More Cutting Component woes

Can someone spot what I am doing wrong here? I make a cutting component. Check that it works. Save it out. Start a new drawing and create a surface. Then I import the component and it orients to the surface fine but doesn’t cut it. When you look at it in the Component Browser, it has lost its cutting characteristic. So I reinstate it. Then drag it in and now it comes in in a different plane (which obviously also means it won’t cut a hole). I’m sure I am missing something.

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If you show the Details in Components, you’ll see that the thumbnail is side on. To get a face on thumbnail I had to make the window on the ground. Then it would save as and import, and behave itself.

Colin, I have been playing around with making cutting components all afternoon. They work for me in some contexts but not in others, which I expect means there is some stage in their creation that I have not fully understood. For example, here are two components that worked when they were created but one ceased to do so after re-importing. I still don’t know why one worked and the other didn’t.

I was beginning to think that it is only possible to have them work “in session” and you couldn’t save them out for future use. But a quick trawl through 3DW suggest that you can.

I can’t find much on the Sketchup website about creating them beyond the basics. There are one or two videos which are fine if you want windows and doors to protrude beyond the wall rather than be embedded in it as usual. I suspect it is when you start mucking about with the cutting plane that things go wrong. However, in the working component here I experimented with deleting the plane face and just left the loop. That seems OK.

Of course I am pretty happy if I get it to work but I’d really like to understand everything about it so that I can reliably do it time and again. Is there any really detailed guidance on their creation out there?

BTW, a lot of videos do rather unnaturally choose to create the window lying flat but a Sketchup Essentials one shows you can do either.

Square.skp (14.6 KB) My window.skp (11.7 KB)

The component’s positive z-axis direction is normal to the cutting plane. I think they draw the windows lying flat so they don’t have to set or alter the axes. Place them on the floor and they’ll cut the floor. Set to “Any” and it’ll cut walls without you having to set the axes.
Edit: Also probably because of what @colin said to make a face-on thumbnail.

The files in the GIF in your first post aren’t the same ones you uploaded here. In the GIF, if you open the Outliner I think you’ll see a nested component. You saved a file that contained a component. When you imported it, the file you imported became the component, which was not cutting. Inside that was your cutting component. Instead of saving like that, right-click on the component in the Components window and “Save As…”

You can change how far the window is pushed in or out of the wall by moving the component’s axes parallel to the z-axis. Of course if you move it so far that it no longer intersects with the wall, no cutting will take place.

When you start making a door or window and make a rectangular face drawn on a vertical face into a component, SketchUp will automatically place the component axes correctly and set the cutting property to “cut opening”-

OK, I think I may have cracked it at last! After all the trial and error I have done over the past 24 hours, I have come up with a set of rules and recommendations for reliably creating cutting components. I would be very interested to hear if anyone disagrees with any of them.

Some of these rules come from studying videos and printed advice but I have found the reasons for doing certain things thin on the ground (such as why you model a vertical thing flat - seems to be related to thumbnails). I don’t remember coming across anything that includes all these points in one place.

Here they are:

Rule #1 - Start with a flat surface larger than your component. This will correspond to your cutting plane. Model flat even if the component is something you would normally model vertically. It doesn’t matter if it stays modelled flat as you will be gluing it to a surface when you use it.

Rule #2 - Create the component as soon as you have enough geometry to do so, even if it is just a surface with a boundary. Then you can delete any surface outside it. This is more of a recommendation than a rule. It reduces scope for error in drafting.

Rule #3 - The loop around your geometry (its boundary) is effectively your cookie cutter that will be what cuts into a surface. You don’t need it to have a surface itself and the loop can be hidden, but it has to be there and it has to be continuous and coplanar.

Rule #4 - If your component has depth, you can extrude it up from the cutting plane, down from it, or even model away from it. You may want to group the main elements of your component. If you do, make sure to exclude the cookie cutter as this always has to be raw geometry inside the component.

Rule #5 - If you want to use the component in other drawings, save it from within the Component Browser. Do not use File>Save or you will lose its cutting ability.

Rule #6 - You can change the origin of the component by moving the Axes within it but make sure the red and green axes retain their original orientation. You are just moving their centrepoint.

Rule #7 - A Dynamic Component can have cutting ability but make sure the cutting loop stays raw. the rest of the component can be broken down into as many sub-groups as you like. The dimensions of the loop can be controlled by the overall dimensions of the component, ie. the parent group.

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Thank you so much for writing this mini-guide!

I have been pulling clumps of hair out all morning, I was down to the last patch before reading this, so thanks to you I’m not totally bald!

Thank you so much again and kudos for taking the time.

You are very welcome. I was in exactly your situation before I figured it out!