brep volume is off by a factor of 8

I just dragged a brep volume & picked a simple rectangular solid. It's consistently off by a factor of 8. Any idea why this would be? I attached the gh def. so you can see better, it's self generating. Any ideas anyone? What am I missing here?

Thanks in advance.

-Mike

Attachments:

LumberVolWtCalc.ghx, 361 KB

Replies to This Discussion

Permalink Reply by Danny Boyes on February 8, 2011 at 5:54pm

It would appear that GH is doubling you inputs. 192*3*7=4032

Permalink Reply by Mike Calvino on February 8, 2011 at 6:41pm

Why would it do that? It's only doing it with the brep volume, not with the Fx3 widget. Any idea?

Permalink Reply by Chris Tietjen on February 8, 2011 at 7:41pm

You're using a centered box component so all of the input lengths are established from the center in each direction (+/-) ie. 12" input is -12",0,+12" or 24". Hence, since your thinking the dimensions are from one end the volume appears to you to be doubled. Just divide by 2 in the expression entry of the box component for each axis.

Chris

Permalink Reply by Chris Tietjen on February 8, 2011 at 9:16pm

Oops! My mistake above when I said your volume appears to be doubled. You're volume is off by a factor of 8 (two cubed) because each input dimension is off by a factor of 2.

Chris

Permalink Reply by Chris Tietjen on February 8, 2011 at 9:23pm

Here's the corrected def.

Chris

Attachments: