How to do the maths behind raycasting a FOV?

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#1

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Working on a neural network game and I am working on censes for the instances. First cense: Vision is generated by raycasts. Pray have FOV of 130 and preditors have a FOV of 50.

How would I go with raycasting every 5 degrees of the FOV? I’m not the best at math behind this.

Here’s a snippet of my script:

for c=1, rRange do
						local optimalangle = Vector3.new(0,entity.part.Orientation.Y,0) + Vector3.new(0,-(r/2)+(r*(c/rRange)),0)
						
				local optimalorigin = entity.part.Position + entity.part.CFrame.LookVector*(entity.part.Size.Z/2)
				local params = RaycastParams.new() params.FilterType = Enum.RaycastFilterType.Whitelist
						local ignore = {entity.part}
				if entity.entity == 'pray' then
					ignore[2] = preditorFolder
				else
					ignore[2] = prayFolder
				end
				params.FilterDescendantsInstances = ignore
				local newray = workspace:Raycast(optimalorigin,optimalangle,params)
				if newray then
							if newray.Distance <= 5 then
                              -- Proccessing is here
					end
				end


			end

local r = 50 if entity.entity == 'pray' then r = 130 end
					local rRange = r/5
#2

Just to be clear, you can’t do a “ray cast” that’s actually in the shape of a continous arc, only approximate it with a couple of individual “normal” ray casts.

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How to do that in code depends on how exactly you want your creatures’ senses to work. You’ve drawn the circular arc coming out of one face of a part, but what should happen if the creature ends up a bit rotated around it’s own Z axis? Should the arc still be “flat” in the world’s X/Z axes or should it follow the creature’s rotation?

Uhh I tried drawing it but it’s no easy xD

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Here’s an example of how rays can be cast in a circular arc:

function arcRayCast(origin, spreadAngle, maxRadius, numSegments, raycastParams)
    local angleStep = spreadAngle/numSegments
    local firstCFrame = origin * CFrame.Angles(0, -spreadAngle/2, 0)
    local results = {}
    for angle = -spreadAngle/2, spreadAngle/2, angleStep do
        local rayCFrame = firstCFrame * CFrame.Angles(0, angle, 0)
        local rayResult = game.Workspace:Raycast(rayCFrame.Position, rayCFrame.LookVector * maxRadius, raycastParams)
        if not result then continue end
        table.insert(results, rayResult)
    end
    
    return results
end

I think it’s right but I can’t test it ATM

3 Likes
#3

Very sorry for the almost year late reply :sweat_smile:, but thanks! Even though the project in question I’ve ended months ago your help is still useful!