Hi, can someone give me a starting example of how to write an openexr file into disk? I tried the following toy example to write a 2-by-2 checker-box:
import ModelIO
var floatData = UnsafeMutableBufferPointer<Float32>.allocate(capacity: 4)
floatData[0] = Float32(0.99)
floatData[1] = Float32(0.0)
floatData[2] = Float32(0.0)
floatData[3] = Float32(0.99)
var floatBuffer = Data(buffer: floatData)
let exrImg = MDLTexture(data: floatBuffer,
topLeftOrigin: true,
name: "output.exr",
dimensions: SIMD2<Int32>(2,2),
rowStride: 2 * MemoryLayout<Float32>.size,
channelCount: 1,
channelEncoding: MDLTextureChannelEncoding.float32,
isCube: false)
let resourcesURL = URL(fileURLWithPath: "/Users/myDirectory", isDirectory: true)
let fileName = resourcesURL.appendingPathComponent(exrImgTest.name)
if(exrImg.write(to: fileName)){
print("Success! Image written in disk")
} else {
print("could not write image")
}
When I run this I get thread 1: EXC_BAD_ACCESS (code=1, address=0xf0) pointing to the write method of the MDLTexture. If I change the name to output.png the image is written without a problem.
I guess I am missing something basic here. Moreover, how could I write a multiple channel openEXR image to disk?
jacubit
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Post
Replies
Boosts
Views
Activity
I tried it with the following code with a larger image:
import ModelIO
if #available(macOS 11.0, *) {
var floatData = UnsafeMutableBufferPointer<Float32>.allocate(capacity: 16*16)
for i in 0..<256{
if (i%2 == 0){
floatData[i] = Float32(0.99)
} else {
floatData[i] = Float32(0)
}
}
let floatBuffer = Data(buffer: floatData)
let exrImg = MDLTexture(data: floatBuffer,
topLeftOrigin: true,
name: "output.exr",
dimensions: SIMD2<Int32>(16,16),
rowStride: 16 * MemoryLayout<Float32>.size,
channelCount: 1,
channelEncoding: MDLTextureChannelEncoding.float32,
isCube: false)
let resourcesURL = URL(fileURLWithPath: "/Users/myDirectory", isDirectory: true)
let fileName = resourcesURL.appendingPathComponent(exrImg.name)
if(exrImg.write(to: fileName)){
print("Success! Image written in disk")
} else {
print("could not write image")
}
} else {
// Fallback on earlier versions
}
I get the following runtime error:
Error>: kvImagePrintDiagnosticsToConsole: vImageConverter: In this version of the converter, most pixel formats must be packed arrays of samples with no empty space, except as appropriate for kCGImageAlphaNoneSkipFirst/Last. Here, the colorspace has 1 channels, with 1 more for alpha, which should mean (1+1 channels/pixel)*16 bits per channel = 32 bits per pixel. You passed 16 in format->bitsPerPixel.
doubling the size of the buffer and changing the Float32 to Float16 did not work either. The write method returns false.