获取与相机视图对齐的 3D 空间中的点

Question

我正在尝试使用 Frustum 来检测对象是否在屏幕的方形部分内（见下图）这是一个 UI 图像，用作目标框而不是 3D 对象。现在我可以让 Frustum 并绘制盒子工作，但只能朝一个方向看。我需要能够在相机转动时计算新点，但我不知道如何计算。下面的代码有点工作，但我需要偏移位置，以便在相机移动时它们与视图对齐。编辑：现在什么都不应该发生，但绘制框并使其工作。碰撞检测紧随其后。// Draw aimboxVector3 camPosOffset = camPos + cam.transform.forward * maxDistance;float frustumHeight = (2.0f * maxDistance * Mathf.Tan(cam.fieldOfView * 0.5f * Mathf.Deg2Rad));cubeVerts[0] = new Vector3(camPos.x, camPos.y, camPos.z);cubeVerts[1] = new Vector3(camPos.x, camPos.y, camPos.z);cubeVerts[2] = new Vector3(camPos.x, camPos.y, camPos.z);cubeVerts[3] = new Vector3(camPos.x, camPos.y, camPos.z);cubeVerts[4] = new Vector3(camPosOffset.x - frustumHeight, camPosOffset.y + frustumHeight, camPosOffset.z);cubeVerts[5] = new Vector3(camPosOffset.x + frustumHeight, camPosOffset.y + frustumHeight, camPosOffset.z);cubeVerts[6] = new Vector3(camPosOffset.x - frustumHeight, camPosOffset.y - frustumHeight, camPosOffset.z);cubeVerts[7] = new Vector3(camPosOffset.x + frustumHeight, camPosOffset.y - frustumHeight, camPosOffset.z);for (int i = 0; i < edges.Length; i += 2){    Debug.DrawLine(cubeVerts[edges[i]], cubeVerts[edges[i + 1]], Color.red);}

Answer 1

摆弄了将近两天后，我得到了我想要的东西。

        //Draw aimbox

    float frustumHeight = ((2.0f * maxDistance * Mathf.Tan(cam.fieldOfView/20 * 0.5f * Mathf.Deg2Rad))); //cam.fieldOfView/20, I divide by 20 because I only need a small square of the view

    cubeVerts[0] = cam.transform.position + cam.transform.forward * 25; //25 is the distance from the camera to the object it follows

    cubeVerts[1] = cam.transform.position + cam.transform.forward * 25;

    cubeVerts[2] = cam.transform.position + cam.transform.forward * 25;

    cubeVerts[3] = cam.transform.position + cam.transform.forward * 25;

    cubeVerts[4] = cam.transform.position + (cam.transform.right * -frustumHeight) + (cam.transform.up * frustumHeight) + (cam.transform.forward * maxDistance);

    cubeVerts[5] = cam.transform.position + (cam.transform.right * frustumHeight) + (cam.transform.up * frustumHeight) + (cam.transform.forward * maxDistance);

    cubeVerts[6] = cam.transform.position + (cam.transform.right * -frustumHeight) + (cam.transform.up * -frustumHeight) + (cam.transform.forward * maxDistance);

    cubeVerts[7] = cam.transform.position + (cam.transform.right * +frustumHeight) + (cam.transform.up * -frustumHeight) + (cam.transform.forward * maxDistance);

    for (int i = 0; i < edges.Length; i += 2)

    {

        Debug.DrawLine(cubeVerts[edges[i]], cubeVerts[edges[i + 1]], Color.red);

    }

这里改变的视锥体视图在任何给定时间跟随相机。

Answer 2

最简单的版本：使目标盒成为相机的子项。

替代解决方案，也对前 4 个顶点使用 camPosOffset，如下所示：

cubeVerts[0] = new Vector3(camPosOffset.x - frustumHeight, camPosOffset.y + frustumHeight, camPosOffset.z);

cubeVerts[1] = new Vector3(camPosOffset.x + frustumHeight, camPosOffset.y + frustumHeight, camPosOffset.z);

cubeVerts[2] = new Vector3(camPosOffset.x - frustumHeight, camPosOffset.y - frustumHeight, camPosOffset.z);

cubeVerts[3] = new Vector3(camPosOffset.x + frustumHeight, camPosOffset.y - frustumHeight, camPosOffset.z);

cubeVerts[4] = new Vector3(camPosOffset.x - frustumHeight, camPosOffset.y + frustumHeight, camPosOffset.z) + cam.forward * 3;

cubeVerts[5] = new Vector3(camPosOffset.x + frustumHeight, camPosOffset.y + frustumHeight, camPosOffset.z) + cam.forward * 3;

cubeVerts[6] = new Vector3(camPosOffset.x - frustumHeight, camPosOffset.y - frustumHeight, camPosOffset.z) + cam.forward * 3;

cubeVerts[7] = new Vector3(camPosOffset.x + frustumHeight, camPosOffset.y - frustumHeight, camPosOffset.z) + cam.forward * 3;