# GLKMatrix4MultiplyAndProjectVector3Array(_:_:_:) Multiplies a `4x4` matrix by an array of `3`-component vectors. Each result is projected back to `3`-component vector. ``` func GLKMatrix4MultiplyAndProjectVector3Array(_ matrix: GLKMatrix4, _ vectors: UnsafeMutablePointer, _ vectorCount: Int) ``` ## Parameters `matrix` The matrix multiplicand. `vectors` On entry, an array of input vectors. On return, an array of output vectors. `vectorCount` The number of vectors in the array. ## Discussion --- 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)