X3DOM 自定义导航

Question

X3DOM 是否有实现自定义相机导航的正确方法？我想在用户拖动缩放滑块时进行缩放，而在用户在屏幕上拖动时进行平移。 X3DOM 是否有 API 用于调用 pan()、zoom() 或 rotate() 函数？

到目前为止，我能想到三种解决方法，但都不是理想的解决方案：

手动更改视点属性：

document.getElementById("the_viewpoint").setAttribute("orientation", "some numbers here");
固定视点，改变<transform>的position/rotation，包含整个3d世界
重新安排活动。例如，当用户滑动缩放滑块时，触发鼠标滚轮事件进行缩放。

Answer 1

看起来像this functionality was added fairly recently, but has yet to be properly documented

PR 包括这个例子：

var d = function(selector) { return document.querySelector(selector)}

x3dom.runtime.ready = function() {
    var x3d = d('x3d');
    var viewpoint = d('viewpoint');
    var x3dCanvas = x3d.runtime.canvas;

    var _onMouseWheel = x3dCanvas.onMouseWheel;

    x3dCanvas.onMouseWheel = function(event) {
        if(event.altKey) {
            var offset = .01
            var fov = parseFloat(viewpoint.getAttribute('fieldofview')) || 1.571;

            if(event.wheelDelta < 0) offset = -offset;
            fov = Math.min(2, Math.max(0, fov+offset));

            viewpoint.setAttribute('fieldofview', fov)

        } else {
            _onMouseWheel.call(this, event);
        }
    }

    x3dCanvas.canvas.removeEventListener('mousewheel', _onMouseWheel); // unable to unbind when handler is anonymous function 
    x3dCanvas.canvas.addEventListener('mousewheel', x3dCanvas.onMouseWheel);
}

X3DOM 自定义导航

X3DOM Custom Navigation

x3d

x3dom