How do i rotate a model?[unsolved]

player = game.Players.LocalPlayer
mouse = player:GetMouse()
x=1
y=1
z=1

function onKeyPress(inputObject, gameProcessedEvent)
	if inputObject.KeyCode == Enum.KeyCode.R then
		print'r' -- just here cause
		player.Character.short:FindFirstChild("Model"):SetPrimaryPartCFrame(
CFrame.new(x,y,z),CFrame.Angles(0,math.pi,0))
	end
end

game:GetService("UserInputService").InputBegan:connect(onKeyPress)

where short is the name of a message.

sadly, the above script does not work. It's supposed to rotate the model whenever i press r. But what happens is that the model moves a little bit lower, presumably to the y position of pi. So how do i have the model be rotated?

SetPrimaryPartCFrame doesn't take two arguments. You need to multiply your CFrames together to apply the rotation, like this:

player.Character.short:FindFirstChild("Model"):SetPrimaryPartCFrame( CFrame.new(x,y,z) * CFrame.Angles(0,math.pi,0) ) )

(Further reading on creating rotated CFrames)

What Dakota said is correct however you want to remove the x, y and z variables you created and do the following instead:

local model = player.Character.short:FindFirstChild("Model")
model:SetPrimaryPartCFrame(model.PrimaryPart.CFrame * CFrame.Angles(0,math.pi,0))

This sets the model to it's current CFrame + 180 degrees (math.pi).

If you want to rotate by 90 degrees you can do math.pi/2 or math.rad(90)

Here is how you would do it using the mouse:

local model = player.Character.short:FindFirstChild("Model")
model:SetPrimaryPartCFrame((model.PrimaryPart.CFrame - model.PrimaryPart.CFrame.p + mouse.Hit.p) * CFrame.Angles(0,math.pi,0))

You get the current CFrame of the model and minus it's position, add the mouses position and then rotate.