HUtilityGeometryCreation

Functions

bool	GeneratePointOnCircle
bool	GeneratePointsOnCircle
bool	GeneratePointsOnCircularArc
HC_KEY	CreateWireframeCircleWithEllipse
HC_KEY	CreateSphere
HC_KEY	CreateSphere
HC_KEY	CreateCone
HC_KEY	CreateCylinder
HC_KEY	CreateCuboid
void	SetupModellingMatrix
HC_KEY	CreateCuttingPlane
void	SetCuttingPlaneVisibilityForAll
void	AdjustCuttingPlaneRendering
void	AdjustSection
void	CreateThreeSidedSection
void	CreateTwoSidedSection
void	CreateSlice
HC_KEY	CreateShellWithFaceSpecificVertexAttributes
HC_KEY	CreateShellWithFaceSpecificVertexAttributes
HC_KEY	GenerateFEAShell
HC_KEY	CreateSmoothedShell
bool	ComputeFIndexDemoData
HC_KEY	CreateBoolean
HC_KEY	CreateShellFromRotationalSweep
HC_KEY	CreateShellFromPathSweep

Detailed Description

class HUtilityGeometryCreation

This class provides utility functions for creating construction geometry as well as simple primitives (spheres, cones, cylinders, etc…)

Public Static Functions

static bool GeneratePointOnCircle(HPoint *point, HPoint const &center, float radius, int axis, float angle, bool convert = true)

GeneratePointOnCircle generates a single point along a circle based on a centerpoint, a radius, and an angle.

Parameters

• point – A pointer to an HPoint object which denotes the generated point.

• center – The center point of the circle.

• radius – The length of the radius of the circle.

• axis – XY, XZ, or YZ. This defines the view plane in which the circle will be drawn, as well as the axis of rotation for the angular offset of the point. XY defines the z-axis, XZ defines the y-axis, and YZ defines the x-axis.

• angle – Radians measured from 0 about the axis defined by the ‘axis’ parameter.

• convert – Boolean indicating whether to convert the point from viewpoint space to world space. The default is true.

Returns

A boolean value indicating success or failure

static bool GeneratePointsOnCircle(HPoint points[], HPoint const &center, float radius, int axis, int numpoints, bool convert = true)

GeneratePointsOnCircle generates multiple points along a circle based a center point and a radius. The desired number of points must be specified, and must be equal to the size of the points array if the size of that array has been defined. Note that the basic work in this function is accomplished by repeated calls to GeneratePointOnCircle.

Parameters

• points – A pointer to an array of HPoint objects which denote the generated points.

• center – The center point of the circle.

• radius – The radius of the circle.

• axis – XY, XZ, or YZ. This defines the view plane in which the circle will be drawn.

• numpoints – The desired number of points in the circle.

• convert – Pass true if you want HOOPS to convert the point from viewpoint space to world space or false if you don’t. The default is true.

Returns

True if the operation was a success or false if it failed.

static bool GeneratePointsOnCircularArc(HPoint points[], HPoint const &center, float radius, int axis, int numpoints, bool convert, float start_angle, float end_angle)

GeneratePointsOnCircularArc generates multiple points along an arc based a center point and a radius. The desired number of points must be specified, and must be equal to the size of the points array if the size of that array has been defined. Note that the basic work in this function is accomplished by repeated calls to GeneratePointOnCircle.

Parameters

• points – A pointer to an array of HPoint objects which denote the generated points.

• center – The center point of the arc.

• radius – The radius of the arc.

• axis – XY, XZ, or YZ. This defines the view plane in which the arc will be drawn.

• numpoints – The desired number of points in the arc.

• convert – Pass true if you want HOOPS to convert the point from viewpoint space to world space or false if you don’t. The default is true.

• start_angle – In radians. Angle about the arc axis (in anticlockwise direction) from where the arc starts

• end_angle – In radians. Angle about the arc axis (in anticlockwise direction) where the arc starts. For e.g. if the start_angle is 0 and end_angle is 360, the arc will form a full circle.

Returns

true if the operation was a success or false if it failed.

static HC_KEY CreateWireframeCircleWithEllipse(HPoint const &x1, HPoint const &x2, HPoint const &x3)

CreateWireframeCircleWithEllipse inserts a HOOPS/3dGS ellipse that representing a circle into the currently open segment.

Parameters

• x1 – An HPoint object which lies on the circumference of the circle.

• x2 – An HPoint object which lies on the circumference of the circle.

• x3 – An HPoint object which lies on the circumference of the circle.

Returns

The HC_KEY of the HOOPS geometry inserted if the process was successful or INVALID_KEY if it failed.

static HC_KEY CreateSphere(char const *segment, HPoint center, float radius, int num_faces)

CreateSphere inserts a HOOPS/3dGS shell representing a sphere into the specified segment.

Parameters

• segment – The segment to insert the sphere into.

• center – The coordinate representing the center of the sphere.

• radius – The length of the sphere’s radius.

• num_faces – The number of longitudinal strips that will make up the sides of the sphere.

Returns

The HC_KEY of the HOOPS geometry inserted if the process was successful or INVALID_KEY if it failed.

static HC_KEY CreateSphere(HPoint center, float radius, int numsides, HPoint axis, HPoint ref)

CreateSphere inserts a HOOPS/3dGS shell representing a sphere oriented about an arbitrary axis into a no-name subsegment of the currently open segment. The two reference axes must be orthogonal.

Parameters

• center – An HPoint object denoting the center of the sphere.

• radius – The sphere radius.

• numsides – The number of longitudinal strips that will make up the sides of the sphere.

• axis – The first reference axis used to define the orientation of the geometry.

• ref – The second reference axis used to define the orientation of the geometry.

Returns

The HC_KEY of the HOOPS geometry inserted if the process was successful or INVALID_KEY if it failed.

static HC_KEY CreateCone(HPoint center, float radius, float height, int numsides, HPoint axis, HPoint ref)

CreateCone inserts a HOOPS/3dGS shell (representing a cone oriented about an arbitrary axis) into a no-name subsegment of the currently open segment. The two reference axes must be orthogonal.

Parameters

• center – An HPoint object denoting the center of the cone.

• radius – The radius of the cone’s base.

• height – The height of the cone.

• numsides – The number of longitudinal strips that will make up the sides of the cone.

• axis – The first reference axis used to define the orientation of the geometry.

• ref – The second reference axis used to define the orientation of the geometry.

Returns

The HC_KEY of the HOOPS geometry inserted if the process was successful or INVALID_KEY if it failed.

static HC_KEY CreateCylinder(HPoint center, float radius, float height, int numsides, HPoint axis, HPoint ref)

CreateCylinder inserts a HOOPS/3dGS shell representing a cylinder oriented about an arbitrary axis into a no-name subsegment of the currently open segment. The two reference axes must be orthogonal.

Parameters

• center – An HPoint object denoting the center of the cylinder’s base.

• radius – The radius of the cylinder.

• height – The height of the cylinder.

• numsides – The number of longitudinal strips that will make up the sides of the cone.

• axis – This reference axis define the orientation of the cylinder’s base.

• ref – This reference axis define the orientation of the cylinder’s altitude.

Returns

The HC_KEY of the HOOPS geometry inserted if the process was successful or INVALID_KEY if it failed.

static HC_KEY CreateCuboid(HPoint const *max, HPoint const *min)

CreateCuboid creates a solid box spanning diagonally from min to max point. NOTE: The difference between this routine and the HUtility::InsertBox is that each face does not share any corner points. Therefore the cuboid appears flat shaded even in smooth shading mode which is realistic.

Parameters

• max – Max The coordinates that represent one end of the cuboid.

• min – Min The coordinates that lie diagonal from Max on the opposite face of the cuboid.

Returns

The HC_KEY of the HOOPS geometry inserted if the process was successful or INVALID_KEY if it failed.

static void SetupModellingMatrix(HVector axis, HVector ref, HVector side, HPoint pos)

Sets a modelling matrix based on the reference axes and position.

static HC_KEY CreateCuttingPlane(HBaseView *view, char const *segmentname = 0, bool createplane = true)

This function creates a cutting plane in the cutting plane segment of the view.

Parameters

• view – A pointer to the HBaseView object.

• segmentname – The name you want to give the cutting plane segment.

Returns

The key to the newly created cutting plane segment.

static void SetCuttingPlaneVisibilityForAll(HC_KEY startkey, char const *visibility)

Sets the given visibility for all cutting planes beginning with the given startkey.

Parameters

• startkey – The cutting plane key start key.

• visibility – The visibility setting as described in #HC_Set_Visibility().

static void AdjustCuttingPlaneRendering(HBaseView *view)

This method changes attribute settings for the cutting planes based on the current rendering mode. If render mode is HRenderHiddenLine, HRenderHiddenLineFast or HRenderBRepHiddenLine, then edges are visible and faces aren’t. If the render mode is anything else, then faces are visible and edges aren’t.

Parameters

view – A pointer to the HBaseView object.

static void AdjustSection(HBaseView *view, HC_KEY key)

This method takes a given key representing intersecting cutting planes and converts them into a cutting section that insect and affect each other.

Parameters

• view – A pointer to the HBaseView object.

• key – The key to the interesecting cutting planes.

static void CreateThreeSidedSection(HBaseView *view)

This method creates a three sided cutting section. This cutting section is more advanced form of cutting plane, where the cutting planes intersect and affect each other.

Parameters

view – A pointer to the HBaseView object.

static void CreateTwoSidedSection(HBaseView *view)

This method creates a two sided cutting section. This cutting section is more advanced form of cutting plane, where the cutting planes intersect and affect each other.

Parameters

view – A pointer to the HBaseView object.

static void CreateSlice(HBaseView *view, float relative_thickness = 0.1f)

static HC_KEY CreateShellWithFaceSpecificVertexAttributes(float points[], int face_list_length, int face_vertex_indices[], float normals[] = 0, int per_face_vertex_normal_indices[] = 0, float color_values[] = 0, int per_face_vertex_color_value_indices[] = 0, float color_findices[] = 0, int per_face_vertex_color_findex_indices[] = 0, float params[] = 0, int per_face_vertex_param_indices[] = 0, int param_number = 0, float crease_angle = 0.f)

Creates and inserts a shell with any of a variety of user options.

Parameters

• points – A pointer to an array of HPoint objects which will be used to build the shell.

• face_list_length – Total number of integers in the face_vertex_indices array.

• face_vertex_indices – Encoded description of how to connect the points to build the faces of the shell as described in #HC_Insert_Shell.

• normals – A pointer to an array of HPoint objects which will be used as normal values.

• per_face_vertex_normal_indices – Encoded description of which normals should be applied. This should be in the same format as the face_vertex_indices.

• color_values – A pointer to an array of color triples.

• per_face_vertex_color_value_indices – Encoded description of which color_values should be applied. This should be in the same format as the face_vertex_indices.

• color_findices – A pointer to an array of floating-index values.

• per_face_vertex_color_findex_indices – Encoded description of which the color_findices should be applied. This should be in the same format as the face_vertex_indices.

• params – A pointer to a two-dimensional array of floating point vertex parameters.

• per_face_vertex_param_indices – Encoded description of which of the params should be applied where. This should be in the same format as the face_vertex_indices.

• param_number – The number of parameters to be set on each vertex of the shell. This is the width of the params array.

• crease_angle – If the angle between the normals of two neighboring faces that share a vertex exceeds this value (in degrees), the vertex will be duplicated to prevent the normals from being averaged. Default is off.

static HC_KEY CreateShellWithFaceSpecificVertexAttributes(HPoint points[], int face_list_length, int face_vertex_indices[], HPoint normals[] = 0, int per_face_vertex_normal_indices[] = 0, HPoint color_values[] = 0, int per_face_vertex_color_value_indices[] = 0, float color_findices[] = 0, int per_face_vertex_color_findex_indices[] = 0, float params[] = 0, int per_face_vertex_param_indices[] = 0, int param_number = 0, float crease_angle = 0.f)

Creates and inserts a shell with any of a variety of user options.

Parameters

• points – A pointer to an array of HPoint objects which will be used to build the shell.

• face_list_length – Total number of integers in the face_vertex_indices array.

• face_vertex_indices – Encoded description of how to connect the points to build the faces of the shell as described in #HC_Insert_Shell.

• normals – A pointer to an array of HPoint objects which will be used as normal values.

• per_face_vertex_normal_indices – Encoded description of which normals should be applied. This should be in the same format as the face_vertex_indices.

• color_values – A pointer to an array of color triples.

• per_face_vertex_color_value_indices – Encoded description of which color_values should be applied. This should be in the same format as the face_vertex_indices.

• color_findices – A pointer to an array of floating-index values.

• per_face_vertex_color_findex_indices – Encoded description of which the color_findices should be applied. This should be in the same format as the face_vertex_indices.

• params – A pointer to a two-dimensional array of floating point vertex parameters.

• per_face_vertex_param_indices – Encoded description of which of the params should be applied where. This should be in the same format as the face_vertex_indices.

• param_number – The number of parameters to be set on each vertex of the shell. This is the width of the params array.

• crease_angle – If the angle between the normals of two neighboring faces that share a vertex exceeds this value (in degrees), the vertex will be duplicated to prevent the normals from being averaged. Default is off.

static HC_KEY GenerateFEAShell(HC_KEY definingShell, bool generateIsolines, char const *algorithm)

Creates a new shell in the currently open segment with its faces tesselated/colored to represent a binary interpolation of the per vertex color parameters of that shell. The original shell is not changed and should be deleted after this call in most cases.

Parameters

• definingShell – The key of shell to interpolate.

• generateIsolines – Pass true to create isolines as explicit polylines.

• algorithm – Pass bilinear or an empty string.

Returns

The key to the newly created shell.

static HC_KEY CreateSmoothedShell(int PointCount, const HPoint Points[], int FaceListLength, int const FaceList[], float creaseAngle)

Creates and inserts into the currently open segment a shell with vertices split where they would otherwise straddle a hard edge. Most usefully, this process allows Gouraud shading to display hard edges.

Parameters

• PointCount – The number of valid points in Points.

• Points – The list of vertices for building the shell.

• FaceListLength – The number of integers in FaceList.

• FaceList – Encoded description of how to connect the points to build the faces of the shell as described in #HC_Insert_Shell().

• creaseAngle – The intersection angle, in degrees, beyond which an edge is considered “hard”.

static bool ComputeFIndexDemoData(HShellVertexData *pShellVertexData, int data_cycles = 30)

This is a demonstration function that shows how a developer might use HOOPS to map analysis data to the object on which the analysis was performed. The mapped data could be results from some analysis that an application performed on a dataset (e.g., FEA thermal analysis of a crankshaft).

ComputeData looks at a given segment and for each shell in the segment computes data that is then attached to the shell vertices. In this example, the attached data are simply the y-values of the vertex normal vector. The data are then mapped into the interval [0.0, 12.0]. These values are directly used for color interpolation and color index interpolation rendering to provide color contouring.

A note on the pShellVertexData parameter: In addition to allocating it prior to the call as an HShellVertexData object, you must also allocate the array member, i.e., m_pFIndexArray, of this data structure. It must be able to hold (number of vertices + number of animation frames/cycles) floats (see MemorySizeForDemoAnimation).

Parameters

• entity_key – Key to the geometry for which one wishes to compute the demo FIndex data.

• pShellVertexData – Pointer to HShellVertexData object allocated by application.

• data_cycles – Number of steps in a complete colormap or vertex-index cycle. Must be greater than zero.

Returns

A boolean value indicating success or failure.

static HC_KEY CreateBoolean(HC_KEY target, HC_KEY tool, int bool_type)

This function performs the heavy lifting for the partviewer selection operations that compute booleans. It does handles all the set-up before and clean-up after calling HC_KCompute_Boolean_Shell. Both tool and target should be keys of manifold shells. If either is not a shell key, the return value will be INVALID_KEY.

Parameters

• target – This is the target of the boolean operation.

• tool – This is the tool for the boolean operation. In the case of subtraction, this shell will be subtracted from the target.

• bool_type – This is the type of boolean operation to be performed. Should be one of the following: BOOLEAN_TYPE_INTERSECT, BOOLEAN_TYPE_SUBTRACT, BOOLEAN_TYPE_UNION.

static HC_KEY CreateShellFromRotationalSweep(int nPoints, const HPoint profile[], float const radii[], float start_angle, float end_angle, int axis, bool const hard[], int n_sides)

CreateShellFromRotationalSweep functions creates a spun geometry (shell). It takes a profile (closed) and spins it about an axis (about X or Y or Z axis). This api is very similar to HC_Insert_Polyclyliner - which takes points on the axis and the radii of polycylinder at each of this point. The polycylinder is just a polyline spun around, here you can spin a shape. If the profile is not closed, the function will automatically close it.

Parameters

• nPoints – - no of points in the given profile.

• profile – - Array of points that defines the profile which is required to be spun. These are not the coordinates of actual profile points, but the profile points projected onto the spin axis (similar to polycylinder api)

• radii – - Array of distances of each point from axis.

• start_angle – - The starting Angle for spin, in radians.

• end_angle –

  • The end Angle for spin in radians.

• axis – - axis around which the profile will be rotated e.g. pass HUtility::XY for Z axis and so on.

• hard – - array of booleans passed with points, determines whether to keep the given edge of the profile hard. Points will be duplicated at hard edges for the lighting to appear appropriately. If null is passed, all the edges will be considered as hard edges.

• sides – - number of sides the spun geometry should have. Imagine the projection of this spun geometry along the spin axis. This is the total number of sides this polygon should have. It should be more than two. The quality and number of triangles will depend upon this parameter set of points on that edge.

static HC_KEY CreateShellFromPathSweep(int nProfilePoints, const HPoint pOuterProfilePoints[], const HPoint pInnerProfilePoints[], int nPathPoints, const HPoint pSweepPathPoints[], bool const bIsProfileClosed)

Creates a surface which is the result of sweeping of the given profile along the give path (extrusion). The profile is divided into two parts - the inner and the outer. This provides an ability to sweep hollow elements (viz. pipes). For a solid geometry, the inner profile can be null. NOTE: If the inner profile is non-null, then the number of points in the inner and outer profiles should be same

Parameters

• nProfilePoints – - number of points on outer profile

• pOuterProfilePoints – - array of profile points of outer profile

• pInnerProfilePoints – - array of profile points of inner profile (can be NULL for solid core)

• nPathPoints – - number of points in the sweep path.

• pSweepPathPoints – - array of points on path along which the profile is to be swept

• bIsProfileClosed – - If false, the first and last points of the outer and inner profiles will be joined automatically NOTE:The profile should always be placed at the start point of the path otherwise the resulting geometry will be incorrect.