# normal of plane

hello ,i have to construct 3 surface planes ,and i need to construct thier normals....i need to know how to get the normale vector of more surface(plane ,or not) (automatically )?and how to calculate the angle between these 2 normals vectors of each surface.

if any one can get me some suggestion to this problem
sama

check the post of Chris Oke here

Regards,

thanks for help.
also ,i need to make the normal of more faces adjacent succesively:
//code (taked from marco code)
TColgp_Array2OfPnt array1(1,2,1,2);
array2.SetValue(1,1,gp_Pnt P1);
array2.SetValue(1,2,gp_Pnt P2);
array2.SetValue(1,3,gp_Pnt P3);
array2.SetValue(1,4,gp_Pnt P4);

TColgp_Array2OfPnt array2(1,2,1,2);
array2.SetValue(1,1,gp_Pnt P5);
array2.SetValue(1,2,gp_Pnt P6);
array2.SetValue(1,3,gp_Pnt P7);
array2.SetValue(1,4,gp_Pnt P8);

Handle (Geom_BezierSurface) BezierSurf1 = new Geom_BezierSurface(array1);
TopoDS_Face F1 = BRepBuilderAPI_MakeFace(BezierSurf1);
Handle(AIS_Shape) anAISShape1=new AIS_Shape(F1);
myAISContext->Display(anAISShape1, Standard_False);

Handle (Geom_BezierSurface) BezierSurf2 = new Geom_BezierSurface(array2);
TopoDS_Face F2 = BRepBuilderAPI_MakeFace(BezierSurf2);
Handle(AIS_Shape) anAISShape2=new AIS_Shape(F2);
myAISContext->Display(anAISShape2, Standard_False);

// the question is how to make automaticaly the normal of face (F1,F2...)//it's possible to put the Faces in tab[j]; and to get the normal without repeating the code.
//
GProp_GProps system;
BRepGProp::SurfaceProperties(F1, system);// ?? how to get the something for the face F2 without repeating these lines.//
gp_Pnt centro = system.CentreOfMass();
Standard_Real u, v;
//
gp_Dir normale;

BRepLProp_SLProps props(adaptorSurface, u, v, 2, Precision::Confusion());
normale = props.Normal();
myAISContext->Display( new AIS_Point( new Geom_CartesianPoint( centro) ) );
myAISContext->Display( new AIS_Line( new Geom_Line( centro, normale )) );

if you can explain me by code.
best regards

i am waiting for your suggestion!!! ,; maybe i have to use .add Methodes???
regards

Attachments:

if any ideas???
regards