libGDX 设置旋转点 3D [英] libGDX set rotation point 3D

问题描述

我有两个对象基地和武器，我需要将武器的旋转点设置为基地的位置.

I have two objects base and weapon and I need to set rotate point of weapon to position of base.

public Test(){
position1 = new Vector3(0,0,0);
baseModel = modelLoader.loadModel(Gdx.files.getFileHandle("data/models/tower/bases/base1.g3db", FileType.Internal));
        base = new Base(baseModel, position1);

        position2 = new Vector3(3,10,5);

        weaponModel = modelLoader.loadModel(Gdx.files.getFileHandle("data/models/tower/weapons/weapon2.g3db", FileType.Internal));
        weapon = new Weapon(weaponModel, position2);
}

这里是更新方法

public void update(float delta){

        weapon.transform.rotate(0, 1, 0, 45*(delta/2));
        base.transform.rotate(0, 1, 0, 45*(delta/2));
}

谢谢您的回答

推荐答案

围绕一个点旋转与平移到该点、旋转然后平移回相同.
所以这个过程包括3个步骤:

A rotation around a point is the same as translating to that point, rotating and then translating back.
So this process consists of 3 steps:

1. 翻译成rotationPoint，例如translate(3, 0, 0)
2. 围绕中心旋转(现在是 rotationPoint)，例如 rotate(0,1,0, 45*delta)
3. 平移回来(平移是相对于旋转的)，例如 translate(-3, 0, 0);

1. Translate to the rotationPoint, for example translate(3, 0, 0)
2. Rotate arround the center (which is now the rotationPoint), for example rotate(0,1,0, 45*delta)
3. Translate back (the translation is relative to the rotation), for example translate(-3, 0, 0);

在这种情况下，代码如下所示:

In this case the code then looks like this:

weapon.transform.translate(3, 0, 0).rotate(0,1,0, 45*delta).translate(-3, 0, 0); 

这篇关于libGDX 设置旋转点 3D的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！