/* * * SOP Sphere Example - currently this only gives a Poly Representation and does not fuse the polar ends properly * but does display poles correctly. WIP - emphasis is on learning the gdp. * * Deborah R. Fowler * Dec 15, 2012 * * From the odforce forums - taking the idea from * http://forums.odforce.net/index.php?/topic/13850-drawing-geometry-in-houdini/ * I have filled in the blanks on the idea of drawing a sphere etc. at HDK level * For example, the "do some math ... part is based * on the parametric equation for a sphere wiki entry http://en.wikipedia.org/wiki/Sphere * */ #include #include #include #include #include #include #include #include #include #include #include #include "sopSphereExample.h" using namespace HDK_Sample; // This is standard declaration for the SOP_Node to add it into the Nodes UI panel void newSopOperator(OP_OperatorTable *table) { table->addOperator( new OP_Operator("SphereExample", // Node Name - Default Name "SphereExampleHDK", // UI name sopSphereExample::myConstructor, // How to build the SOP sopSphereExample::myTemplateList, // My UI parameters 0, // Min # of I/O sources 0, // Max # of I/O sources sopSphereExample::myVariables, // Local variables OP_FLAG_GENERATOR) // Flag it as generator ); }; // This is the parameters for the UI and input variables for the Node... static PRM_Name variable_name("radius", "Radius"); static PRM_Default variable_defaults(1); static PRM_Range variable_range(PRM_RANGE_RESTRICTED, 0, PRM_RANGE_UI, 100); static PRM_Name res_name("res", "Res"); static PRM_Default res_defaults(16); static PRM_Range res_range(PRM_RANGE_RESTRICTED, 16, PRM_RANGE_UI, 64); PRM_Template sopSphereExample::myTemplateList[] = { PRM_Template( PRM_XYZ, 3, &PRMcenterName ), PRM_Template( PRM_FLT, 1, &variable_name, &variable_defaults, 0, &variable_range ), PRM_Template( PRM_INT, 1, &res_name, &res_defaults, 0, &res_range ), PRM_Template() }; // Here's how we parse out internal variables enum { VAR_PT, VAR_NPT }; // $PT $NPT CH_LocalVariable sopSphereExample::myVariables[] = { { "PT", VAR_PT, 0 }, // The table provides a mapping { "NPT", VAR_NPT, 0 }, // from text string to integer token { 0, 0, 0 }, }; float sopSphereExample::getVariableValue( int index, int thread ) { if (myCurrPoint < 0) return 0; switch (index) { case VAR_PT: return myCurrPoint; case VAR_NPT: return myTotalPoints; } return SOP_Node::getVariableValue(index, thread); }; // These are the constructors... OP_Node * sopSphereExample::myConstructor(OP_Network *net, const char *name, OP_Operator *op) { return new sopSphereExample(net, name, op); }; sopSphereExample::sopSphereExample(OP_Network *net, const char *name, OP_Operator *op) : SOP_Node(net, name, op) { }; sopSphereExample::~sopSphereExample() { }; unsigned sopSphereExample::disableParms() { return 0; }; // This is what COOKs the SOP OP_ERROR sopSphereExample::cookMySop(OP_Context &context) { // First grab the frame time and variables form the UI double now; UT_Interrupt *boss; // Create an array that will store the points references const int MAXTotalPoints = 64; GEO_Point *sphere_points[MAXTotalPoints * MAXTotalPoints]; int number_faces = myTotalPoints * myTotalPoints - 1; now = context.getTime(); int res = evalInt("res",0,now); myTotalPoints = res; number_faces = res * res - 1; // What is the current values of center fpreal tx = evalFloat("t",0,now); fpreal ty = evalFloat("t",1,now); fpreal tz = evalFloat("t",2,now); fpreal r = evalFloat("radius",0,now); cout << "Test Message: Version 1 \n"; cout << res; cout.flush(); // not required on Windows, but usually needed on Linux gdp->clearAndDestroy(); // Check to see that there hasn't been a critical error in cooking the SOP. if ( error() < UT_ERROR_ABORT ) { boss = UTgetInterrupt(); if ( boss->opStart("Cooking SOP...") ) { // Adding points to the detail and storing their references in *sphere_points for( int pc = 0; pc < myTotalPoints * myTotalPoints; pc++ ) { //Creating point in the details sphere_points[pc] = gdp->appendPoint(); } // Once you have that you need to calculate your points values. (This depends on what you are trying to draw) // In a sphere it is as follows const float PI = 3.141592653589; float angle = (2.0 * PI) / (myTotalPoints); // from 0 to 2 pi float otherangle = PI / (myTotalPoints-1); // from 0 to pi float x = 0; float y = 0; float z = 0; for ( int i = 0; i < myTotalPoints; i++ ) { for( int j = 0; j < myTotalPoints; j++ ) { x = tx + r * cos(angle * i) * sin(otherangle * j); y = ty + r * sin(angle * i) * sin(otherangle * j); z = tz + r * cos(otherangle * j); //Vector to store our result UT_Vector4 P; //Setting vector values P.assign(x,y,z,1); //Setting the position of the points that were appended above sphere_points[i*myTotalPoints+j]->setPos(P); } } // Print the points for debugging purposes /* for( int i = 0; i < myTotalPoints * myTotalPoints; i++ ) { cout << "point number " << i << " = " << sphere_points[i]->getPos() << endl; } */ // So far this will draw only points (the GEO_Point is now in gdp // The set of points are defined for the sphere, but to draw the surfaces, you need to create a primitive GEO_PrimPoly* prim_poly_ptr; int p1_index = 0; int p2_index = myTotalPoints; int p3_index = myTotalPoints+1; int p4_index = 1; // Drawing surfaces for( int fn = 0; fn < number_faces; fn++ ) { //Creating a polygon and setting its size to zero as is shown in the api example //This polygon has no vertices yet prim_poly_ptr = dynamic_cast (gdp->appendPrimitive(GEO_PRIMPOLY)); prim_poly_ptr->setSize(0); //Now you append vertices to that primitive polygon and pass them a reference to the point that they correspond from our sphere point list //In this example I draw my sphere as quads since it was easier to procedural map the points to an index // check if we are at the poles, otherwise go ahead if (p1_index % myTotalPoints == 0) { //Point 1 prim_poly_ptr->appendVertex(sphere_points[0]); //Point 3; prim_poly_ptr->appendVertex(sphere_points[p3_index]); //Point 4; prim_poly_ptr->appendVertex(sphere_points[p4_index]); } else { if ((p3_index + 1) % myTotalPoints == 0) { //Point 1 prim_poly_ptr->appendVertex(sphere_points[p1_index]); //Point 2 prim_poly_ptr->appendVertex(sphere_points[p2_index]); //Point 3 prim_poly_ptr->appendVertex(sphere_points[ myTotalPoints-1]); } else { //Point 1 prim_poly_ptr->appendVertex(sphere_points[p1_index]); //Point 2 prim_poly_ptr->appendVertex(sphere_points[p2_index]); //Point 3; prim_poly_ptr->appendVertex(sphere_points[p3_index]); //Point 4; prim_poly_ptr->appendVertex(sphere_points[p4_index]); } } //Closing the primitive to make it a polygon instead of a poly line prim_poly_ptr->close(); p1_index += 1; p2_index += 1; p3_index += 1; p4_index += 1; if (p1_index >= myTotalPoints * myTotalPoints ) p1_index = 0; if (p2_index >= myTotalPoints * myTotalPoints) p2_index = 0; if (p3_index >= myTotalPoints * myTotalPoints) p3_index = 0; if (p4_index >= myTotalPoints * myTotalPoints) p4_index = 1; } } boss->opEnd(); }; gdp->notifyCache(GU_CACHE_ALL); myCurrPoint = -1; return error(); };