Camera Nodes

Camera initialization and update, and custom camera node implementation. More...

Data Structures
struct	AtCameraInput
	Camera ray creation inputs. More...
struct	AtCameraOutput
	Camera ray creation outputs. More...
struct	AtCameraNodeMethods
	Camera node methods structure. More...

Macros
#define	AI_CAMERA_NODE_EXPORT_METHODS(tag)
	Camera node methods exporter. More...

Variables
float	AtCameraInput::sx
float	AtCameraInput::sy
	screen-space coordinates will range between (screen_window_min.x, screen_window_min.y/frame_aspect_ratio) and (screen_window_max.x, screen_window_max.y/frame_aspect_ratio)
float	AtCameraInput::dsx
float	AtCameraInput::dsy
	derivatives of the screen-space coordinates with respect to pixel coordinates
float	AtCameraInput::lensx
float	AtCameraInput::lensy
	lens sampling coordinates in [0,1)^2
float	AtCameraInput::relative_time
	time relative to this camera (in [0,1))
AtVector	AtCameraOutput::origin
	ray origin in camera space (required)
AtVector	AtCameraOutput::dir
	ray direction in camera space (required)
AtVector	AtCameraOutput::dOdx
AtVector	AtCameraOutput::dOdy
	derivative of the ray origin with respect to the pixel coordinates (optional - defaults to 0)
AtVector	AtCameraOutput::dDdx
AtVector	AtCameraOutput::dDdy
	derivative of the ray direction with respect to the pixel coordinates (optional - defaults to 0)
AtRGB	AtCameraOutput::weight
	weight of this ray (used for vignetting) (optional - defaults to AI_RGB_WHITE)
void(*	AtCameraNodeMethods::CreateRay )(const AtNode *, const AtCameraInput &, AtCameraOutput &, uint16_t tid)
bool(*	AtCameraNodeMethods::ReverseRay )(const AtNode *node, const AtVector &Po, float relative_time, AtVector2 &Ps)

API Methods for Camera Writers
AI_API void	AiCameraInitialize (AtNode *node)
	Initialize the camera's internal data. More...
AI_API void	AiCameraUpdate (AtNode *node, bool plane_distance)
	Updates camera's internal data. More...

Node Method Declarations
#define	camera_create_ray   static void CameraCreateRay(const AtNode* node, const AtCameraInput& input, AtCameraOutput& output, uint16_t tid)
	Camera's camera_create_ray method declaration. More...
#define	camera_reverse_ray   static bool CameraReverseRay(const AtNode* node, const AtVector &Po, float relative_time, AtVector2 &Ps)
	Camera's camera_reverse_ray method declaration. More...

Detailed Description

Camera initialization and update, and custom camera node implementation.

Macro Definition Documentation

AI_CAMERA_NODE_EXPORT_METHODS

#define AI_CAMERA_NODE_EXPORT_METHODS

(

tag

)

Value:

AI_INSTANCE_COMMON_METHODS                   \
camera_create_ray;                           \
camera_reverse_ray;                          \
static AtCameraNodeMethods ai_cam_mtds = {   \
   CameraCreateRay,                          \
   CameraReverseRay                          \
};                                           \
static AtNodeMethods ai_node_mtds = {        \
   &ai_common_mtds,                          \
   &ai_cam_mtds                              \
};                                           \
const AtNodeMethods* tag = &ai_node_mtds;

Camera node methods exporter.

camera_create_ray

#define camera_create_ray   static void CameraCreateRay(const AtNode* node, const AtCameraInput& input, AtCameraOutput& output, uint16_t tid)

Camera's camera_create_ray method declaration.

This function is called for the camera to return a ray origin and direction given a point in 2d screen coordinates.

Parameters

	node	pointer to the camera node itself
	input	AtCameraInput data required to generate a new ray (screen position, derivatives, etc...)
[out]	output	Camera ray origin, direction and weight. Derivatives are set to zero by default. Estimates will be computed if they are not set.
	tid	thread ID that will cast this ray

camera_reverse_ray

#define camera_reverse_ray   static bool CameraReverseRay(const AtNode* node, const AtVector &Po, float relative_time, AtVector2 &Ps)

Camera's camera_reverse_ray method declaration.

This function is the reverse of camera_create_ray: given a point in camera space 3d coordinates return the corresponding 2d screen coordinates.

Parameters

	node	pointer to the camera node itself
	Po	Point in camera space
	relative_time	Relative time to compute the projection in
[out]	Ps	Output point in screen space

Returns

True if a screen space projection exists and False otherwise. Points that fall outside the frame should return True and compute the corresponding screen coordinates, only points with no projection at all should return False. False can also be returned if there's no implementation available.

Function Documentation

AiCameraInitialize()

AI_API void AiCameraInitialize

(

AtNode *

node

)

Initialize the camera's internal data.

This must be called once and only once during node_initialize

Parameters

node	pointer to the camera node

AiCameraUpdate()

AI_API void AiCameraUpdate	(	AtNode *	node,
		bool	plane_distance
	)

Updates camera's internal data.

This must be called during node_update

Parameters

node	pointer to the camera node
plane_distance	will the Z-depth and near/far clip be computed from the camera plane, or from the camera point?