Creating a solid from a set of “water-tight” surfaces

By Balaji Ramamoorthy

A collection of surfaces that together form a closed volume and which do not have gaps, overlaps, such surfaces can be used to create a solid. Here is a sample code to do this using the “createSculptedSolid” method of the “AcDb3dSolid” class.

// surfaceOids : 
// A collection of the objectId of the surfaces that 
// form the bounds of the solid
 
Acad::ErrorStatus es;
 
AcDb3dSolid *pSolid = new AcDb3dSolid();
pSolid->setDatabaseDefaults();
 
AcArray surfacesArray;
AcGeIntArray limits;
AcDbEntity *pSurfaceEnt;
 
for(int surfCnt = 0;
        surfCnt < surfaceOids.size(); surfCnt++)
{
    es = acdbOpenAcDbEntity(
                pSurfaceEnt, surfaceOids[surfCnt],
                AcDb::kForRead);
 
    if ( es == Acad::eOk &&
         pSurfaceEnt->isKindOf(AcDbSurface::desc()))
    {
        surfacesArray.append(pSurfaceEnt);
    }
}
 
es = pSolid->createSculptedSolid(surfacesArray, limits);
if(es == Acad::eOk)
{
    AcDbObjectId solidOid = AcDbObjectId::kNull;
    Add2Db(pSolid, solidOid);
 
    // To show the newly created solid away 
    // from the surfaces, we transform it..
    AcDbEntity *pSolidEnt;
    es = acdbOpenAcDbEntity(
            pSolidEnt, solidOid, AcDb::kForWrite);
    if  (es == Acad::eOk &&
            pSolidEnt->isKindOf(AcDb3dSolid::desc()))
    {
        AcGeVector3d vec(15.0, 15.0, 0.0);
        AcGeMatrix3d transform =
                    transform.setToTranslation(vec);
        es = pSolidEnt->transformBy(transform);
        pSolidEnt->close();
        acutPrintf(ACRX_T(
                    "Solid3d created from surfaces !"));
    }
    else
    {
        acutPrintf(ACRX_T("Solid3d creation failed !"));
    }
}
else
{
    acutPrintf(ACRX_T("Solid3d creation failed !"));
    delete pSolid;
}
 
// Close the surfaces
int surfCnt = 0;
for(; surfCnt < surfacesArray.length(); surfCnt++)
{
    pSurfaceEnt = surfacesArray[surfCnt];
    pSurfaceEnt->close();
}