your default unit, you can spare typing that and only type 10 and hit Enter)
Do the same for circles - except in step 1 you select the circle tool of course.

remus

you dont need the s if you put it in before you do the first click to place the centre of the circle

ollie2893

Ok, thanks, that works, yes. So just to complete this subject, your suggestion sort of works around the issue. Are we saying that there is a way to go from segments to entity (via using the Entity Info) but not from entity to segments?

Gaieus

@remus said:

you dont need the s if you put it in before you do the first click to place the centre of the circle

Doh.

Get away, Remus!

Jean Lemire

Hi folks.

Don't forget that you can use "Explode curve" to transform a circle or polygon or freehand curve into a serie of edges. After that, you can delete selected edges withoout erasing the whole lot.

Just ideas.