NAME

       SoOrthographicCamera -

       The SoOrthographicCamera class defines a camera node with orthographic rendering.

       Orthographic rendering will not give a particularly realistic impression of the scene, but
       non-realistic rendering is for various reasons widely used in applications for e.g.
       Computer Aided Design.

SYNOPSIS

       #include <Inventor/nodes/SoOrthographicCamera.h>

       Inherits SoCamera.

   Public Member Functions
       virtual SoType getTypeId (void) const
           Returns the type identification of an object derived from a class inheriting SoBase.
           This is used for run-time type checking and 'downward' casting.
       SoOrthographicCamera (void)
       virtual void scaleHeight (float scalefactor)
       virtual SbViewVolume getViewVolume (float useaspectratio=0.0f) const
       virtual void viewBoundingBox (const SbBox3f &box, float aspect, float slack)

   Static Public Member Functions
       static SoType getClassTypeId (void)
       static void initClass (void)

   Public Attributes
       SoSFFloat height

   Protected Member Functions
       virtual const SoFieldData * getFieldData (void) const
       virtual ~SoOrthographicCamera ()

   Static Protected Member Functions
       static const SoFieldData ** getFieldDataPtr (void)

   Additional Inherited Members

Detailed Description

       The SoOrthographicCamera class defines a camera node with orthographic rendering.

       Orthographic rendering will not give a particularly realistic impression of the scene, but
       non-realistic rendering is for various reasons widely used in applications for e.g.
       Computer Aided Design.

       Also, a simple technique for drawing overlay / HUD style graphics (often appearing to be
       in 2D) can be implemented by setting up a 'sub scene graph' with an SoOrthographicCamera
       and the geometry. As a simple demonstration of this concept, load this file into e.g. the
       ExaminerViewer:

       #Inventor V2.1 ascii

       Separator {
          PerspectiveCamera { position 0 0 5 }
          Cone { }

          Separator {
             OrthographicCamera {
                position -0.75 -0.75 2
             }
             BaseColor { rgb 1 1 0 }
             Sphere { radius 0.2 }
          }
       }

       You will likely encounter Z-buffer issues with this technique which makes the overlay /
       HUD graphics end up interspersed with the 'real' geometry. If so, this can be solved by
       e.g. inserting an SoCallback node in the sub-scene, where you let the callback disable the
       depth buffer with glDisable(GL_DEPTH_TEST).

       FILE FORMAT/DEFAULTS:

       OrthographicCamera {
           viewportMapping ADJUST_CAMERA
           position 0 0 1
           orientation 0 0 1  0
           nearDistance 1
           farDistance 10
           aspectRatio 1
           focalDistance 5
           height 2
       }

Constructor & Destructor Documentation

   SoOrthographicCamera::SoOrthographicCamera (void)
       Constructor.

   SoOrthographicCamera::~SoOrthographicCamera () [protected],  [virtual]
       Destructor.

Member Function Documentation

   SoType SoOrthographicCamera::getTypeId (void) const [virtual]
       Returns the type identification of an object derived from a class inheriting SoBase. This
       is used for run-time type checking and 'downward' casting. Usage example:

       void foo(SoNode * node)
       {
         if (node->getTypeId() == SoFile::getClassTypeId()) {
           SoFile * filenode = (SoFile *)node;  // safe downward cast, knows the type
         }
       }

       For application programmers wanting to extend the library with new nodes, engines,
       nodekits, draggers or others: this method needs to be overridden in all subclasses. This
       is typically done as part of setting up the full type system for extension classes, which
       is usually accomplished by using the pre-defined macros available through for instance
       Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes),
       Inventor/engines/SoSubEngine.h (for engine classes) and so on.

       For more information on writing Coin extensions, see the class documentation of the
       toplevel superclasses for the various class groups.

       Reimplemented from SoCamera.

   const SoFieldData * SoOrthographicCamera::getFieldData (void) const [protected],  [virtual]
       Returns a pointer to the class-wide field data storage object for this instance. If no
       fields are present, returns NULL.

       Reimplemented from SoCamera.

   void SoOrthographicCamera::scaleHeight (floatscalefactor) [virtual]
       Scale SoOrthographicCamera::height by multiplying with scalefactor.

       Implements SoCamera.

   SbViewVolume SoOrthographicCamera::getViewVolume (floatuseaspectratio = 0.0f) const [virtual]
       Returns total view volume covered by the camera under the current settings.

       This view volume is not adjusted to account for viewport mapping. If you want the same
       view volume as the one used during rendering, you should use
       getViewVolume(SbViewportRegion & vp, const SbMatrix & mm), or do something like this:

       SbViewVolume vv;
       float aspectratio = myviewport.getViewportAspectRatio();

       switch (camera->viewportMapping.getValue()) {
       case SoCamera::CROP_VIEWPORT_FILL_FRAME:
       case SoCamera::CROP_VIEWPORT_LINE_FRAME:
       case SoCamera::CROP_VIEWPORT_NO_FRAME:
         vv = camera->getViewVolume(0.0f);
         break;
       case SoCamera::ADJUST_CAMERA:
         vv = camera->getViewVolume(aspectratio);
         if (aspectratio < 1.0f) vv.scale(1.0f / aspectratio);
         break;
       case SoCamera::LEAVE_ALONE:
         vv = camera->getViewVolume(0.0f);
         break;
       default:
         assert(0 && "unknown viewport mapping");
         break;
       }.fi

       Also, for the CROPPED viewport mappings, the viewport might be changed if the viewport aspect ratio is not equal to the camera aspect ratio. See the SoCamera::getView() source-code (private method) to see how this is done.

       Implements SoCamera.

   void SoOrthographicCamera::viewBoundingBox (const SbBox3f &box, floataspect, floatslack)
       [virtual]
       Convenience method for setting up the camera definition to cover the given bounding box
       with the given aspect ratio. Multiplies the exact dimensions with a slack factor to have
       some space between the rendered model and the borders of the rendering area.

       If you define your own camera node class, be aware that this method should not set the
       orientation field of the camera, only the position, focal distance and near and far
       clipping planes.

       Implements SoCamera.

Member Data Documentation

   SoSFFloat SoOrthographicCamera::height
       Height of viewport in world-space scale. Defaults to 2.0 units.

Author

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