Examples > Kinematic > Surfaces of revolution

Surfaces of revolution.

Let's create a surface of revolution. An unclosed spline will be the rotated contour.

This code creates a spline:

SG_POINT tmpPnt;

SG_SPLINE* spl2 = SG_SPLINE::Create();

tmpPnt.x = 1.0; tmpPnt.y = -3.0; tmpPnt.z = 0.0;

spl2->AddKnot(tmpPnt,0);

tmpPnt.x = 3.0; tmpPnt.y = -2.0; tmpPnt.z = 0.0;

spl2->AddKnot(tmpPnt,1);

tmpPnt.x = 2.0; tmpPnt.y = -1.0; tmpPnt.z = 0.0;

spl2->AddKnot(tmpPnt,2);

tmpPnt.x = 3.0; tmpPnt.y = 1.0; tmpPnt.z = 0.0;

spl2->AddKnot(tmpPnt,3);

tmpPnt.x = 2.0; tmpPnt.y = 4.0; tmpPnt.z = 0.0;

spl2->AddKnot(tmpPnt,4);

tmpPnt.x =4.0; tmpPnt.y = 5.0; tmpPnt.z = 0.0;

spl2->AddKnot(tmpPnt,5);

sgCSpline* spl2_obj = sgCreateSpline(*spl2);

sgGetScene()->AttachObject(spl2_obj);

spl2_obj->SetAttribute(SG_OA_COLOR,12);

spl2_obj->SetAttribute(SG_OA_LINE_THICKNESS, 2);

SG_SPLINE::Delete(spl2);

Let's rotate the contour around the axis lying on the (0, 0, 0) and (0, -2, 0) points. The rotation angle will be 250 degrees:

SG_POINT p1 = {0,-2,0};

SG_POINT p2 = {0,0,0};

sgC3DObject* rO = (sgC3DObject*)sgKinematic::Rotation(*spl2_obj,p1,p2,250,false);

sgGetScene()->AttachObject(rO);

rO->SetAttribute(SG_OA_COLOR,3);

Then we'll move the obtained surface:

SG_VECTOR transV1 = {-1,0,0};

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

rO->ApplyTempMatrix();

rO->DestroyTempMatrix();