为 Android 应用程序创建 3D 动画

Question

我需要根据用户在屏幕上滑动的速度创建 3D 翻转/旋转动画，我可以使用 ObjectAnimator 及其相关属性创建此动画，但我需要建议如何创建 3D上面的android中的动画。我还需要执行一些部分旋转的动画

虽然对于 android 我们可以使用 OPENGL，但是对于简单的动画 OPENGL 太重了，因为我们不是在设计真正的游戏。我参考了以下链接：

• https://2cupsoftech.wordpress.com/2012/09/18/3d-flip-between-two-view-or-viewgroup-on-android/
• http://www.inter-fuser.com/2009/08/android-animations-3d-flip.html

Answer 1

试试这个

MainActivity.java

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ButterKnife.bind(this);

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    ft.replace(R.id.layout_main, ExampleFragment.newInstance(ExampleFragment.NODIR));
    ft.commit();
}

ExampleFragment.java

public class ExampleFragment extends Fragment {

    @IntDef({NONE, FLIP})
    public @interface AnimationStyle {}
    public static final int NONE     = 0;
    public static final int FLIP     = 2;

    @IntDef({NODIR, UP, DOWN, LEFT, RIGHT})
    public @interface AnimationDirection {}
    public static final int NODIR = 0;
    public static final int UP    = 1;
    public static final int DOWN  = 2;
    public static final int LEFT  = 3;
    public static final int RIGHT = 4;

    private static final long DURATION = 500;

    @AnimationStyle
    private static int sAnimationStyle = FLIP;

    public static ExampleFragment newInstance(@AnimationDirection int direction) {
        ExampleFragment f = new ExampleFragment();
        f.setArguments(new Bundle());
        f.getArguments().putInt("direction", direction);
        return f;
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.content_anim, null);

        // For generating random Colors
        int color = Color.rgb((int) Math.floor(Math.random() * 128) + 64,
                (int) Math.floor(Math.random() * 128) + 64,
                (int) Math.floor(Math.random() * 128) + 64);
        view.setBackgroundColor(color);

        ButterKnife.bind(this, view);
        return view;
    }


@Override
public Animation onCreateAnimation(int transit, boolean enter, int nextAnim) {
    switch (sAnimationStyle) {
        case FLIP:
            switch (getArguments().getInt("direction")) {
                case UP:
                    return FlipAnimation.create(FlipAnimation.UP, enter, DURATION);
                case DOWN:
                    return FlipAnimation.create(FlipAnimation.DOWN, enter, DURATION);
                case LEFT:
                    return FlipAnimation.create(FlipAnimation.LEFT, enter, DURATION);
                case RIGHT:
                    return FlipAnimation.create(FlipAnimation.RIGHT, enter, DURATION);
            }
            break;
    }
    return null;
}


    @OnClick(R.id.buttonUp)
    void onButtonUp() {
        getArguments().putInt("direction", UP);
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        ft.replace(R.id.layout_main, ExampleFragment.newInstance(UP));
        ft.commit();
    }

    @OnClick(R.id.buttonDown)
    void onButtonDown() {
        getArguments().putInt("direction", DOWN);
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        ft.replace(R.id.layout_main, ExampleFragment.newInstance(DOWN));
        ft.commit();
    }

    @OnClick(R.id.buttonLeft)
    void onButtonLeft() {
        getArguments().putInt("direction", LEFT);
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        ft.replace(R.id.layout_main, ExampleFragment.newInstance(LEFT));
        ft.commit();
    }

    @OnClick(R.id.buttonRight)
    void onButtonRight() {
        getArguments().putInt("direction", RIGHT);
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        ft.replace(R.id.layout_main, ExampleFragment.newInstance(RIGHT));
        ft.commit();
    }
}

FlipAnimation.java

public class FlipAnimation extends ViewPropertyAnimation {

    @IntDef({UP, DOWN, LEFT, RIGHT})
    @interface Direction {}
    public static final int UP    = 1;
    public static final int DOWN  = 2;
    public static final int LEFT  = 3;
    public static final int RIGHT = 4;

    protected final @Direction int mDirection;
    protected final boolean mEnter;

    public static FlipAnimation create(@Direction int direction, boolean enter, long duration) {
        switch (direction) {
            case UP:
            case DOWN:
                return new VerticalFlipAnimation(direction, enter, duration);
            case LEFT:
            case RIGHT:
                return new HorizontalFlipAnimation(direction, enter, duration);
        }
        return null;
    }

    private FlipAnimation(@Direction int direction, boolean enter, long duration) {
        mDirection = direction;
        mEnter = enter;
        setDuration(duration);
    }

    private static class VerticalFlipAnimation extends FlipAnimation {

        public VerticalFlipAnimation(@Direction int direction, boolean enter, long duration) {
            super(direction, enter, duration);
        }

        @Override
        public void initialize(int width, int height, int parentWidth, int parentHeight) {
            super.initialize(width, height, parentWidth, parentHeight);
            mPivotX = width * 0.5f;
            mPivotY = (mEnter == (mDirection == UP)) ? 0.0f : height;
            mCameraZ = -height * 0.015f;
        }

        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            float value = mEnter ? (interpolatedTime - 1.0f) : interpolatedTime;
            if (mDirection == DOWN) value *= -1.0f;
            mRotationX = value * 180.0f;
            mTranslationY = -value * mHeight;

            super.applyTransformation(interpolatedTime, t);

            // Hide exiting view after half point.
            if (interpolatedTime >= 0.5f && !mEnter) {
                mAlpha = 0.0f;
            }
            applyTransformation(t);
        }
    }

    private static class HorizontalFlipAnimation extends FlipAnimation {

        public HorizontalFlipAnimation(@Direction int direction, boolean enter, long duration) {
            super(direction, enter, duration);
        }

        @Override
        public void initialize(int width, int height, int parentWidth, int parentHeight) {
            super.initialize(width, height, parentWidth, parentHeight);
            mPivotX = (mEnter == (mDirection == LEFT)) ? 0.0f : width;
            mPivotY = height * 0.5f;
            mCameraZ = -width * 0.015f;
        }

        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            float value = mEnter ? (interpolatedTime - 1.0f) : interpolatedTime;
            if (mDirection == RIGHT) value *= -1.0f;
            mRotationY = -value * 180.0f;
            mTranslationX = -value * mWidth;

            super.applyTransformation(interpolatedTime, t);

            // Hide exiting view after half point.
            if (interpolatedTime >= 0.5f && !mEnter) {
                mAlpha = 0.0f;
            }
            applyTransformation(t);
        }
    }
}

ViewPropertyAnimation.java

public class ViewPropertyAnimation extends Animation {

    private final Camera mCamera = new Camera();
    protected int mWidth  = 0;
    protected int mHeight = 0;
    protected float mAlpha = 1.0f;
    protected float mPivotX = 0.0f;
    protected float mPivotY = 0.0f;
    protected float mScaleX = 1.0f;
    protected float mScaleY = 1.0f;
    protected float mRotationX = 0.0f;
    protected float mRotationY = 0.0f;
    protected float mRotationZ = 0.0f;
    protected float mTranslationX = 0.0f;
    protected float mTranslationY = 0.0f;
    protected float mTranslationZ = 0.0f;
    protected float mCameraX = 0.0f;
    protected float mCameraY = 0.0f;
    protected float mCameraZ = -8.0f;

    private float mFromAlpha = -1.0f;
    private float mToAlpha   = -1.0f;

    public ViewPropertyAnimation fading(@FloatRange(from=0.0f,to=1.0f) float fromAlpha, @FloatRange(from=0.0f,to=1.0f) float toAlpha) {
        mFromAlpha = fromAlpha;
        mToAlpha = toAlpha;
        return this;
    }

    @Override
    public void initialize(int width, int height, int parentWidth, int parentHeight) {
        super.initialize(width, height, parentWidth, parentHeight);
        mWidth = width;
        mHeight = height;
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);
        if (mFromAlpha >= 0 && mToAlpha >= 0) {
            mAlpha = mFromAlpha + (mToAlpha - mFromAlpha) * interpolatedTime;
        }
    }

    protected void applyTransformation(Transformation t) {
        final Matrix m = t.getMatrix();
        final float w = mWidth;
        final float h = mHeight;
        final float pX = mPivotX;
        final float pY = mPivotY;

        final float rX = mRotationX;
        final float rY = mRotationY;
        final float rZ = mRotationZ;
        if ((rX != 0) || (rY != 0) || (rZ != 0)) {
            final Camera camera = mCamera;
            camera.save();
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR1) {
                camera.setLocation(mCameraX, mCameraY, mCameraZ);
            }
            if (mTranslationZ != 0) {
                camera.translate(0, 0, mTranslationZ);
            }
            camera.rotateX(rX);
            camera.rotateY(rY);
            camera.rotateZ(-rZ);
            camera.getMatrix(m);
            camera.restore();
            m.preTranslate(-pX, -pY);
            m.postTranslate(pX, pY);
        }

        final float sX = mScaleX;
        final float sY = mScaleY;
        if ((sX != 1.0f) || (sY != 1.0f)) {
            m.postScale(sX, sY);
            final float sPX = -(pX / w) * ((sX * w) - w);
            final float sPY = -(pY / h) * ((sY * h) - h);
            m.postTranslate(sPX, sPY);
        }

        m.postTranslate(mTranslationX, mTranslationY);

        t.setAlpha(mAlpha);
    }
}

Answer 2

其实你已经提到了：

基于用户在屏幕上滑动的速度的 3D 翻转/旋转动画

所以，我认为 Android Animation 不适合您的情况。但如果您有自定义视图方面的经验，android.graphics.Camera 中的类会帮助您。

首先，你需要声明

camera = new Camera();

然后覆盖 OnDraw 。

canvas.save();
Matrix matrix = new Matrix(); 
camera.save();
camera.rotateY(rotateAngle);
camera.getMatrix(matrix);
camera.restore();

mPaint.setColor(textBackgroundColor);
int centerX = diameter / 2;
int centerY = diameter / 2;
matrix.preTranslate(-centerX, -centerY);
matrix.postTranslate(centerX, centerY);
canvas.concat(matrix);
canvas.drawCircle(diameter / 2, diameter / 2, diameter / 2, mPaint);
canvas.restore();

现在您可以看到我们围绕 y 轴旋转了一个圆 rotateAngle 度数。您可以更改 rotateAngle 的值来调整角度。

你可以参考我最新的文章here，源码在github link。