How to check if an object (point 3) is within camera's FOV?
I want to check if the object is visible through a given camera.
Preferably if I could manually set a new FOV angle just for the test.
I found a way by doing a semi rendering from the viewport converting point3 data to x,y coordinates in view space, but this requires the camera to use the actual viewport :(
I'm also thinking of building a cone that would mimic the camera cone and check ray intersections with it, but I have to give the cone a height and make sure it encompases the entire scene :(
Does anyone know of a simpler way?
Comments
here is some code for checking if objects are within the view
Please note that it uses pivot.
you should make it use boundingbox instead, to make it more accurate.
fn isPointInFrustrum pointPos = (
thePos = pointPos * viewport.getTM()
screen_origin = mapScreenToView [0,0] (thePos.z) [renderWidth,renderHeight]
end_screen = mapScreenToView [renderWidth,renderHeight] thePos.z [renderWidth,renderHeight]
world_size = screen_origin-end_screen
x_aspect = renderWidth/(abs world_size.x)
y_aspect = renderHeight/(abs world_size.y)
screen_coords = point2 (x_aspect*(thePos.x-screen_origin.x)) (-(y_aspect*(thePos.y-screen_origin.y)))
(((screen_coords.x >= 0) AND (screen_coords.x < renderWidth)) AND ((screen_coords.y >= 0) AND (screen_coords.y < renderHeight)))
)
TheObjects = objects as Array
FoundObjects = #()
for i = 1 to TheObjects.count do
(
if (isPointInFrustrum (TheObjects[i].pos))do
(
appendIfUnique FoundObjects TheObjects[i]
)
)
for o = 1 to FoundObjects.count do
(
clearSelection()
select FoundObjects
)