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How to get CATransform3D from Projection and ModelView matrices

I have browse this question before，the url；but it wasn't absolutely precise; I want to know why it’s not precise；

I find that the rotate by x--axis and y--axis is opposite（I can't post image）；the Trapezoidal(when rotate the calayer , it's like a Trapezoidal) is opposite，dose calayer rotate is not like opengl？but it's right when rotate by z--axis.

I want get the Angle and then rotate it twice opposite；how to get Angle by the opengl matrices？

I want play movie by QCAR; I can get opengl matrices,and I want to use UIView to playe movie and other(Familiar with the UIView),and make UIview like Texture.

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louhubiao
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1 Answers1

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I just post a example on QCAR forum, you can check the detail here

The idea is simple.

1.I don't use avassetreader to read the video pixel, instead I use AVPlayer and AVPlayerLayer which can play remote video file.

2.I need to convert opengl modelview matrix to CATransform3D so the AVPlayerLayer will attach on the trackable image.Thanks for Hammer on stackoverflow, he shared an example about how to make this.

3.I tried to render camera background use opengl and AVPlayerLayer at same time, but the performace is not good enough, so I use another calayer to render the camera background. There is a bug in 1.5.8 when getting camera frame, thank for andersfrank the problem was solved here.

I put my code on pastebin:

http://pastebin.com/kmeVZ7jy

There are still some problem need to solve, but I think this is a right approach.

PS. For question 3 in my original post, you can fix it by set

        cameraLayer.contentsGravity = kCAGravityResizeAspectFill;

This will fix the problem that the aspect ratio of the camera image is different with the iphone screen's.

Update

All the problem are solved, please check my original post on vuforia and pastebin.

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Tim
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