Erasing triangles

advice

#1

Hi,
after drawing what you see in the image (a schoolyard game made imitating a small pyramid made by tires and sand), I realized that in between the external “tires” I should delete the brown triangles (see image)

but don’t know how to do it. I tried to intersect two contiguous tires but nothing happens, so perhaps this isn’t the right way. (All the items are components. I tried to explode the big brown cylinder that makes the base of the pyramid, but didn’t work also).
Regards


#2

You could try selecting the brown cylinder and use Intersect with Model to create a vertical line at the meeting point of the tyres. You’d have to do that inside the component and then try erasing what you want before coming back out. This assumes there is no gap between the tyres.


#3

Thanks, I closed all the gaps “by hand” in between tires and it worked well, a bit cumbersome, but it worked!


#4

By the looks of your image, it looks as though the structure needs moving upwards onto the red/green axis. At the moment below the ground plane, the shadows won’t display correctly if you turn them on. Looking good though.

FWIW, This is roughly how I did the centre parts, minus scaling the tyres. I used the model origin as an anchor to rotate around and tried to avoid creating too much geometry that would need deleting. The tyres have to match up “tangent” with no gaps for it to work of course. I modified the tyre components later.


#5

Thanks IanT it doesn’t look difficult to do…(even for me…)
Best regards


#6

Your welcome, I’m not saying it’s the right way to do it, it’s just they way I did it so I thought I’d share it. There’s so many ways to do things in SU, there’s probably better ways too.
Good Luck.


#7

By the way, how do I draw the side of such a polygon so that it measures a specified length, eg the diameter of a certain type o tire(/circle)?

Also I am not sure how to reproduce the behavior of the Rotate function/tool…when I point the next corner of the polygon after drawing the first circle, the polygon rotates as well!


#8

Start with any size polygon, it doesn’t matter as you will resize it later after the array of circles.

The number of sides for the circle has to be a multiple of the sides of the polygon, as shown previously by Jimhami42. For example for a 5 sided polygon use a circle of 30 sides. Just make sure to get the circle endpoint onto the midpoint of the polygon to get the array right.

When you have 5 circles in position, they will need to be resized to your intended diameter. I used the Tape Measure tool as shown below. Click on the endpoint once, then the opposite endpoint, type in the desired diameter and hit Enter and then confirm the resize. Then Zoom extents to bring the entities back to fill the screen. Check the diameter with the tape measure tool and it should measure correctly.

There is a bit of a trick to the other layers because of this way resizing. I could explain that later, I’m in a bit of a hurry right now.

I’m not quite sure what’s happening there, it could be a few things. Make sure you group the polygon, then make the first circle a component. Make sure only the circle component is selected, then do the copy rotate and make sure you hit the CTRL key when starting the rotation.

Hope this helps.


#9

Hi, ok, thanks again for all the explanations. I could now reproduce the drawing following the indications. Provided. Still I’d like to know about this trick you were talking about, when you get a chance.


#10

The problem I came across were that if I resized a tyre, then the previously made tyre stack would also be resized to the incorrect dimensions…

(None of this has any connection to SketchUp layers which control visibility.)

The way I got round it were to make a tyre layer at a time, make the complete thing (tyres and sand) into a component being sure to set the component axis in the centre and then delete it. YES delete it. Even though it is deleted from the model space it still remains in the “In model components”, unless it is purged from the file.

I then made the remaining tyre layers, now able to resize them without affecting the sizes of the ones I had deleted from the model space, great stuff.

When I finished the last one, I made it a component (setting the axis) and deleted that. Then staring with the largest I brought them back in to the model space, stacking them up. Here`s the last part…

Its probably much easier than I make it sound, although I have tried to explain as clearly as I can. Again, its probably not the “be all and end all” it`s how I found a way around the problems I came across.

Hope it helps.


#11

Hi Ian,
actually today I just realized about this and was going to ask for advice…Thanks again!


#12

It were only a matter of time! Good luck.


#13

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