CFrame
CFrame stands for Coordinate Frame. All objects inherited from BasePart have CFrame properties. These define where an object is, and its orientation (how it is rotated). The Position is part of a CFrame, along with a rotation matrix that defines how the object is oriented.
For example, in a place with a few bricks scattered about, put this in the command line:
The output will show something like this, though your numbers will be different if you place the brick in a different location:
The first 3 numbers from all that is the 3D position of an object, in this case
. The last 9 numbers make up a Rotation Matrix which describes which way the object is rotated, in this case
| 1 | 0 | 0 |
| 0 | 1 | 0 |
| 0 | 0 | 1 |
.
Using CFrames
CFrames are, since they tell you exactly where an object is and how it's rotated, very useful for making things move exactly where you want them. Let's take a look at how to use CFrames to your advantage.
Moving bricks around
Open up a new place with a part.
In the Command Line, type in this bit here and hit enter:
Workspace.Part.CFrame = CFrame.new(0, 50, 0)
You should see that the brick moved up a good distance, you may need to move the camera to see it. What you just did is change where the brick is, by changing it's CFrame. As you should know from the absolute beginner's guide to scripting, you changed the Part's CFrame property, or value by using the equal sign. You set Part.CFrame to a new CFrame, by using the CFrame.new constructor. You constructed a new CFrame using 3 different values. This told the Lua engine to set the brick's CFrame to 0, 50, 0, which set it's position to
, making the brick move to that position.
| CFrame you're changing | Set To | Position of where you want the brick |
| game.Workspace.Part.CFrame | = | CFrame.new(0, 50, 0) |
| The object named "Part" in Workspace | Move to here |
But wait! CFrames are not just useful for moving bricks around. When you change the CFrame property directly with a command, you can place bricks inside of other bricks. This is something that the Position property cannot do. You can also rotate bricks, but this is a little more complex.
Rotating bricks
At the bottom of this page you'll see a few tables that give you the different constructors for CFrame. You can see a bunch of new() commands, which all have different arguments inside of the function. This is because there are several different ways to create a CFrame. You can use just a position, like in the above example, or you can use the more complex ones.
In the case of rotating bricks the popular option is to actually use one of the operators instead of a Constructor.
| CFrame you're changing | Set To | Position of where you want the brick | With | Rotation of Brick |
| game.Workspace.Part.CFrame | = | CFrame.new(0, 50, 0) | * | CFrame.Angles(0, math.pi, 0) |
| The object named "Part" in Workspace | The same spot we just put the brick | Rotate this much |
What this does is take the object you want to rotate; creates a CFrame from it's current location; and uses the * operator to compose the rotation CFrame, which you created with CFrame.Angles
The CFrame.Angles constructor creates a CFrame that is just rotations. In the Moving Bricks part we created one that was just a position. Bricks use the CFrame for both rotation and position, which is what you create when you use the * operator. It takes the position CFrame and the Rotation CFrame, and combines them.
Radians
The numbers returned by CFrame.Angles() are radians (one radian is equal to the radius of the circle).
- math.pi/2 (A quarter turn, or 90 degrees)
- math.pi (A half turn, or 180 degrees)
- math.pi*2 (A full turn, or 360 degrees)
- math.pi + math.pi/2 (Three-quarters turn, or 270 degrees)
For more information on radians, see Radians.
CFraming more than one object
To CFrame more than one object we use the Get_(Method) to create a table of all selected objects, then we use a foor loop to CFrame all of the selected objects.
Used in the command bar:
for _,v in pairs(game.Selection:Get()) do v.CFrame = v.CFrame * CFrame.new(0, 0, 0) end
Constructors
These Constructors are used for creating CFrame values.
| Constructor | Description | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| CFrame.new() | Creates a blank identity CFrame | |||||||||
| CFrame.new(Vector3 position) | Creates CFrame from position. | |||||||||
| CFrame.new(Vector3 position, Vector3 point) | Creates CFrame from position, and looking at point. | |||||||||
| CFrame.new(number x, number y, number z) | Creates CFrame from position (x, y, z). | |||||||||
| CFrame.new(number x, number y, number z, number qx, number qy, number qz, number qw) | Creates CFrame from position (x, y, z) and quaternion (qx, qy, qz, qw). | |||||||||
| CFrame.new(x, y, z, R00, R01, R02, R10, R11, R12, R20, R21, R22) | Creates a CFrame at (x, y, z) with an orientation specified by the rotation matrix
| |||||||||
| CFrame.fromEulerAnglesXYZ(number rx, number ry, number rz) | Creates a rotated CFrame using angles (rx, ry, rz) in radians. | |||||||||
| CFrame.Angles(number rx, number ry, number rz) | Same function as fromEulerAnglesXYZ, shorter (preferred) name. Equivalent to:
CFrame.Angles(rx, 0, 0) * CFrame.Angles(0, ry, 0) * CFrame.Angles(0, 0, rz) This is only available in 2010+ clients. For older clients, use the equivalent fromEulerAnglesXYZ function. | |||||||||
| CFrame.fromAxisAngle(v, r) | Creates a rotated CFrame from a Unit Vector3 and a rotation in radians |
Properties
When you want to use just the position data from a CFrame you can use these properties of CFrames. Note that they are read only, meaning that you can use them, but you cannot change them. (ie: CFrame.x = 5 will not work, but a = CFrame.x will work)
| Property | Type | Description |
|---|---|---|
| CFrame.p | Vector3 | The 3D position of the CFrame |
| CFrame.x | number | the x-component of the Vector3 position |
| CFrame.y | number | the y-component of the Vector3 position |
| CFrame.z | number | the z-component of the Vector3 position |
| CFrame.lookVector | Vector3 | returns the facing direction (unit vector) |
Methods
| Member Function | Description |
|---|---|
| CFrame:inverse() | returns the inverse of this CFrame |
| CFrame:toWorldSpace(CFrame) | returns a CFrame transformed from Object to World coordinates. |
| CFrame:toObjectSpace(CFrame) | returns a CFrame transformed from World to Object coordinates. |
| CFrame:pointToWorldSpace(Vector3) | returns a Vector3 transformed from Object to World coordinates. |
| CFrame:pointToObjectSpace(Vector3) | returns a Vector3 transformed from World to Object coordinates. |
| CFrame:vectorToWorldSpace(Vector3) | returns a Vector3 rotated from Object to World coordinates. |
| CFrame:vectorToObjectSpace(Vector3) | returns a Vector3 rotated from World to Object coordinates. |
| CFrame:components() | returns the CFrame values: x, y, z, R00, R01, R02, R10, R11, R12, R20, R21, R22 |
| CFrame:toEulerAnglesXYZ() | returns "best guess" angles that could be used to generate CFrame |
Operators
These operators are used for combining CFrames and Vector3s.
| Operator | Description |
|---|---|
| CFrame * CFrame | returns composition of two CFrames |
| CFrame * Vector3 | returns Vector3 transformed from Object to World coordinates |
| CFrame + Vector3 | returns CFrame translated (slid) by Vector3 |
| CFrame - Vector3 | returns CFrame translated (slid) by -Vector3 |
