# generateLightMapTexture(withTextureSize:lightsToConsider:objectsToConsider:vertexAttributeNamed:materialPropertyNamed:) Calculates static lighting information for the mesh and saves it in the mesh as a material property texture of the specified size. ``` func generateLightMapTexture(withTextureSize textureSize: vector_int2, lightsToConsider: [MDLLight], objectsToConsider: [MDLObject], vertexAttributeNamed vertexAttributeName: String, materialPropertyNamed materialPropertyName: String) -> Bool ``` ## Parameters `textureSize` The size of texture image to generate. `lightsToConsider` An array of lights that should affect the mesh. `objectsToConsider` An array of other objects in the scene that should affect static lighting for the mesh. `vertexAttributeName` The name of the vertex attribute for storing generated texture coordinate data. `materialPropertyName` The name of the material for storing the generated texture image. ## Return Value if light map generation succeeded; otherwise . ## Discussion A light map contains, for each point on a surface, information about how light sources in a scene affect the shading of that surface. Because many of the lighting effects in a scene are static—that is, the positions of lights relative to the surfaces they illuminate do not change over time—you can achieve high-fidelity lighting effects with little render-time performance cost by using this method to precalculate (or “bake”) light information into a mesh. You can then use the resulting information in shading to produce a more realistic render. This method saves light map data as a texture image and associates that image with the mesh through the material property specified in the `materialPropertyName` parameter. To map the texture onto the mesh’s surface, this method also generates texture coordinates and writes them in the vertex attribute specified in the `vertexAttributeName` parameter. If the mesh already contains that attribute, this method overwrites the contents of the corresponding vertex buffer. If the mesh does not contain that attribute, this method creates a new attribute and updates the mesh’s [`vertexDescriptor`](/documentation/ModelIO/MDLMesh/vertexDescriptor) object accordingly. The `bakeQuality` parameter controls the fidelity and performance of the lighting calculation process and its output based on texture size. To control quality without specifying texture size, use the [`generateLightMapTexture(withQuality:lightsToConsider:objectsToConsider:vertexAttributeNamed:materialPropertyNamed:)`](/documentation/ModelIO/MDLMesh/generateLightMapTexture(withQuality:lightsToConsider:objectsToConsider:vertexAttributeNamed:materialPropertyNamed:)) method. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)