I'm using vuforia-sdk-ios-2-0-32. I referred below link for taking screenshot (including both camera and 3D content) . https://developer.vuforia.com/forum/ios/vuforia-sdk-how-take-screenshots , https://developer.vuforia.com/forum/ios/take-screenshot . But my code taking only camera image and save to Album but it's not taking withoverlay content (3D content or image).
ARParentViewController.mm :
-(void)screenshot:(id)sender{
 UIImage *outputImage = nil;
        CGFloat scale = [[UIScreen mainScreen] scale];
    CGRect  s = CGRectMake(0, 0, (768.0f) * scale, 1024.0f * scale);
 uint8_t *buffer = (uint8_t *) malloc(s.size.width * s.size.height * 4);
 glReadPixels(0, 0, s.size.width, s.size.height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
   CGDataProviderRef ref = CGDataProviderCreateWithData(NULL, buffer, s.size.width * s.size.height * 4, NULL);
     CGImageRef iref = CGImageCreate(s.size.width, s.size.height, 8, 32, s.size.width * 4, CGColorSpaceCreateDeviceRGB(), kCGBitmapByteOrderDefault, ref, NULL, true, kCGRenderingIntentDefault);
   size_t width = CGImageGetWidth(iref);
    size_t height = CGImageGetHeight(iref);
    size_t length = width * height * 4;
    uint32_t *pixels = (uint32_t *)malloc(length);
   CGContextRef context = CGBitmapContextCreate(pixels, width, height, 8, width * 4,
    CGImageGetColorSpace(iref), kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Big);
   CGAffineTransform transform = CGAffineTransformIdentity;
        transform = CGAffineTransformMakeTranslation(0.0f, height);
        transform = CGAffineTransformScale(transform, 1.0, -1.0);
        CGContextConcatCTM(context, transform);
        CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, width, height), iref);
        CGImageRef outputRef = CGBitmapContextCreateImage(context);
   outputImage = [UIImage imageWithCGImage: outputRef];
       CGDataProviderRelease(ref);
        CGImageRelease(iref);
        CGContextRelease(context);
        CGImageRelease(outputRef);
        free(pixels);
        free(buffer);
    UIImageWriteToSavedPhotosAlbum(outputImage, nil, nil, nil);
}
AR_EAGLView.mm:
eaglLayer.drawableProperties = @{
                                    kEAGLDrawablePropertyRetainedBacking: [NSNumber numberWithBool:YES],
                                    kEAGLDrawablePropertyColorFormat: kEAGLColorFormatRGBA8,
      };