# Autofold in Shapr3D

Hello Shapr community.

I am trying to create a shape that requires something similar to SketchUp’s Autofold feature, but using Shapr3D. Perhaps you can advise me on the appropriate way to do this?

Picture a rectangle 280 mm thick (the planer dimensions aren’t important for this example, but they’re MUCH greater than the thickness dimension). Connect opposing corners with lines to form an “X” across one face. Now, here’s the Autofold part…
I want the edges to remain 280 mm thick, but the intersection point to reduce to 170mm thick. So, each triangle should slope down from the edge to the center intersection. Is there a quick way to do this in Shapr3D? I’ve got a number of these rectangles to create for my project.

Thanks!

I believe there must be a way to push the intersection point downward but I don’t know these type of techniques.
2 other approaches, out of my head

• use a vol;ume susbtraction, your shape being a reactangle of same width (a plate) minus a pyramid upside down, which are both simpler forms. So create a rectangle of full width, then create a pyramid for the volume you are going to remove, have them in the same location and use a volume substraction
or
• create one of the triangle plate, with one thiner edge, duplicate it by doing a rotation with copy using the thinest edge as the pivot axe
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This was one method I attempted. I think it’s similar to what you described.

Yes. That was my thinking too, but apparently this cannot be done in Shapr3D. Your other two suggestions should also work, but the problem is they are cumbersome for my purpose. I have at least a dozen of these rectangles to which I need to apply this treatment, and they’re all different dimensions! To use the subtraction method, for example, I’d need to customize the upside-down pyramid shape for each differently sized rectangle. That’ll take me a while!

Regarding the second method, I’ve tried something similar…
I created the rectangle to the thickest dimension, selected the triangle and located my rotation axis on the thickest edge. When I attempted to rotate it down to the thinnest point in the center, only the cross-wise lines rotated. It had no effect on the solid.

I am probably missing something in your suggestion. Apologies. Let me see if I can demonstrate this with a screen capture, and post it.

Hi

You should be able to rotate the whole volume, hard to tell.
As for having different dimensions, how about doing a rectangle with a negative pyramid down to zero width in the center, use it at your base and copy it for any new item.
So when creating any random sized rectangle you
0) clone this first creased rectangle

1. extend it to the proper dimensions and thickness with the scale tool, including the crease depth
2. extrude the base of the rectangle to total thickness you’re looking for
Does this makes sense? I don’t know how to explain better without a video

After considerable experimentation, and correspondence with Shapr Support, I gave up and resorted to using SketchUp (SU) for this analysis. Here’s how I performed it in SU…
(Apologies for the coarse resolution. It appears video file sizes are limited.)

Overall, I’m disappointed that Shapr3D wasn’t able to handle this situation in at least a similar fashion.

Hi JLL,

Don’t give up! Here are 4 quick different ways to get the shape, if I understood correctly what you wanted to do.

First solution : extrude a first time, and then a second time with a draft angle that is automatically subtracted. You can then freely edit the shape, offset the face or change the proportions with the scale tool.

Second possible way : extrude a bloc and sweep the additional shape around the bloc.

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third solution : extrude a bloc, chamfer the top and then move the edges of the inner rectangle.

and last one : extrude a bloc, project the edges on the bloc, and then move the edges.

It takes some time at first to figure out how to perform some tasks, but then there is very often more than one way to do things with Shapr3D.

Hope it helps

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Hi PEC.

I appreciate you taking the time to respond to my issue. I’ve examined your methods, but unfortunately can’t make any of them work for my situation. If I attempt to Sweep the profile, I can only get around three sides. The fourth gives an error.

The other methods, as I understand them, used a similar approach which relied on creating an inner, offset rectangle connected to the outer rectangle. In these cases, when I positioned the inner rectangle at the appropriate height this created inward bevels (from 280mm at the edges to 170mm in the center). However, using the Scale tool to get these bevels to meet in the center forming the drain resulted in lowering everything to the 170mm height, and I lost the bevels entirely.

These were great solutions, and inspired me to experiment further. Unfortunately, they still don’t seem to address the situation posed. Again, thanks for your consideration!

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By chance, is this what you’re trying to achieve?

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Hi JLL,

If I understand correctly now, you want the 4 triangles to meet at a single point.
@TigerMike not far from what you propose, but two triangles are actually trapezoid with one small edge.

Is it the shape you want to get?

Here is a quick way to do it.
In Shapr3D, there is no way to manipulate vertices, only edges or surfaces. So a solution is to create 4 bodies with the initial heigh of 170mm and then move the outer edges by 110mm to get the expected 280mm. Then union the 4 bodies. You can then move the outer edges if needed later or offset the bottom surface to change the overall thickness.

Best
PEC

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Excellent approach @PEC.
My next step was to show a variation which comes close to minimizing the trapezoid by using non-uniform scale. Your’s is more exact while mine is a close approximation.

Cheers, Mike

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PEC,

This was EXACTLY what I needed! Thanks!

So, you’re moving the two sets of triangles separately to establish them as unique bodies. This insures the sides extend all the way through the body, and aren’t just lines on the surface. I think that’s the key to doing this in Shapr, and where things diverge from SU.

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Hello TigerMike.

Your initial sketch is close, but I need for the diagonal lines to intersect at the center point to form the roof drain. I’ve tried using the Scale tool to decrease the center line as suggested by PEC, previously, but that didn’t seem to work very well for me.

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Hi JJL,

happy it solves the issue.
There are several other way to do the shape.
If you prefer sketching the profile, here is a way.

By the way, you mention a roof drain, if by chance there is a hole at the intersection point, then this open new possibilities, as the hole is an edge you can move directly.

Best
PEC

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PEC,

While the ability to sketch the profile is nice, and may allow me greater precision in the future, I think your original four-body method is quickest for my current situation.

While this is a roof drain, I’m uncertain of the center pipe dimension. So, treating it as a vertex is the way to go for now.

Thanks again for your consideration on this!

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