API Reference — `dna/layers/GeometryWriter`

`class DNAAPI GeometryWriter : public virtual DefinitionWriter`

Write mesh geometry (vertex positions, texture coordinates, normals and layouts) into a rig. Write-only counterpart of the geometry reader.

When to use this

Use this interface when you need to populate or replace the mesh geometry layer of a DNA asset during a write pass. Pair with GeometryReader to read geometry back after writing, or combine multiple set* calls to progressively build up mesh data before committing.

Use it when you populate or edit the mesh data of a rig. Do not inherit from it directly. Implementors should inherit from Writer instead.

Method groups

Group	Methods
Meshes	clearMeshes, deleteMesh
Vertex positions	setVertexPositions
Vertex texture coordinates	setVertexTextureCoordinates
Vertex normals	setVertexNormals
Vertex layouts	setVertexLayouts

Example

// Obtain a Writer (which also implements GeometryWriter) via factory
dna::Writer* writer = dna::Writer::create(stream, memRes);

// Set vertex positions for mesh 0
std::vector<dna::Position> positions = { {0.0f, 1.0f, 0.0f}, {1.0f, 0.0f, 0.0f} };
writer->setVertexPositions(0, positions.data(), static_cast<std::uint32_t>(positions.size()));

// Set normals for mesh 0
std::vector<dna::Normal> normals = { {0.0f, 0.0f, 1.0f}, {0.0f, 0.0f, 1.0f} };
writer->setVertexNormals(0, normals.data(), static_cast<std::uint32_t>(normals.size()));

// Set texture coordinates for mesh 0
std::vector<dna::TextureCoordinate> uvs = { {0.5f, 0.5f}, {1.0f, 0.0f} };
writer->setVertexTextureCoordinates(0, uvs.data(), static_cast<std::uint32_t>(uvs.size()));

// Remove a mesh no longer needed
writer->deleteMesh(2);

Parameters

Name	Type	Description
`meshIndex`	`std::uint16_t`	required — zero-indexed position of the target mesh. Must be less than `getMeshCount` for `deleteMesh`; implicitly resizes storage for `set*` methods.
`positions`	`const Position*`	required — source buffer of `Position` values to copy into the mesh.
`textureCoordinates`	`const TextureCoordinate*`	required — source buffer of `TextureCoordinate` values to copy into the mesh.
`normals`	`const Normal*`	required — source buffer of `Normal` values to copy into the mesh.
`layouts`	`const VertexLayout*`	required — source buffer of `VertexLayout` values to copy into the mesh.
`count`	`std::uint32_t`	required — number of elements to copy from the corresponding source buffer.

Constraints

For deleteMesh, meshIndex must be less than the value returned by getMeshCount.

Watch out for

The setters implicitly resize mesh storage, if needed, to fit the number of meshes inferred from meshIndex.
The destructor is protected, so you cannot delete an instance through this interface.

API Reference — dna/layers/GeometryWriter

class DNAAPI GeometryWriter : public virtual DefinitionWriter