Intersection volume not correct bug?
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I run a simple general intersection rule, between a space and 4 walls.
Each wall is 2000mm long, 1000mm tall, and 1mm thick.
The 4 walls are totally inside the space, so I would have assumed the intersection volume is equal to the total wall volumes.
But it turns out the intersection volumes is reported only 50% of total volume.Is this a bug or am I missing something?
Attached a screenshot
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@Wing-Mang If you have a simple model that you could share, it’d help to find out what’s going wrong. If you don’t want to share it here in the forum, you can send an email to [email protected].
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yes sure. I saved the elements in separate file and here are the Archicad file (v26), the exported IFC, and SMC file with checking result.
The error is reproduced in this SMC file.Thanks!
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@Pasi-Paasiala Hi! is there any finding of what could be the problem?
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@Wing-Mang This is an ancient thing. The intersection volume is halved. The reasoning being that otherwise the sum of intersection volume could be larger than the total volume of the components. Maybe it is time to change this.
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@Wing-Mang I think the original reasoning for this is the following scenario:
You have intersections in slabs and you want to order concrete to be poured for the slabs to the site. You can deduct the volume of the intersections from the amount of concrete you order to the site. If you’d have the intersection calculated fully for each component, then you’d deduct too much concrete.
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@Pasi-Paasiala Thanks for your explanation on the reasoning behind.
However, it’s quite misleading and not intuitive. I wouldn’t have doubted the intersection volume if I was not doing some testing. The figure obviously differs from that in the description of the rule result, even though they both seem to refer to the same thing “volume of the intersections / intersection volume”.
Highly suggest the intersection volume in the report should not be halved.
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