Re: determine the area on slice

From: Ray Bradford (
Date: Sat Mar 04 2000 - 01:06:29 EET


You can compute the area of the slice from the boundary edges of the slice
by adding up the signed areas of the trapezoids formed with each edge and a
reference line (such as a x or y line at 0).

For this to work, the edges must all be oriented in the correct way from the
triangles or other faces which must also be correctly oriented in 3D.
This will be the case for proper stl files and if you generate the edges in
triangle order.

The hole(s) will automatically be subtracted.

You compute the signed areas by computing dx, dy for the edge in the edge
direction (endpt - startpt).

Hope this helps,

Ray Bradford
At 03:11 PM 3/3/00 +1100, you wrote:
>Dear everyone
>Can anyone suggest me how to determine the area on each layer? Assume
>that we have many points on one slice.
>Best regards,
>Wanchai Rattanawong
>Industrial Research Institute Swinburne (IRIS)
>P.O. BOX 218, Hawthorn
>Victoria 3122, Australia
>Tel:(613)9214 5654 Fax:(613) 9214 5050
>For more information about the rp-ml, see
Ray Bradford Vice President, Software
Solid Concepts Inc
28231 Avenue Crocker, Unit 10 661 257-9300
Valencia, CA 91355 661 295-6877

For more information about the rp-ml, see

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