Screen to Vector showing incorrect possitions

[gononono64]

Hey there,
I'm trying to setup a basic gamemode where players are in an isometric view. They can see their players running around a grid. What I am trying to do, and struggling a lot with, is to have a tile return its placement in a grid when a players mouse moves/hovers over it.
Ive checked the wiki for this and have attempted to do such a thing. However, I seem to be getting incorrect coords displacing by a few gmod vector points. Ive been working on this for quite a while and have no idea what the heck is going on.
This is my think function on client side for entity Tile:
function ENT:Think()
local pos = self:GetPos()
local tr = util.QuickTrace( LocalPlayer():EyePos(), gui.ScreenToVector( gui.MousePos() ), LocalPlayer() )
print( tr.HitPos )
print(pos)
 end

And this is how I changed local players view:
function MyCalcView( ply, pos, angles, fov )

local viewType = tostring(ply:GetPData("view"))

if viewType == "ISO" then

local view = {}
view.origin = Vector(-399, -400, 400)
view.angles = Angle(60, 45, 0)
view.fov = fov
view.drawviewer = true

return view

elseif viewType == "DEFAULT" then

end

end

hook.Add("CalcView", "MyCalcView", MyCalcView)
This is some of the output im getting
190.000000 -95.000000 -444.000000 -- odds are tile coord
-71.200233 -112.077797 -378.843933 -- evens are mouse to 3d pos
190.000000 -47.500000 -444.000000
-71.200233 -112.077797 -378.843933
190.000000 0.000000 -444.000000
-71.200233 -112.077797 -378.843933
190.000000 47.500000 -444.000000
-71.200233 -112.077797 -378.843933
190.000000 95.000000 -444.000000
-71.200233 -112.077797 -378.843933
190.000000 142.500000 -444.000000
-71.200233 -112.077797 -378.843933
190.000000 190.000000 -444.000000
-71.200233 -112.077797 -378.843933
190.000000 237.500000 -444.000000
-71.200233 -112.077797 -378.843933
which looks correct. But upon moving my mouse across the grid. the mouse pos only shifts by around 1 or so

Any ideas? I greatly appreciate any help you guys have for me. Thank you

[Bobblehead]

Try using the more generic function to get mouse position. (I forget the name but there's a link on the gui.ScreenToVector wiki page)
You can set your camera position, mouse pos, fov, etc.

[MPan1 banned]

util.AimVector

[gononono64]

Thank you so much for the help. I'm getting closer. I've since replaced it with this:
local ang = Angle(45, 45, 0 ) 
local aimVec = util.AimVector(ang, LocalPlayer():GetFOV() , gui.MouseX(), gui.MouseY(), ScrW(), ScrH())
print((aimVec * 1000) -  Vector( 449, 450, -200)) --added so easier to compare(vector is my cam pos)

Ive also updated my camera so its more isometric.
I couldn't use LocalPlayer:EyeAngles() so i replaced it with a local angle (same as the calcview angle). Also noted that i might be able to use renderangles or eyeangles. (seems to give same results)
Anyways, I'm getting values much closer than before but it seems my 0,0 position is off. I should be getting a value between 285 and -285 for both x and y axis.
But instead im getting:
bottom left: (-205, 256)
top left: (256, -205)
bottom right: (-143, -143)
top right (133, 133)

Like I said. close! But still slightly off. As I mentioned before My 0,0 pos is off aswell.
Any Ideas?

[Bobblehead]

vector:ToScreen() has problems if you don't do cam.Start3D() cam.End3D() before it. Maybe it's similar to that:
cam.Start3D()
cam.End3D()

local ang = Angle(45, 45, 0 )
local aimVec = util.AimVector(ang, LocalPlayer():GetFOV() , gui.MouseX(), gui.MouseY(), ScrW(), ScrH())
print((aimVec * 1000) - Vector( 449, 450, -200)) --added so easier to compare(vector is my cam pos)

[gononono64]

Didnt seem to do anything

[Bobblehead]

Good haha because I just realized I was having the same issue! :P

[gononono64]

Its still slightly off. I noticed the further away my tile the large the search area. I just turn the "20s" into a search offset variable and tweaked the number until it only selected 1 tile at the furthest point. However if someone has a solution for that i would be very happy to hear it as i may have to scale up my grid in the future.

[gononono64]

This is how i fixed the above:
function ENT:GetMouseTile()

    cam.Start3D()
    cam.End3D()

    local tilePos = self:GetPos()

    local posF = tilePos + (Vector(0, 25, 0))
    local toScreenPosF = posF:ToScreen()

    local posB = tilePos - (Vector(0, 25, 0))
    local toScreenPosB = posB:ToScreen()    

    local posR = tilePos + (Vector(25, 0, 0))
    local toScreenPosR = posR:ToScreen()

    local posL = tilePos - (Vector(25, 0, 0))
    local toScreenPosL = posL:ToScreen()

    if (gui.MouseX() >= (toScreenPosF.x )) and (gui.MouseX() <= (toScreenPosB.x))  then
        if (gui.MouseY() >= (toScreenPosR.y )) and (gui.MouseY() <= (toScreenPosL.y)) then
            self:SetColor(Color(0,255,0))

            return true
        else
            self:SetColor(Color(255,255,255))
            return false
        end

    else
        self:SetColor(Color(255,255,255))
        return false
    end
end

[Bobblehead]

That works well for entities with rectangular prism collision bounds, like cubes or boxes. Nice snippet.