Question

我使用OrthographicCamera和unproject功能将屏幕点转换为世界点。

一切正常，但有时#unproject方法会返回一些差不多好/期望值，但差不多，所以你会看到它作为屏幕/世界跳跃X像素/单位左右。

//screenX, screenY -> mouse position when wheel is scrolled

(...) <- calculate new world size because of zooming and set it up in viewport object

//calculate difference in world two points
//where mouse was before zooming and where mouse is after it,
//related to worldCoords, and apply it to camera:
Vector2 before = viewport.unproject(new Vector2(screenX, screenY));
camera.viewportWidth = viewport.getWorldWidth();
camera.viewportHeight = viewport.getWorldHeight();
camera.update();
Vector2 after = viewport.unproject(new Vector2(screenX, screenY));
camera.position.x -= after.x - before.x;
camera.position.y -= after.y - before.y;

这段代码只是将重点放在＆＃34;指向世界＆＃34;功能 - 缩放

编辑/解决方案？：

OrthographicCamera类中的方法更新：

@Override
    public void update (boolean updateFrustum) {
        projection.setToOrtho(zoom * -viewportWidth / 2, zoom * (viewportWidth / 2), zoom * -(viewportHeight / 2), zoom
            * viewportHeight / 2, near, far);
        view.setToLookAt(position, tmp.set(position).add(direction), up);
        combined.set(projection);
        Matrix4.mul(combined.val, view.val);

        if (updateFrustum) {
            invProjectionView.set(combined);
            Matrix4.inv(invProjectionView.val);
            frustum.update(invProjectionView);
        }
    }

看起来这条线是有罪的：

view.setToLookAt(position, tmp.set(position).add(direction), up);

您可以复制此方法的代码并创建自己的代码，不带它。我想这种方法只是小马车，很难找到。现在别人不得不深入了解setToLookAt中的真正原因。

LibGdx，viewport / camera #unproject有时（并非总是）返回错误的值

0 个答案: