topic Re: Surface Area of a non coplanar polymesh face in AutoCAD Forum

Surface Area of a non coplanar polymesh face

Anonymous — Wed, 08 Feb 2017 14:08:29 GMT

I've been tasked with finding some numbers for the estimators in my company to base their estimate off. The problem is that one of the predominate features of the building is a large smooth, curvy, arch-type structure that goes around the building and over the front entrances. The shape of the arch is made up of some surfaces which are flat, regular shapes, and others with are definitely NOT flat or regular (non coplanar surfaces), and the ones which are not are giving me some issues.

We need to find the surface area in order to price materials and what not. The problem I'm running into is that I can't find a way to find the surface area of a non coplanar surface. We were given a model in Revit by the Architect, and I've tried converting it to AutoCAD and working from there but I haven't had any luck so far.

I considered flattening the non coplanar surfaces, but it flattened the whole shape, rather than just the one surface which I'm working on. I tried the AREA command (which didn't work because of the surfaces non coplanar-ness), I also tried MEASUREGEOM command, again unsuccessfully (AutoCAD said the selected object doesn't have an area... weird). I'm pretty sure all my issues have been because of the non coplanar nature of the surface but I don't know how to work around that.

Plllllllease help!!

Re: Surface Area of a non coplanar polymesh face

john.vellek — Wed, 08 Feb 2017 17:06:40 GMT

Hi @Anonymous,

Can you share the file? My first thought is if you want to do this in AutoCAD, is to use data extraction. I am happy to explore the possibilities if you can share even a a sample.

Otherwise, it might be best to keep the file in Revit and try to get the takeoff done there. I haven't done anything like that in a long time but I can probably tap some resources if you want to try that route.

Please select the Accept as Solution button if my post solves your issue or answers your question.

Re: Surface Area of a non coplanar polymesh face

john.vellek — Thu, 09 Feb 2017 23:12:59 GMT

HI @Anonymous,

Are you able to share a sample file? I am happy to delve into this issue for you.

Re: Surface Area of a non coplanar polymesh face

leeminardi — Thu, 09 Feb 2017 23:42:14 GMT

You did not mention the object type(s) you are dealing with. If you convert the surfaces to 3DFACES then convert those to REGIONS you can use the AREA command to calculate the total area even if the individual original faces FACES are not coplanar:

AREA A O

but you have to click each region individually. You cannot select them as a group.

I think it would be an easy VLISP program to enable you to select a bunch of faces and have it calculate the total area based on using the REGION and AREA commands.

~Lee