设为首页收藏本站

晓东CAD家园-论坛

 找回密码
 立即注册

QQ登录

只需一步,快速开始

扫一扫,访问微社区

查看: 436|回复: 0

[其他] API可以识别拓扑中的孤岛吗?

[复制链接]

已领礼包: 40个

财富等级: 招财进宝

发表于 2021-1-12 12:48:37 | 显示全部楼层 |阅读模式

马上注册,结交更多好友,享用更多功能,让你轻松玩转社区。

您需要 登录 才可以下载或查看,没有帐号?立即注册

x

ID    31245
Applies to:    AutoCAD Map 3

Date    12/10/2001

This document is part of   Visual Lisp   Autodesk MAP DevNotes   MAP Topology   Topology Lisp   


问题:Can API identify islands in topology?

I have a problem in managing the links of a polygon topology returned by the
LISP function, tpm_elemadj. Is there any way (without performing geometric
calculus) to understand if a specific link in the list is part of an island,
assuming there is one?

解答:
Answer
There is no function that does this exactly as AutoCAD Map does not specifically
identify islands within a topology. However, you could use the tpm_elemadj
function and the tpm_elemget function to trace the polygon elements. The link
ID's returned by tpm_elemadj are those actually adjacent to the indicated
element. So for example, there could be many links meeting at a given node. If
the argument to tpm_elemadj is a centroid ID, then all the relevant links are
returned.

Thus if you have links left over after your trace, you know they are part of an
island. In other words; if the total number of links you have traced, from link
to link, is less than the total number of links returned by tpm_elemget, then
the result is that you have at least one island.

论坛插件加载方法
发帖求助前要善用【论坛搜索】功能,那里可能会有你要找的答案;
如果你在论坛求助问题,并且已经从坛友或者管理的回复中解决了问题,请把帖子标题加上【已解决】;
如何回报帮助你解决问题的坛友,一个好办法就是给对方加【D豆】,加分不会扣除自己的积分,做一个热心并受欢迎的人!
您需要登录后才可以回帖 登录 | 立即注册

本版积分规则

QQ|申请友链|小黑屋|手机版|Archiver|辽公网安备|晓东CAD家园 ( 辽ICP备15016793号 )  

GMT+8, 2021-9-21 08:14 , Processed in 1.013971 second(s), 25 queries , Gzip On.

Powered by Discuz! X3.4

Copyright © 2001-2020, Tencent Cloud.

快速回复 返回顶部 返回列表