SceneTracer

The SceneTracer class provides an interface for performing ray intersection operations within a Scene using GPU shaders. To perform intersection, a new ray index must be obtained by atomically incrementing the indirect buffer, and input ray parameters must be written to the input buffer. The intersection result is then available in the output buffer at the same index on the next frame or after manually executing the dispatch() method. The SceneManager class offers a simpler interface to SceneTracer for CPU-initiated ray intersection queries, with results reported via callbacks.

info

The SceneTracer is available for GraphVarying shaders.

#include <scene/TellusimSceneTracer.h>

Constructors

SceneTracer()

Methods

Tracer parameters.

uint32_t getMaxRays() const

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Output buffer offset.

size_t getOutputOffset() const

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Tracer buffers.

Buffer getInputBuffer() const
Buffer getOutputBuffer() const
Buffer getIndirectBuffer() const

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Tracer queries.

Query getQuery(QueryType type) const
static const char *getQueryName(QueryType type)

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Dispatch tracer.

void dispatch(Compute compute, Flags flags = FlagNone)

Enums

Flags

Tracer flags.

Name	Value	Description
FlagNone	0
FlagQuery	(1 << 0)	Time query profiler.
DefaultFlags	FlagNone
NumFlags	1

---

RayFlags

Ray flags.

Name	Value	Description
RayFlagNone	0
RayFlagAll	(1 << 27)	Skip visibility distance test.
RayFlagAny	(1 << 28)	Stop on any object intersection.
RayFlagInstance	(1 << 29)	Stop on node instance intersection.
RayFlagDoubleSided	(1 << 30)	Perform double-sided intersection.

---

QueryType

Query types.

Name	Value	Description
QueryGraph	0	Graph tracing time.
QueryNode	1	Node tracing time.
QueryObject	2	Object tracing time.
QueryMesh	3	Mesh tracing time.
QueryBrep	4	Brep tracing time.
QueryMerge	5	Tracing merge time.
NumQueries	6

Structs

Ray

Tracer ray.

Variables

Type	Name	Value	Description
Matrix4x3d	transform		Global transform.
Vector3d	position		Ray position.
Vector3d	target		Ray target.
float32_t	k	1e8f	Intersection point.
uint32_t	mask	~0u	Intersection mask.
uint32_t	flags	RayFlagNone	Ray flags and ray index.
uint32_t	graph_index		Intersection graph index.
uint32_t	node_index		Intersection node index.
uint32_t	object_index		Intersection object index.
uint32_t	object_node_index		Intersection object node index.
uint32_t	geometry_index		Intersection object geometry index.
uint32_t	geometry_batch		Intersection object geometry batch.
uint32_t	geometry_primitive		Intersection object geometry primitive.
Vector2f	texcoord		Intersection texcoord.
Vector3f	normal		Intersection normal.
uint32_t	payload		Ray payload data.