How to calculate the intersection world coordinates of the screen bounds by a vector going beyond the camera view to draw point?

Questions
1

I want show dots near at the screen(camera) bounds, which indicates objects outsdide of the camera fov. Similar to games where indicators show path to the location or NPC.

2

Camera view yellow square. And triangles are objects that locates outside of camera view.

camera
camera1280×1024 13 KB

3

Take a look at Frustum – three.js docs (threejs.org). Using traversal you can determine if an object is inside or outside the cameras view.

However, I would suggest you just used screen space (window) coordinates to determine if the triangle is within 0, 0, width, height

4

Triangles are indicators (or arrows) of the direction to which user will rotate camera with mouse to object outside the camera view, not actually objects in camera view. I didn’t see any methods Frustrum. I think i need method like projectAtNearPlane(object.position - camera.position) (or projectAtCameraDirectionPlane(object.position - camera.position) i don’t know) and this method will return sreen space coodinates where i will draw triangle.