# SbSphereSheetProjector Class Reference
[Projector classes (mostly for internal use)]

`#include <Inventor/projectors/SbSphereSheetProjector.h>`

Inheritance diagram for SbSphereSheetProjector:

List of all members.

## Detailed Description

The SbSphereSheetProjector class projects 2D points to 3D points on a sheet covering a spherical shape.

The following stand-alone example shows how screen space coordinates projects into 3D when mapped with an SbSphereSheetProjector. It outputs the resulting projections as an SoPointSet in a Inventor-file on stdout:

      #include <stdio.h>
      #include <Inventor/SbLinear.h>
      #include <Inventor/projectors/SbSphereSheetProjector.h>
      #include <Inventor/SoDB.h>

      int
      main(void)
      {
        SoDB::init();

        const float START = 0.0f;
        const float END = 1.0f;
        const float STEPS = 50.0f;
        const float STEPSIZE = ((END - START) / STEPS);

        SbSphere s(SbVec3f(0, 0, 0), 0.8);
        SbSphereSheetProjector ssp(s, TRUE); // last argument is orientToEye

        SbViewVolume volume;
        volume.ortho(-1, 1, -1, 1, -1, 1);
        ssp.setViewVolume(volume);

        (void)fprintf(stdout, "#Inventor V2.1 ascii\n\n"
                      "Separator {\n"
                      "  Coordinate3 {\n"
                      "    point [\n");

        for (float i=START; i <= END; i += STEPSIZE) {
          for (float j=START; j <= END; j += STEPSIZE) {
            SbVec3f v = ssp.project(SbVec2f(j, i));
            (void)fprintf(stdout, "\t%f %f %f,\n", v[0], v[1], v[2]);
          }
        }

        (void)fprintf(stdout, "      ]\n"
                      "    }\n"
                      "  DrawStyle { pointSize 2 }\n"
                      "  PointSet { }\n"
                      "}\n");

        return 0;
      }

The projections to 3D points in the resulting Inventor-file looks like this:

## Public Member Functions

| SbSphereSheetProjector (const SbBool orienttoeye=TRUE)
| SbSphereSheetProjector (const SbSphere &sph, const SbBool orienttoeye=TRUE)
virtual SbProjector * | copy (void) const
virtual SbVec3f | project (const SbVec2f &point)
virtual SbRotation | getRotation (const SbVec3f &point1, const SbVec3f &point2)

## Protected Member Functions

void | setupPlane (void)

## Protected Attributes

SbVec3f | workingProjPoint
SbVec3f | planePoint
SbVec3f | planeDir
float | planeDist
SbPlane | tolPlane

## Constructor & Destructor Documentation

SbSphereSheetProjector::SbSphereSheetProjector | ( | const SbBool | orienttoeye = TRUE | ) |

| Constructor. Uses default sphere defintion, see SbSphereProjector::SbSphereProjector(). orienttoeye decides whether or not the sheet should always be oriented towards the viewer.

SbSphereSheetProjector::SbSphereSheetProjector | ( | const SbSphere & | sph,
|  | const SbBool | orienttoeye = TRUE
| ) |

| Constructor with explicit definition of projection sphere.

## Member Function Documentation

SbProjector * SbSphereSheetProjector::copy | ( | void |  | ) | const`[virtual]`

Construct and return a copy of this projector. The caller is responsible for destructing the new instance.

Note that if the Coin library has been built as a DLL under Microsoft Windows and you use this method from application code, you must make sure that both the Coin DLL and the application executable is using the same instance of a C Run-Time (CRT) library. Otherwise, you will get memory heap corruption upon deallocating the returned instances, eventually leading to mysterious crashes.

Implements SbProjector.

SbVec3f SbSphereSheetProjector::project | ( | const SbVec2f & | point | ) | `[virtual]`

| Project the 2D point from normalized viewport coordinates to a 3D point. The mapping will be done in accordance with the type of the projector. Implements SbProjector.

SbRotation SbSphereSheetProjector::getRotation | ( | const SbVec3f & | point1,
|  | const SbVec3f & | point2
| ) | `[virtual]`

| Returns rotation on the projection surface which re-orients point1 to point2. Implements SbSphereProjector.

void SbSphereSheetProjector::setupPlane | ( | void |  | ) | `[protected]`

| Recalculates projection surface settings after changes to the parameters.

## Member Data Documentation

SbSphereSheetProjector::workingProjPoint `[protected]`

| Last projected point, in the working space coordinate system.

SbSphereSheetProjector::planePoint `[protected]`

| Position of the center of the sphere in the plane of the hyberbolic sheet.

SbSphereSheetProjector::planeDir `[protected]`

| Normal vector of the plane defining the orientation of the sheet.

SbSphereSheetProjector::planeDist `[protected]`

| This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

SbSphereSheetProjector::tolPlane `[protected]`

| The tolerance value specifying how much of the sphere is "above" the sheet.

The documentation for this class was generated from the following files:

- SbSphereSheetProjector.h
- SbSphereSheetProjector.cpp