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Twitchy Boole?
Posted: 22 March 2020 11:28 PM   [ Ignore ]  
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I have a pretty simple house model that I want to cut away using the Boole. But it’s extremely twitchy: polygons appear and disappear in a spastic pattern (and new ones pop in and out) so there’s no way I could animate the cut moving around - which is the whole point.

Here’s a link to the model:

https://adobe.ly/2WHvjEC

Also problematic - the Boole doesn’t consistently create a cap between the faces of the cut model - that is, if I cut through a solid object like a wall or floor that has thickness, I get the top and bottom polygons (or front and back) with the interior visible. Which pretty much defeats the objective (i.e. cutaway views). Increasing the number of polygons in the cutting cube helps somewhat, but it’s still very twitchy. And if I boost the count too high, the whole model disappears.

I suspect the problem is too many independent objects (or too many instances) in the Null. I can simplify somewhat, but I really do need the parts to work independently as much as possible.

Do I have to make a Boole for each component and control the movement of the cutters using a constraint?

I know the volume builder is a better Boole, but I again need to keep all the parts separate and available. 

Maybe I’m just holding it wrong… :(

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Posted: 23 March 2020 04:23 AM   [ Ignore ]   [ # 1 ]  
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Hi mford610,

There are certain limitations to Boole. Mostly when the geometry has some equal “levels”, to use a more general term.

Often this can be overcome by turning an element by 1º or (preferably) setting the segments, points different.

To have just a large group under a null for part A and then only six polygons (as a cube) cut through it, will most likely not work. One of the main problems is easy to spot when parts of the Groups A (or B) intersect inside the same group. Yes, even that might work sometimes… But indeed not suggested.

I have sorted your model, increased the point counts, and found another problem. Also here, that can work, but mostly not at all: non-volume objects or parts with three+ polygons sharing the same edge. This happens in your windows a lot.
Also, if you boole an object and then use instances of that booled object to be booled again, that will definitely fail. Then still, sometimes also that seems to work. Again, not a good way to set this up.

So, with all the blurry advice, I hope you got some ideas.

BTW, I have not remodeled nor fixed the windows at all (nor the door). I just added a Gradient into the Alpha Channel of the materials and modeled this 3D Gradient set to work, via Xpresso.

I have placed one object on a green Layer, this is the one that rules the scene (Cutter.Move.Me)

Something is in this scene that caused crashes. I copied all into a new scene file and couldn’t recreate the crashes. So, set your auto back up to active. But I guess that is, of course, on.

Your file
https://www.amazon.com/clouddrive/share/uFzv0APaJAAggCJzFgEOhtqEqJ8R0eoPggUvk8CEZgh

All the best

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004
Maxon Master Trainer, VES, DCS

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Posted: 24 March 2020 12:53 AM   [ Ignore ]   [ # 2 ]  
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Ah! Of course. Sorting the components into non-overlapping “layers” makes perfect sense. And the sloppy mesh in the windows and doors is certainly a problem. I thought I would save some time by borrowing a window from a house in the content browser. They look fine if all you’re going to do is populate a background neighborhood. But not in a “real” construction. I’ve spent at least twice as much time modifying it to work than it would have taken to build one from scratch. Learned my lesson there!

I will have to give some study to the use of gradients to modify the characteristics of the Boole function. The end result is quite clean to my eye (at least compared to what I was getting before). So it’s an excellent solution to have on hand in an emergency.

Thank you! I’m back in the game.

Mark

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Posted: 24 March 2020 01:31 AM   [ Ignore ]   [ # 3 ]  
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Hi Mark,

Yes, preparation is often the best way to save time. But of course, I understand the idea of taking what is available. In Arch-Viz, the data is usually not as good as a modeler could provide it. Hence why I went with it to show you the way to get these small parts into the mix, without slowing down the whole thing.

I can’t help myself, but I got the impression that I have to share this file:
https://www.amazon.com/clouddrive/share/tQa5kZVJtWgnUNUXj1oJ09aiYa8QBzsttLmjtaPHHJX

Please pick the MOVE.ME! object and move it around. Note also that there is zero Boole in the scene. So we move an alpha channel around. If that is connected to a boole (cut) object, then the impression will be that also these little parts are booled. It is just a visual-effect, not anything based on polygon alterations, etc.

I know you will love this, especially for anything small and high-density meshes. It cuts through them like a “hot knife through butter”.

Please let me know if there is anything else. I’m happy to look into it.

Cheers and stay healthy

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004
Maxon Master Trainer, VES, DCS

Photography For C4D Artists: 200 Free Tutorials.
https://www.youtube.com/user/DrSassiLA/playlists

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