Libgdx-Tween引擎的模型旋转值不正确

Question

我正在尝试用libgdx中的通用tween引擎旋转一个3d ModelInstance。这是我的屏幕类：

public class WallpaperScreen implements Screen {
private PerspectiveCamera camera;
private ModelBatch modelBatch;
private Model modelBody, modelHead;
private ModelInstance bodyModelInstance, headModelInstance;
private Environment environment;
private TweenManager tweenManager;
@Override
public void show() {
    tweenManager = new TweenManager();
    Tween.registerAccessor(ModelInstance.class, new Accesor());
    camera = new PerspectiveCamera(75, Gdx.graphics.getWidth(),
            Gdx.graphics.getHeight());
    camera.position.set(-10f, 2f, 0f);
    camera.lookAt(0f, 0f, 0f);
    camera.near = 0.1f;
    camera.far = 300.0f;
    modelBatch = new ModelBatch();
    UBJsonReader jsonReader = new UBJsonReader();
    G3dModelLoader modelLoader = new G3dModelLoader(jsonReader);
    modelBody = modelLoader.loadModel(Gdx.files.getFileHandle(
            "data/IS3/IS3_body.g3db", FileType.Internal));
    modelHead = modelLoader.loadModel(Gdx.files.getFileHandle(
            "data/IS3/IS3_tur.g3db", FileType.Internal));
    bodyModelInstance = new ModelInstance(modelBody);
    headModelInstance = new ModelInstance(modelHead);
    bodyModelInstance.transform.rotate(0, 1, 0, -90);
    headModelInstance.transform.rotate(0, 1, 0, -90);
    environment = new Environment();
    environment.set(new ColorAttribute(ColorAttribute.AmbientLight, 1f, 1f,
            1f, 1.0f));
    Tween.to(bodyModelInstance, 0, 2).target(45).start(tweenManager);
    Tween.to(headModelInstance, 0, 2).target(45).start(tweenManager);
}
@Override
public void render(float delta) {
    Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(),
            Gdx.graphics.getHeight());
    Gdx.gl.glClearColor(0, 128, 255, 0);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);
    tweenManager.update(delta);
    camera.update();
    modelBatch.begin(camera);
    modelBatch.render(bodyModelInstance, environment);
    modelBatch.render(headModelInstance, environment);
    modelBatch.end();
}

这是我的TweenAcesor:

public class Accesor implements TweenAccessor<ModelInstance> {
private Quaternion quat = new Quaternion();
@Override
public int getValues(ModelInstance target, int tweenType,
        float[] returnValues) {
    quat = target.transform.getRotation(quat);
    returnValues[0] = quat.getAxisAngle(Vector3.Y);
    return 1;
}
@Override
public void setValues(ModelInstance target, int tweenType, float[] newValues) {
    target.transform.rotate(Vector3.Y, newValues[0]);
}

问题是，这些模型旋转得很快(它们在这2秒内旋转了360度(，我只需要它们在2秒内从Y轴上的0度缓慢旋转到45度，我在加速器上做错了什么？

Answer 1

Quaternion是无状态的吗？对于您的所有推文，只有一个Accesor实例。

target.transform.rotate(Vector3.Y, newValues[0]);是将旋转X度，还是将旋转X度。您每次调用都会慢慢增加到45度。你看到旋转越来越快了吗？也许你想要setToRotation。