SbViewVolume(3IV)
SbViewVolume (SbViewVol) - 3D viewing volume class
Showing IRIX 6.5.30 (default release). Added in IRIX 6.5.22.
NAME SbViewVolume (SbViewVol) - 3D viewing volume class INHERITS FROM SbViewVolume SYNOPSIS #include <Inventor_c/SbLinear.h> typedef SbViewVolume SbViewVol enum SbViewVolumeProjectionType { SB_VIEW_VOL_ORTHOGRAPHIC Orthographic projection SB_VIEW_VOL_PERSPECTIVE Perspective projection } Functions from class SbViewVolume: SbViewVolume * SbViewVolCreate() void SbViewVolDelete(SbViewVol *this) void SbViewVolGetMxs(const SbViewVol *this, SbMatrix *affine, SbMatrix *proj) SbMatrix SbViewVolGetMx(const SbViewVol *this) SbMatrix SbViewVolGetBoxMx(const SbViewVol *this) void SbViewVolProjPtToLine(const SbViewVol *this, const SbVec2f *pt, SbLine *line) void SbViewVolProjPtToLinePts(const SbViewVol *this, const SbVec2f *pt, SbVec3f *line0, SbVec3f *line1) void SbViewVolProjToScreen(const SbViewVol *this, const SbVec3f *src, SbVec3f *dst) SbPlane SbViewVolGetPln(const SbViewVol *this, float distFromEye) SbVec3f SbViewVolGetSightPt(const SbViewVol *this, float distFromEye) SbVec3f SbViewVolGetPlnPt(const SbViewVol *this, float distFromEye, const SbVec2f *normPoint) SbRotation SbViewVolGetAlignRot(const SbViewVol *this, SbBool rightAngleOnly = FALSE) float SbViewVolGetWorldToScreenScale(const SbViewVol *this, const SbVec3f *worldCenter, float normRadius) SbVec2f SbViewVolProjBox(const SbViewVol *this, const SbBox3f *box) SbViewVolume SbViewVolNarrow2d(const SbViewVol *this, float left, float bottom, float right, float top) SbViewVolume SbViewVolNarrow3d(const SbViewVol *this, const SbBox3f *box) void SbViewVolOrtho(SbViewVol *this, float left, float right, float bottom, float top, float near, float far) void SbViewVolPersp(SbViewVol *this, float fovy, float aspect, float near, float far) void SbViewVolRotCam(SbViewVol *this, const SbRotation *q) void SbViewVolXlateCam(SbViewVol *this, const SbVec3f *v) SbVec3f SbViewVolZVec(const SbViewVol *this) SbViewVolume SbViewVolZNarrow(const SbViewVol *this, float near, float far) void SbViewVolScale(SbViewVol *this, float factor) void SbViewVolScaleWidth(SbViewVol *this, float ratio) void SbViewVolScaleHeight(SbViewVol *this, float ratio) ProjectionType SbViewVolGetProjType(const SbViewVol *this) const SbVec3f * SbViewVolGetProjPt(const SbViewVol *this) const SbVec3f * SbViewVolGetProjDir(const SbViewVol *this) float SbViewVolGetNearDist(const SbViewVol *this) float SbViewVolGetWidth(const SbViewVol *this) float SbViewVolGetHeight(const SbViewVol *this) float SbViewVolGetDepth(const SbViewVol *this) DESCRIPTION Class used to represent a 3D viewing volume. This class is used to represent viewing frusta and picking volumes. For perspective projection, the view volume is a frustum. For orthographic (parallel) projection, the view volume is a rectangular prism. FUNCTIONS SbViewVolume * SbViewVolCreate() void SbViewVolDelete(SbViewVol *this) Constructor and destructor. void SbViewVolGetMxs(const SbViewVol *this, SbMatrix *affine, SbMatrix *proj) Returns two matrices corresponding to the view volume. The first is a viewing matrix, which is guaranteed to be an affine transformation. The second is suitable for use as a projection matrix in OpenGL. SbMatrix SbViewVolGetMx(const SbViewVol *this) Like the method above, but returns the affine and projection parts together in one matrix (i.e., affine.multRight( proj ) ). SbMatrix SbViewVolGetBoxMx(const SbViewVol *this) Returns a matrix that transforms the view volume into camera space: it translates the view volume so the viewpoint is at the origin, and rotates it so the view direction is along the negative z axis. void SbViewVolProjPtToLine(const SbViewVol *this, const SbVec2f *pt, SbLine *line) void SbViewVolProjPtToLinePts(const SbViewVol *this, const SbVec2f *pt, SbVec3f *line0, SbVec3f *line1) Maps a 2D point (in 0 <= x,y <= 1) to a 3D line. void SbViewVolProjToScreen(const SbViewVol *this, const SbVec3f *src, SbVec3f *dst) Maps the 3D point in world coordinates to a 2D point in normalized screen coordinates (0 <= x,y,z <= 1). The z-screen coordinate represents the homogenized z coordinate which goes (nonlinearly) from 0 at the near clipping plane to 1 at the far clipping plane. SbPlane SbViewVolGetPln(const SbViewVol *this, float distFromEye) Returns a plane parallel to the near (or far) plane of the view volume at a given distance from the projection point (eye). SbVec3f SbViewVolGetSightPt(const SbViewVol *this, float distFromEye) Returns the point along the line of sight at the given distance from the projection point (eye). SbVec3f SbViewVolGetPlnPt(const SbViewVol *this, float distFromEye, const SbVec2f *normPoint) Returns the projection of a given point in normalized screen coordinates (see projectToScreen()) onto the plane parallel to the near plane that is at distFromEye units from the eye. SbRotation SbViewVolGetAlignRot(const SbViewVol *this, SbBool rightAngleOnly = FALSE) Returns a rotation that would align a viewed object so that its positive x-axis (of its object space) is to the right in the view and its positive y-axis is up. If rightAngleOnly is TRUE, it will come as close as it can to this goal by using only 90 degree rotations. float SbViewVolGetWorldToScreenScale(const SbViewVol *this, const SbVec3f *worldCenter, float normRadius) Returns a scale factor that would scale a unit sphere centered at worldCenter so that it would appear to have the given radius in normalized screen coordinates when projected onto the near plane. SbVec2f SbViewVolProjBox(const SbViewVol *this, const SbBox3f *box) Projects the given 3D bounding box onto the near plane and returns the size (in normalized screen coordinates) of the rectangular region that encloses it. SbViewVolume SbViewVolNarrow2d(const SbViewVol *this, float left, float bottom, float right, float top) Given a view volume, narrows the view to the given sub-rectangle of the near plane. The coordinates of the rectangle are between 0 and 1, where (0,0) is the lower-left corner of the near plane and (1,1) is the upper-right corner. SbViewVolume SbViewVolNarrow3d(const SbViewVol *this, const SbBox3f *box) Narrows a view volume by the given box. The box must lie inside the unit cube, and the view will be shrunk according to the size of the box. void SbViewVolOrtho(SbViewVol *this, float left, float right, float bottom, float top, float near, float far) Sets up an orthographic view volume with the given sides. The parameters are the same as for the OpenGL glOrtho() routine. void SbViewVolPersp(SbViewVol *this, float fovy, float aspect, float near, float far) Sets up a perspective view volume with the given field of view and aspect ratio. The parameters are the same as for the OpenGL gluPerspective() routine, except that the field of view angle is specified in radians. void SbViewVolRotCam(SbViewVol *this, const SbRotation *q) Rotate the camera view direction. Note that this accomplishes the reverse of doing an OpenGL glRotate() command after defining a camera, which rotates the scene viewed by the camera. void SbViewVolXlateCam(SbViewVol *this, const SbVec3f *v) Translate the camera viewpoint. Note that this accomplishes the reverse of doing an OpenGL glTranslate() command after defining a camera, which translates the scene viewed by the camera. SbVec3f SbViewVolZVec(const SbViewVol *this) Returns the positive z axis in eye space. In this coordinate system, the z value of the near plane should be GREATER than the z value of the far plane. SbViewVolume SbViewVolZNarrow(const SbViewVol *this, float near, float far) Returns a narrowed view volume which contains as tightly as possible the given interval on the z axis (in eye space). The returned view volume will never be larger than the current volume, however. near and far are given in terms of zVector(): this means that near > far must hold. void SbViewVolScale(SbViewVol *this, float factor) Scales width and height of view volume by given factor. void SbViewVolScaleWidth(SbViewVol *this, float ratio) void SbViewVolScaleHeight(SbViewVol *this, float ratio) Scales view volume to be the given ratio of its current width or height, leaving the resulting view volume centered about the same point (in the near plane) as the current one. ProjectionType SbViewVolGetProjType(const SbViewVol *this) const SbVec3f * SbViewVolGetProjPt(const SbViewVol *this) const SbVec3f * SbViewVolGetProjDir(const SbViewVol *this) Returns projection information. float SbViewVolGetNearDist(const SbViewVol *this) Returns distance from projection point to near plane. float SbViewVolGetWidth(const SbViewVol *this) float SbViewVolGetHeight(const SbViewVol *this) float SbViewVolGetDepth(const SbViewVol *this) Returns bounds of viewing frustum. FILE FORMAT/DEFAULTS ViewVolume { } SEE ALSO SbVec3f, SbVec2f, SbBox3f, SbMatrix, SbRotation