Mouse over block in 3d world ?-> how to check that

[Slastraf]

For my towerdefense game I want to allow the player to place a turret into the 3d world with the mouse.

I dont understand how to send a raycast from the camera when you click somewhere in the 3d world.

For example if i want to place a block on the terrain by left clicking inside the game.

Also I dont know how raycasting in general works . a link for that should be enough.

 

thanks

Friedrich

[macklebee]

Camera Pick: http://www.leadwerks.com/werkspace/page/api-reference/_/camera/camerapick-r199

 

simple example:

window = Window:Create("example",0,0,800,600)

context = Context:Create(window)

world = World:Create()

camera = Camera:Create()

camera:SetPosition(0,6,0)

light = DirectionalLight:Create()

light:SetRotation(45,45,0)

terrain = Terrain:Create(128,true)

 

box = Model:Box()

box:SetPickMode(0)

box:SetColor(1,0.5,0,1)

 

camrot = camera:GetRotation()

gx=Math:Round(context:GetWidth()/2)

gy=Math:Round(context:GetHeight()/2)

move = 0

strafe = 0

 

while window:KeyDown(Key.Escape)==false do

if window:Closed() then break end

 

mpos = window:GetMousePosition()

dx = mpos.x - gx

dy = mpos.y - gy

camrot.x = camrot.x + dy / 10.0

camrot.y = camrot.y + dx / 10.0

camera:SetRotation(camrot)

window:SetMousePosition(gx,gy)

move = Math:Curve(((window:KeyDown(Key.W)and 1 or 0) - (window:KeyDown(Key.S) and 1 or 0)),move,10)

strafe = Math:Curve(((window:KeyDown(Key.D)and 1 or 0) - (window:KeyDown(Key.A) and 1 or 0)),strafe,10)

camera:Move(strafe,0,move)

 

if window:MouseHit(1) then

pickinfo = PickInfo()

if (camera:Pick(mpos.x,mpos.y,pickinfo,0,true)) then

box:SetPosition(pickinfo.position)

end

end

 

Time:Update()

world:Update()

world:Render()

context:Sync(true)

end

[Thirsty Panther]

I discuss camera pick info here.

 

http://www.leadwerks.com/werkspace/topic/13394-operation-wolf/