请问用arx如何判断一点是否在面域内啊?

leemanzhuo

请问用arx如何判断一点是否在面域内啊?

XDSoft

最初由 leemanzhuo 发布
[B]请问用arx如何判断一点是否在面域内啊? [/B]

1、用AcDbRegion::getPlane(..)得到面域平面

virtual Acad::ErrorStatus
getPlane(

    AcGePlane& regionPlane) const;

regionPlane        Returns the plane containing the region

Returns with regionPlane set to the plane containing the region. If the region isNull, then regionPlane is set to the WCS X-Y plane.
Returns Acad::eOk is successful. If there is an error in the ACIS modeler while obtaining the area, then Acad::eGeneralModelingFailure is returned.


2、然后用AcGeSurface::isOn，判断点是否在平面上。


Adesk::Boolean
isOn(

    const AcGePoint3d& pnt,

    const AcGeTol& tol = AcGeContext::gTol) const;

pnt        Input point on surface
tol        Input tolerance

Returns Adesk::kTrue if the point pnt is on the surface within tolerance tol.equalPoint(). Returns Adesk::kFalse otherwise.

leemanzhuo

我知道用arx比lisp容易实现,但我对arx又不懂,请问能给出详细代码吗?谢谢了

HoboSoft

晓东的办法只能判断点是否在平面内而不能判断点是否一定在面域内，面域是有边界的，可以用如下办法，需要
BOOL PointInBrep(AcDbRegion *pRegion, AcGePoint3d Pt)
{
        if (pRegion == NULL) return FALSE;
        AcBrBrep brep;
        if (brep.set(*m_pRegion) != AcBr::eOk) return FALSE;
        AcBr::Relation relation;
        AcBr::ErrorStatus esbr = brep.getPointRelationToBrep(Pt, relation);
        if (esbr != AcBr::eOk) return FALSE;
        switch(relation)
        {
        case AcBr::kBoundary:// return CXtBrepUtility::eOnBoundary;
        case AcBr::kInside: return TRUE;
        default: return FALSE;
        }
}

程序需要包括 #include "brbrep.h"
和连接 acbr15.lib 库

lyousme

这是我自己参考别人的程序做的判断一个点是否在封闭的Polyline中，可能对看这个帖子的人有一些帮助,可能有些地方考虑得不够周到，请大家帮忙测一下

1. 
   
2. BOOL IsInClosePline( AcGePoint3d testPt,AcDbObjectId PolyLineId )
   
3. {
   
4.         AcDbPolyline * pPolyline;
   
5.         if(acdbOpenObject( pPolyline, PolyLineId, AcDb::kForRead )!=Acad::eOk)
   
6.         {
   
7.                 return  FALSE;
   
8.         }
   
9.         pPolyline->close();
   
10. 
    
11.         int start = 0;
    
12.         AcGeVector3d currentVector, previosVector, contrVector, refVector;
    
13.         int count = 0, countDir = 1;
    
14.        
    
15.         AcGePoint3d point;
    
16.         pPolyline->getPointAt(start,point);
    
17.         previosVector = point - testPt;
    
18. 
    
19.         for (int j = start + 1; j <= pPolyline->numVerts() ; j++)
    
20.         {
    
21.                 if ( j == pPolyline->numVerts() ) j = start;
    
22.                
    
23.                 pPolyline->getPointAt(j,point);
    
24.                 currentVector = point - testPt;
    
25.                 if (contrVector.isZeroLength() && !previosVector.isEqualTo(currentVector))
    
26.                         contrVector = previosVector + currentVector;
    
27. 
    
28.                 refVector = previosVector.crossProduct(currentVector);
    
29.                 if (previosVector.angleTo(contrVector, refVector) < previosVector.angleTo(currentVector, refVector))
    
30.                 {
    
31.                         count += countDir;
    
32.                         countDir *= -1;
    
33.                 }
    
34.                 previosVector = currentVector;
    
35. 
    
36.                 if (j == start) break;
    
37.         }
    
38.         if (count)
    
39.                 return (true); // point is included to the polygon
    
40.         else
    
41.                 return (false); // point is not included to the polygon
    
42. }
    

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小树袋熊

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amw3

能不能說一下原理呀!看不明白