THREE.NodeBuilder: Type '${type}' not found in generate cons

Error message

THREE.NodeBuilder: Type '${type}' not found in generate constant attempt.

What it means

Thrown by NodeBuilder.generateConst() when no branch handles the requested `type`/`value` pair. Scalar types (float/int/uint/bool/color) return earlier; the remaining branches cover typeLength 2, 3, 4 (non-mat2), matrices, and >4. The throw is reached for an unknown/unregistered type (typeLength 0), or for `mat2` with a non-matrix value.

Source

Thrown at src/nodes/core/NodeBuilder.js:1457

		} else if ( typeLength === 3 ) {

			return `${ this.getType( type ) }( ${ generateConst( value.x ) }, ${ generateConst( value.y ) }, ${ generateConst( value.z ) } )`;

		} else if ( typeLength === 4 && type !== 'mat2' ) {

			return `${ this.getType( type ) }( ${ generateConst( value.x ) }, ${ generateConst( value.y ) }, ${ generateConst( value.z ) }, ${ generateConst( value.w ) } )`;

		} else if ( typeLength >= 4 && value && ( value.isMatrix2 || value.isMatrix3 || value.isMatrix4 ) ) {

			return `${ this.getType( type ) }( ${ value.elements.map( generateConst ).join( ', ' ) } )`;

		} else if ( typeLength > 4 ) {

			return `${ this.getType( type ) }()`;

		}

		throw new Error( `THREE.NodeBuilder: Type '${type}' not found in generate constant attempt.` );

	}

	/**
	 * It might be necessary to convert certain data types to different ones
	 * so this method can be used to hide the conversion.
	 *
	 * @param {string} type - The type.
	 * @return {string} The updated type.
	 */
	getType( type ) {

		if ( type === 'color' ) return 'vec3';

		return type;

	}

View on GitHub (pinned to da05705fa3)

Solutions

Ensure the node's getNodeType()/nodeType returns a built-in type string the builder recognizes (float, vec2/3/4, mat2/3/4, etc.).
If the value is a matrix, pass an actual Matrix2/3/4 instance rather than a plain object.
Register/handle the custom type, or convert the node to emit a recognized type before const generation.

Defensive patterns

Strategy: validation

Validate before calling

const KNOWN_TYPES = new Set( [ 'float','int','uint','bool','color','vec2','vec3','vec4','ivec2','ivec3','ivec4','uvec2','uvec3','uvec4','mat2','mat3','mat4' ] );
function assertKnownType( type ) {
  if ( ! KNOWN_TYPES.has( type ) ) throw new TypeError( `generateConst: unknown type '${ type }'` );
}

Type guard

const isKnownScalarType = ( t ) => typeof t === 'string' && /^[iu]?(vec[234]|float|int|uint|bool|color|mat[234])$/.test( t );

Prevention

Ensure custom nodes return a recognized primitive type from getNodeType().
Pass Matrix2/3/4 instances, not plain objects, for matrix constants.
Validate inferred types during node-graph construction, not at render time.

When it happens

Trigger: A node reports a custom/unknown type string that NodeBuilder.getTypeLength() cannot resolve; generating a constant for a struct or array type; passing a plain object instead of a Matrix2/3/4 when the type is a matrix; a node returning an empty/undefined type from getNodeType().

Common situations: Authoring a custom node that returns a non-standard type; type inference failing because getNodeType() returns null/undefined; a uniform or attribute typed with a string the builder does not recognize; corrupt node graph after partial refactors.

Related errors

AI-assisted analysis of mrdoob/three.js@da05705fa3 (2026-08-12). Data as JSON: /api/errors/425b9c96f5b50726. Report an issue: GitHub.