This article applies only to the Augmented Reality SDK.
There are certain applications, such as interactive catalogs where the user is interested in viewing a 3D model from a different angle or even, you want to animate the model such that it spins continuously. Such interaction can be implemented by programmatically rotating and translating the 3D model.
The Augmented Reality SDK lets you render 3D models into the AR scene. This article explains how to change the viewpoint of a 3D model at run-time with a few lines of code on iOS and on Android.
In the example of this article, we added a slider in our layout. When the user slides, the 3D model is rotated.
Below are two screenshots of a 3D model with different values of the slider.
Rotate the model on Android
In order to modify the content’s rotation, we need to implement the Slider’s OnSeekBarChangeListener and modify our content’s rotation matrix:
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SeekBar slider = (SeekBar)mainLayout.findViewById(R.id.zSlider);
slider.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
// Create rotation matrix on z axis
float[] rotation = new float[16];
Matrix.setRotateEulerM(rotation, 0, 0, 0, progress);
modelContent.setRotationMatrix(rotation);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
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Rotate the model on iOS
In order to modify the content’s rotation, we need to connect the slider to an IBAction method and update the content’s rotation as follows:
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-(IBAction)sliderAction:(id)sender {
float rotZ = [self.mSliderRotZ value];
CATransform3D modelRotation = CATransform3DMakeRotation(rotZ*M_PI, 0, 0, 1);
[currentModel setRotation:modelRotation];
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