Graphics Programming in 3D - Essentials of Interactive Computer Graphics - page 462

CModel::CModel() : m _ root _ node( L"root node" ) {
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Source file. Model.cpp
file in the Model folder of
the D3D _ SimpleHierarchy
project.

// Base node for user interaction

UWB _ SceneNode * pBaseNode = new UWB _ SceneNode(...);
// Node for xform Cylinder Mesh
UWB _ SceneNode * pCylinderNode = new UWB _ SceneNode(...);
// Top node for user interaction
UWB _ SceneNode * pTopNode = new UWB _ SceneNode(...);
// Node for xform Cone Mesh
UWB _ SceneNode * pConeNode = new UWB _ SceneNode(...);
.

A:

B: pBaseNode->InsertChildNode(pCylinderNode); // Cylinder is child of Base

pBaseNode->InsertChildNode(pTopNode); // Top is child of Base

pTopNode->InsertChildNode(pConeNode); // Cone is child of Top

m _ root _ node.InsertChildNode(pBaseNode); // base is root of hierarchy

.

pMesh = new UWBD3D _ PrimitiveMesh(L"cylinder.x"); // Cylinder mesh primitive
.
xf1.UpdateRotationXByDegree(90);

C:

// X rotation of 90 degrees

xf1.SetScale( vec3 (3.0f/2.0f, 3.0f/2.0f, 2.0f)); // Scale to right radius/height

xf1.SetTranslation( vec3 (0.0f, 3.0f, 0.0f)); // ensure one end at origin

pCylinderNode->SetXformInfo(xf1); // xform mesh to component location

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pMesh = new UWBD3D _ PrimitiveMesh(L"OpenCone.x"); // Cone mesh primitive
.
xf2.UpdateRotationXByDegree(-90);

D:

// X rotation of -90 degrees

xf2.SetScale( vec3 (2.0f, 2.0f, 2.0f/3.0f)); // scale to right radius/height

xf2.SetTranslation( vec3 (0.0f, 7.0f, 0.0f)); // ensure tip at top of cylinder

pConeNode->SetXformInfo(xf2); // xform mesh to component position

.

E:

m2.SetPivot( vec3 (0.0f, 6.0f, 0.0f)); // pivoted at top of cylinder
pTopNode->SetXformInfo(m2); // top node pivoted at top of cylinder

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Listing 16.21. Building a simple hierarchy.