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A CameraObject represents a camera in Cinema 4D . It is based on BaseObject (见 BaseObject Manual ).

CameraObject objects are an instance of Ocamera .

Access

A CameraObject is typically obtained from a BaseDraw representing a viewport window. This BaseDraw is obtained from the a BaseDocument .

// This example gets the currently used camera.

BaseDraw * const bd = doc-> GetActiveBaseDraw (); if (bd == nullptr ) return maxon::UnexpectedError( MAXON_SOURCE_LOCATION );

BaseObject * camera = bd-> GetSceneCamera (doc); if (camera == nullptr ) camera = bd-> GetEditorCamera (); if (camera == nullptr ) return maxon::UnexpectedError( MAXON_SOURCE_LOCATION ); ApplicationOutput ( "Camera name: @" , maxon::String { camera-> GetName () });

注意: Cinema 4D can use any object as a "camera" so the returned BaseObject may or may not be a CameraObject . One can check if it is a CameraObject with C4DAtom::IsInstanceOf() .

Also a generator can contain a CameraObject . To get the real camera from that generator a message has to be sent to that generator:

MSG_GETREALCAMERADATA : Message ID sent to get a real camera object from a generator. The corresponding data is GetRealCameraData .
GetRealCameraData::res : The real camera object provided by the generator.

// This example tries to get the internal camera from a generator. // Typically used with the Alembic Generator camera. GetRealCameraData data;

// send the message to the object to get the "real camera" // and check the result if (obj-> 消息 ( MSG_GETREALCAMERADATA , &data) && data. res ) obj = data. res ; ApplicationOutput ( "Camera: @" , maxon::String { obj-> GetName () });

CameraObject objects are created with the usual tools:

A new or existing camera can be set as the active scene camera:

BaseDraw::SetSceneCamera() : Sets the given BaseObject as the used scene camera.

// This example creates a new camera object and uses it as the scene camera. CameraObject * const camera = CameraObject::Alloc (); if (camera == nullptr ) return maxon::OutOfMemoryError( MAXON_SOURCE_LOCATION ); doc-> InsertObject (camera, nullptr , nullptr ); camera-> SetName ( "The new camera" _s); const 矩阵 mg = MatrixMove ( 向量 (0, 0, -500)); camera-> SetMg (mg); BaseDraw * const bd = doc-> GetActiveBaseDraw (); if (bd) bd-> SetSceneCamera (camera);

The parameters of a CameraObject are edited as usual with C4DAtom::GetParameter() and C4DAtom::SetParameter() . The parameter IDs are defined in Ocamera.h .

警告: Some parameters of the camera are "virtual" ( CAMERAOBJECT_FOV and CAMERAOBJECT_FOV_VERTICAL ) and cannot be accessed in any situation.

For some parameters dedicated functions exist.

These functions access the camera projection setting:

// This example sets the projection of the selected camera object to "Parallel". BaseObject * const obj = doc-> GetActiveObject ();

// the function needs a selected camera to get executed if (obj == nullptr || !obj-> IsInstanceOf ( Ocamera )) return maxon::IllegalArgumentError( MAXON_SOURCE_LOCATION ); CameraObject * const camera = static_cast< CameraObject * > (obj); camera-> SetProjection ( Pparallel );

These functions set the camera zoom value:

These functions set the camera position. This is the midpoint for orthogonal projections (Front/Back/Top/Bottom etc.).

These functions set the camera aperture value:

These functions set the camera focus value:

A CameraObject can also store information about the stereoscopic cameras it represents.

The stereo camera information is stored in a StereoCameraInfo structure object:

// This example loops through the stereo cameras of the given camera object. CameraObject * const camera = static_cast< CameraObject * > (obj); RenderData * const renderData = doc-> GetActiveRenderData (); BaseDraw * const bd = doc-> GetActiveBaseDraw (); if (bd == nullptr ) return maxon::UnexpectedError( MAXON_SOURCE_LOCATION ); const Int32 stereoCount = camera-> StereoGetCameraCount (doc, bd, renderData, 0); for ( Int32 i = 0; i < stereoCount; ++i) { StereoCameraInfo info; camera-> StereoGetCameraInfo (doc, bd, renderData, i, info, 0); ApplicationOutput ( "Stereo Camera name: @" , maxon::String { info. strName }); }