Papervision3D：使物体在移动相机时看起来静止

Question

我想让一个物体在移动相机时看起来保持在同一个地方。

我正在使用这个脚本 http://pv3d.org /2008/11/19/dragging-mouse-for-camera-orbit/ 使用鼠标拖动来绕对象旋转。但场景中有一个物体我想保持静止。我该如何做到这一点？

谢谢， 乔什

Answer 1

好的，我浏览了 Papervision 中的 Camera3D 源代码。这是轨道的实现：

            /**
             * Orbits the camera around the specified target. If no target is specified the 
             * camera's #target property is used. If this camera's #target property equals null
             * the camera orbits the origin (0, 0, 0).
             * 
             * @param       pitch   Rotation around X=axis (looking up or down).
             * @param       yaw             Rotation around Y-axis (looking left or right).
             * @param       useDegrees      Whether to use degrees for pitch and yaw (defaults to 'true').
             * @param       target  An optional target to orbit around.
             */ 
            public override function orbit(pitch:Number, yaw:Number, useDegrees:Boolean=true, target:DisplayObject3D=null):void
            {
                    target = target || _target;
                    target = target || DisplayObject3D.ZERO;

                    if(useDegrees)
                    {
                            pitch *= (Math.PI/180);
                            yaw *= (Math.PI/180);
                    }

                    // Number3D.sub
                    var dx                  :Number = target.world.n14 - this.x;
                    var dy                  :Number = target.world.n24 - this.y;
                    var dz                  :Number = target.world.n34 - this.z;

                    // Number3D.modulo
                    var distance    :Number = Math.sqrt(dx*dx+dy*dy+dz*dz);

                    // Rotations
                    var rx :Number = Math.cos(yaw) * Math.sin(pitch);
                    var rz :Number = Math.sin(yaw) * Math.sin(pitch);
                    var ry :Number = Math.cos(pitch);

                    // Move to specified location
                    this.x = target.world.n14 + (rx * distance);
                    this.y = target.world.n24 + (ry * distance);
                    this.z = target.world.n34 + (rz * distance);

                    this.lookAt(target);
            }

您可以将其实现为要保持静止的对象的辅助函数。我相信此函数中涉及的唯一相机特定代码是lookAt() 函数。

然后，您可以将其添加到 mouseMove 处理程序中的camera.orbit() 之前，并且它应该与您的相机保持静止。