Solids of extrusion.

 

Let's create a solid of extrusion with a circular hole. An unclosed spline will be the extruded contour.

 

This code creates a spline:

 

SG_POINT tmpPnt;

 SG_SPLINE* spl2 = SG_SPLINE::Create();

 int fl=0;

 for (double i=0.0;i<2.0*3.14159265;i+=0.13)

 {

         tmpPnt.x = ((double)(fl%3+2))*cos(i);

         tmpPnt.y = ((double)(fl%3+2))*sin(i);

         tmpPnt.z = 0.0;

         spl2->AddKnot(tmpPnt,fl);

         fl++;

 }

 spl2->Close();

 sgCSpline* spl2_obj = sgCreateSpline(*spl2);

 SG_SPLINE::Delete(spl2);

 sgGetScene()->AttachObject(spl2_obj);

 spl2_obj->SetAttribute(SG_OA_COLOR,12);

 spl2_obj->SetAttribute(SG_OA_LINE_THICKNESS, 2);

 

The hole will have the form of the circle with 1.6 radius:

 

SG_CIRCLE   cirGeo;

 SG_POINT    cirC = {0.0, 0.0, 0.0};

 SG_VECTOR    cirNor = {0.0, 0.0, 1.0};

 cirGeo.FromCenterRadiusNormal(cirC,1.6, cirNor);

 sgC2DObject*  cir = sgCreateCircle(cirGeo);

 sgGetScene()->AttachObject(cir);

 cir->SetAttribute(SG_OA_COLOR,12);

 cir->SetAttribute(SG_OA_LINE_THICKNESS, 2);

 

Let's extrude along the (1, -2, 5) vector:

 

 SG_VECTOR extVec = {1,-2,5};

 

 sgC3DObject* exO = (sgC3DObject*)sgKinematic::Extrude((const sgC2DObject&)(*spl2_obj),

         (const sgC2DObject**)(&cir),1,extVec,true);

 

 sgGetScene()->AttachObject(exO);

 exO->SetAttribute(SG_OA_COLOR,30);

 

Then we'll move the obtained solid:

 

  SG_VECTOR transV1 = {-7,0,0};

 exO->InitTempMatrix()->Translate(transV1);

 exO->ApplyTempMatrix();

 exO->DestroyTempMatrix();

 

See also:

sgKinematic::Extrude  

sgCSpline   sgCSpline::Create SG_SPLINE

sgGetScene sgCScene::AttachObject   sgCObject::SetAttribute

 

Illustration:

kin_ex_b