Examples > Surfaces > Spline solid from clips

Spline solid from clips.

Let's create a smooth solid from three clips - splines. Two of the splines are identical but moved and turned one about another.

This code creates two clips:

SG_POINT tmpPnt;

SG_SPLINE* spl1 = SG_SPLINE::Create();

int fl=0;

for (double i=0.0;i<2.0*3.14159265;i+=0.4)

{

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

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

tmpPnt.z = 0.0;

spl1->AddKnot(tmpPnt,fl);

fl++;

}

spl1->Close();

sgCSpline* spl1_obj = sgCreateSpline(*spl1);

SG_SPLINE::Delete(spl1);

sgGetScene()->AttachObject(spl1_obj);

spl1_obj->SetAttribute(SG_OA_COLOR,12);

spl1_obj->SetAttribute(SG_OA_LINE_THICKNESS, 2);

SG_SPLINE* spl2 = SG_SPLINE::Create();

tmpPnt.x = 0.0; tmpPnt.y = -0.9; tmpPnt.z = 2.0;

spl2->AddKnot(tmpPnt,0);

tmpPnt.x = 1.4; tmpPnt.y = 0.9; tmpPnt.z = 2.0;

spl2->AddKnot(tmpPnt,1);

tmpPnt.x = -1.6; tmpPnt.y = 0.6; tmpPnt.z = 2.0;

spl2->AddKnot(tmpPnt,2);

tmpPnt.x = -1.2; tmpPnt.y = -1.6; tmpPnt.z = 2.0;

spl2->AddKnot(tmpPnt,3);

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);

sgGetScene()->AttachObject(spl1_obj);

sgGetScene()->AttachObject(spl2_obj);

The third clip will be the copy of the first one but moved and turned:

sgC2DObject* ooo[3];

ooo[1] = spl1_obj;

ooo[0] = spl2_obj;

ooo[2] = (sgC2DObject*)spl2_obj->Clone();

sgGetScene()->AttachObject(ooo[2]);

SG_POINT axeP = {0.0, 0.0, 0.0};

SG_VECTOR axeD = {0.0, 0.0, 1.0};

axeD.z = 0.0; axeD.x = 1.0;

ooo[2]->InitTempMatrix()->Rotate(axeP,axeD, 3.14159265/4.0);

SG_VECTOR trV = {-1.0, 1.0, -3.0};

ooo[2]->GetTempMatrix()->Translate(trV);

ooo[2]->ApplyTempMatrix();

ooo[2]->DestroyTempMatrix();

This code creates the solid itself:

double ppp[3];

ppp[0] = 0.1;

ppp[1] = 0.0;

ppp[2] = 0.2;

sgCObject* lsf = sgSurfaces::SplineSurfaceFromSections((const sgC2DObject**)(&ooo[0]),

ppp,3,true);

sgGetScene()->AttachObject(lsf);

lsf->SetAttribute(SG_OA_COLOR,23);

Then let's move the obtained solid:

SG_VECTOR transV1 = {8,0,0};

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

lsf->ApplyTempMatrix();

lsf->DestroyTempMatrix();