Can't display 3d file from cache directory

问题

Can you please help me determine the problem here?

It seems that I can't display the 3d file from cache directory. I'm having this error SceneKit IO: error, COLLADA files are not supported on this platform.

The zip file im saving in the cache directory contains .dae file and .png for the texturee. With Scene Kit you can:

Import COLLADA 3D objects and build scenes composed by cameras, lights, and meshes. https://developer.apple.com/library/mac/documentation/3DDrawing/Conceptual/SceneKit_PG/Introduction/Introduction.html

Thanks.

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
    NSURL *url = [NSURL URLWithString:@"my url"
    NSData *data = [NSData dataWithContentsOfURL:url options:0 error:&error];

    if(!error)
    {
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
        NSString *path = [paths objectAtIndex:0];
        NSString *zipPath = [path stringByAppendingPathComponent:@"zipfile.zip"];

        [data writeToFile:zipPath options:0 error:&error];

        if(!error)
        {
            ZipArchive *za = [[ZipArchive alloc] init];
            if ([za UnzipOpenFile: zipPath]) {
                BOOL ret = [za UnzipFileTo: path overWrite: YES];
                if (NO == ret){} [za UnzipCloseFile];

                NSString *floorFilePath = [path stringByAppendingPathComponent:@"house1.dae"];
                NSURL *floorPathURL = [NSURL fileURLWithPath:floorFilePath];
                dispatch_async(dispatch_get_main_queue(), ^{

                    SCNView *sceneView = (SCNView *)self.view;
                    sceneView = (SCNView *)self.view;
                    sceneView.allowsCameraControl = YES;
                    sceneView.autoenablesDefaultLighting = YES;
                    sceneView.backgroundColor = [UIColor whiteColor];
                    sceneView.scene = [SCNScene sceneWithURL:floorPathURL options:nil error:nil];
                });
            }
        }
        else
        {
            NSLog(@"Error saving file %@",error);
        }
    }
    else
    {
        NSLog(@"Error downloading zip file: %@", error);
    }

});

回答1:

The SCNSceneSource Class Reference has a table:

Format                          Filename Extension    Supported in

Collada Digital Asset Exchange  .dae                  OS X v10.8 and later

Alembic                         .abc                  OS X v10.10 and later

SceneKit compressed scene       .dae or .abc          OS X v10.10 and later
                                                      iOS 8.0 and later

SceneKit archive                .scn                  OS X v10.10 and later
                                                      iOS 8.0 and later

Are you sure your .dae file is a “SceneKit compressed scene”? Apparently, iOS only supports loading compressed scenes from .dae files. Xcode should automatically convert your Collada .dae to a compressed scene (with the same extension) when it compiles your app. If you're loading the file from outside your app bundle (e.g. from a URL at runtime), it won't be a SceneKit compressed scene unless you've taken steps to convert it elsewhere.

I found the following comment on this answer:

To convert the dae file to a file that can be read by SCNScene(named:... you can convert the file manually by using the following commandline in terminal: /Applications/Xcode.app/Contents/Developer/usr/bin/scntool --convert InFile.dae --format c3d --output OutFile.dae --force-y-up --force-interleaved --look-for-pvrtc-image (Of course, replace InFile.dae and OutFile.dae by your own filenames) Sorry, no real formatting possible in comments. – Marcus Feb 2 at 18:23

I don't know if all those flags are appropriate for your use. According to this web site, there's also a command-line program named copySceneKitAssets (in the same Xcode subdirectory) that converts .scnassets directories, so maybe that's what you want to use.

来源：https://stackoverflow.com/questions/30097948/cant-display-3d-file-from-cache-directory

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ios

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scenekit

collada