simd provides types and functions for small vector and matrix computations.

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Issue storing SIMD3<Float> (and other simd’s) in a SwiftData model
I'm encountering an issue when trying to store a SIMD3<Float> in a SwiftData model. Since SIMD3<Float> already conforms to Codable, I expected it to work. However, attempting to store a single SIMD3<Float> crashes with the following error: Fatal error: Unexpected property within Persisted Struct/Enum: Builtin.Vec4xFPIEEE32 Interestingly, storing an array of vectors, [SIMD3<Float>], works perfectly fine. The issue only arises when trying to store a single SIMD3<Float>. I’m not looking for a workaround (I can break the vector into individual floats in a custom codable struct to get by) , but I’d like to understand why storing a codable SIMD3<Float> in SwiftData results in this crash. Is this a limitation of SwiftData, or is there something I’m missing about how vectors are handled? Any insights would be greatly appreciated!
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Sep ’24
Placing object in AR without hittest or plane
Hi, i want to place a object in 3d world space without the use of hittest or plane detection in ios swift code. Suggest the best method. Now, I take the camera center matrix and use simd_mul to place the object, it works but the object gets placed at the centre of the mobile screen. I want to select the x and y positino on the screen 2d coordinate and place the object. I tried using the unprojectpoint function, to get the AR scene world coordinate of the point i touch on the mobile screen. I get the x, y,z values, they are very close to the values from camera center matrix. When i try to replace the unprojectpoint values in the cameracenter matrix, i dont see a difference in the location of the placed object. The below code always place object from center screen with specified depth, But i need to place object in user specified position(x,y) of the screen with depth. 2D pixel coordinate system of the renderer to the 3D world coordinate system of the scene. /* Create a transform with a translation of 0.2 meters in front of the camera. */ var translation = matrix_identity_float4x4 translation.columns.3.z = -0.2 let transform = simd_mul(view.session.currentFrame.camera.transform, translation) Refer from : [https://developer.apple.com/documentation/arkit/arskview/providing_2d_virtual_content_with_spritekit) The code i used for replacing the camera center matrix with the unprojectpoint is let vpWithZ = SCNVector3(x: 100.0, y: 100.0, z: -1.0) let worldPoint = sceneView.unprojectPoint(vpWithZ) var translation = matrix_identity_float4x4 translation.columns.3.z = Float(Depth) var translation2 = sceneView.session.currentFrame!.camera.transform translation2.columns.3.x = worldPoint.x translation2.columns.3.y = worldPoint.y translation2.columns.3.z = worldPoint.z let new_transform = simd_mul(translation2, translation) /* add object name you wanted in your project*/ let sphere = SCNSphere(radius: 0.03) let objectNode = SCNNode(geometry: sphere) objectNode.position = SCNVector3(x: transform.columns.3.x, y: transform.columns.3.y, z: transform.columns.3.z) The below image shows outline of my idea.
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534
Apr ’24
sims_4x4 data
I'm trying to decipher this roomplan api data output. Dimensions: the simd3 is width and height and I think thickness in meters but the spacial information is not clear to me and I can't find any info on it. an insights on this? *** CAPTURED ROOM OBJECTS *** Walls: Identifier: 9F4BEEBB-990C-42F3-A0BC-912E1F770877 Dimensions: SIMD3(5.800479, 2.4299998, 0.0) Category: wall Transform: SIMD4(0.25821668, 0.0, 0.966087, 0.0) SIMD4(0.0, 1.0, 0.0, 0.0) SIMD4(-0.966087, 0.0, 0.2582167, 0.0) SIMD4(2.463065, -0.27346277, -0.5366996, 1.0) Identifier: A72544F5-068D-4F19-8FA4-60C1331003E3 Dimensions: SIMD3(2.28993, 2.4299998, 0.0) Category: wall Transform: SIMD4(0.966087, 0.0, -0.2582166, 0.0) SIMD4(0.0, 1.0, 0.0, 0.0) SIMD4(0.25821656, 0.0, 0.966087, 0.0) SIMD4(0.608039, -0.27346277, -3.0429342, 1.0)
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Mar ’24