How to make Rotate3dAnimation more smoother?

Question

In my app I am using Rotate3dAnimation to show a Google map. The code is working fine, but the animation is not smooth, some lines are also visible while rotating the view.

Answer 1

One option for (non-OpenGL) 3d animation effects on Android is to implement the animations in a ViewGroup's getChildStaticTransform method using the graphics.Camera and Matrix classes.

In broad terms it's done like this:

• Extend ViewGroup or a subclass thereof.

• In the constructors, set staticTransformationEnabled to true:

   setStaticTransformationsEnabled(true);
  

• Override the protected method getChildStaticTransformation(View view, Transformation t).

• In getChildStaticTransformation, use graphics.Camera to rotate the View as per your picture.

• Get the camera's matrix and adjust it to center the camera position on the view.

For example, this is how a 3d translation effect is done in the 3d carousel by Igor Kushnarev:

protected boolean getChildStaticTransformation(View child, Transformation transformation) {
   //...
    // Center of the item
    float centerX = (float)child.getWidth()/2, centerY = (float)child.getHeight()/2;

    // Save camera
    mCamera.save();

    // Translate the item to it's coordinates
    final Matrix matrix = transformation.getMatrix();
    mCamera.translate(((CarouselImageView)child).getX(), 
            ((CarouselImageView)child).getY(), 
            ((CarouselImageView)child).getZ());

    // Get the camera's matric and position the item
    mCamera.getMatrix(matrix);
    matrix.preTranslate(-centerX, -centerY);
    matrix.postTranslate(centerX, centerY);

    // Restore camera
    mCamera.restore();      

    return true;
 }    

Here are some more code examples on how to use graphics.Camera and Matrixin getChildStaticTransformation:

• ViewPager3d by Inovex. This project is interesting because if you run it as is, the 3d animation is not smooth (on a Galaxy S2). Hoverever, if you strip it of the non-camera/matrix overscroll animations but keep the getChildStaticTransformation 3d effects done with camera and matrix, the 3d effects are smooth.

• CoverFlow by Neil Davies.