BillboardGeometry class Geometry

A batch of camera-facing quads ("billboards"), expanded from per-instance data in the vertex shader and drawn in a single instanced call.

Each instance carries a center, a size, an in-plane rotation, a linear RGBA color, a flipbook frame, and a velocity (used only by BillboardFacing.velocityStretched). The center is in the geometry's local space; the owning node's transform places and orients the whole batch. Pair it with a SpriteMaterial (or any material whose fragment shader reads v_uv and v_color).

Write instance data into instanceData (a flat Float32List of floatsPerInstance floats each) and call commit with the live count. The batch is the backing primitive for sprites, impostors, and the particle sprite renderer.

Inheritance

Constructors

BillboardGeometry({int capacity = 256})
Creates a billboard batch sized for up to capacity instances.

Properties

bindsModelTransformInstance → bool
Whether the color encoder should bind the node's model transform as a one-element instance-rate buffer at the slot after this geometry's vertex streams.
no setter
capacity → int
The maximum number of instances this batch can draw.
final
facing ↔ BillboardFacing
How the quads orient toward the camera.
getter/setter pair
flipbookBlend ↔ bool
When true, fractional frame values crossfade between the two adjacent flipbook cells (wrapping at the end of the grid) instead of snapping to the nearest cell, so low-rate flipbooks still animate smoothly.
getter/setter pair
flipbookColumns ↔ int
Flipbook atlas columns and rows. 1 x 1 (the default) samples the whole texture; larger grids select the cell for each instance's frame.
getter/setter pair
flipbookRows ↔ int
getter/setter pair
hashCode → int
The hash code for this object.
no setterinherited
instanceCount → int
The number of instances drawn last commit.
no setter
instanceData → Float32List
The flat per-instance buffer the caller writes into, capacity * floatsPerInstance floats long. Lay out each instance as: center x,y,z; size x,y; rotation; color r,g,b,a; frame; velocity x,y,z. Call commit after writing.
no setter
instancedVertexLayout → VertexLayoutDescriptor?
The explicit pipeline vertex layout this geometry's vertex shader expects, or null for the shader bundle's default interleaved layout.
no setter
isDoubleSided → bool
Whether this geometry should be drawn without back-face culling.
no setter
isReadable → bool Geometry
Whether this geometry retains CPU-side vertex data, making extractMeshData available.
no setterinherited
localBoundingSphere → Sphere?
Local-space bounding sphere paired with localBounds. Same nullability semantics.
no setterinherited
localBounds → Aabb3?
Local-space axis-aligned bounding box of this geometry's vertex positions, or null if bounds are unknown. Computed by uploadVertexData for procedural geometry, populated from baked scene-package bounds for imported geometry, and (for the advanced setVertices path where the caller manages its own GPU buffer) left null unless the caller assigns it via setLocalBounds.
no setterinherited
primitiveType ↔ PrimitiveType
How the vertex/index data is assembled into primitives when drawn.
getter/setter pairinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
velocityStretch ↔ double
World units of extra length added per unit of speed in BillboardFacing.velocityStretched.
getter/setter pair
vertexShader → Shader
The vertex shader used when rendering this geometry.
no setterinherited
worldUp ↔ Vector3
The world up axis used to build the billboard basis (and the locked axis for BillboardFacing.axisLocked). Defaults to +Y.
getter/setter pair

Methods

bind(RenderPass pass, TransientWriter transientsBuffer, Matrix4 modelTransform, Matrix4 cameraTransform, Vector3 cameraPosition, {Shader? shaderOverride}) → void
Binds vertex/index buffers and per-frame uniforms onto pass in preparation for a draw call.
override
commit(int count) → void
Sets the number of live instances to draw and recomputes the batch's local bounds from their centers and sizes (so the owning item culls and, with an LodComponent, measures its screen size correctly).
draw(RenderPass pass, {int instanceCount = 1}) → void
Emits this geometry's draw call after bind has prepared the render pass.
override
extractMeshData() → MeshData Geometry
Copies this geometry's retained CPU vertex/index data out as an isolate-transferable MeshData snapshot.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
setCustomAttribute(String name, Float32List data, {required int components}) → void Geometry
Attaches a custom per-vertex attribute stream named name, matching a material's attributes entry (and the generated shader's in <name>).
inherited
setIndices(BufferView indices, IndexType indexType) → void
Binds an already-uploaded index buffer view, with element width determined by indexType.
inherited
setInstance(int index, {required Vector3 center, required double width, required double height, double rotation = 0.0, Vector4? color, double frame = 0.0, Vector3? velocity}) → void
Writes one instance's fields at index into instanceData. A convenience over hand-indexing the flat buffer; call commit when done.
setJointsTexture(Texture? texture, int width) → void
Hook for skinned geometries to receive the joints texture computed by Skin.getJointsTexture.
inherited
setLocalBounds(Aabb3? aabb, Sphere? sphere) → void
Override the bounds. Useful for callers driving setVertices from a caller-managed gpu.DeviceBuffer who want to participate in bounds-driven scene queries (e.g. frustum culling).
inherited
setVertexShader(Shader shader) → void
Assigns the vertex shader used when this geometry is drawn.
inherited
setVertexShaderName(String name) → void
Assigns the vertex shader by name from baseShaderLibrary.
inherited
setVertices(BufferView vertices, int vertexCount) → void
Binds an already-uploaded vertex buffer view as this geometry's vertex source.
inherited
toString() → String
A string representation of this object.
inherited
uploadVertexData(ByteData vertices, int vertexCount, ByteData? indices, {IndexType indexType = gpu.IndexType.int16}) → void
Allocates a gpu.DeviceBuffer and uploads vertices (and optional indices) into it in one step.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Constants

floatsPerInstance → const int
The number of floats per instance in instanceData: center (3), size (2), rotation (1), color (4), flipbook frame (1), velocity (3).