I'm a newbie with OCC. I want to ask you 1 question: How can I extract coordinates of all the vertices of a slot from a STEP file and input the result to a text file with name separately for each vertex (like vertex1 (3; 4; 5), vertex2 (1; 2; 3)?
I hope to receive your answers soon.
Tuan
Discussion
4 archived replies
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01Commenter-1
Ciao
//! all includes have been intentionally omitted
//! assuming you .step file is FILENAME
//! coords are written onto stdoutput
//! BRepTool::Pnt(const TopoDS_Vertex) gets access to the point coords
STEPControl_Reader aReader;
IFSelect_ReturnStatus stat = aReader.ReadFile(FILENAME);
if(stat!=IFSelect_RetDone) exit(1);
aReader.TransferRoots();
const TopoDS_Shape &aShape = aReader.OneShape();
TopTools_IndexedMapOfShape vMap;
TopExp::MapShapes(aShape,TopAbs_VERTEX,vMap);
for(int n=1; n<=vMap.Extent(); n++)
{
const TopoDS_Vertex &aVertex = TopoDS::Vertex(vMap.FindKey(n));
const gp_Pnt &P = BRep_Tool::Pnt(aVertex);
int index = vMap.FindIndex(aVertex);
printf("Vertex index: %d Coords(%f, %f, %f)\n",index,P.X(),P.Y(),P.Z());
}
Commenter-1
02Author
Hello Giovanni,
Thank you for your reply. It worked.
Can you help me with a problem about the normal vector?
I extracted the normal vector of all planes of Slot. But do you know how to calculate the cross and dot product between 2 normal vectors?
Tuan
03Commenter-1
Ciao
gp_Dir identifies a unit vector in space. Example for a dot product:
gp_Dir aDirection1;
gp_Dir aDirection2;
double val = aDirection1.Dot(aDirection2); //! scalar procuct
For a the vectorial product use the method gp_Dir::cross.
Several methods are available. See the documentation of package gp for further details.
Commenter-1
04Author
Hello,
Thank you for your answer.
Do you know how to choose exactly the normal vector of 3 planes creating the slot (see in the step file)?
