Point4d Structure 
The W (fourth) dimension is often considered the weight of the point as seen in 3D space.
Namespace: Rhino.Geometry
The Point4d type exposes the following members.
Name  Description  

Point4d(Point3d) 
Initializes a new instance of the Point4d class from the coordinates of a point.
 
Point4d(Point4d) 
Initializes a new point by copying coordinates from another point.
 
Point4d(Double, Double, Double, Double) 
Initializes a new instance of the Point4d class based on coordinates.

Name  Description  

IsValid 
Returns an indication regarding the validity of this point.
 
Unset 
Gets the value of a point with all coordinates set as RhinoMath.UnsetValue.
 
W 
Gets or sets the W (fourth) coordinate or weight of this point.
 
X 
Gets or sets the X (first) coordinate of this point.
 
Y 
Gets or sets the Y (second) coordinate of this point.
 
Z 
Gets or sets the Z (third) coordinate of this point.

Name  Description  

Add 
Sums two Point4d together.
(Provided for languages that do not support operator overloading. You can use the + operator otherwise)  
EpsilonEquals 
Check that all values in other are within epsilon of the values in this
 
Equals(Object) 
Determines whether the specified System.Object is Point4d and has same coordinates as the present point.
(Overrides ValueTypeEquals(Object).)  
Equals(Point4d) 
Determines whether the specified point has same value as the present point.
 
GetHashCode 
Computes the hash code for the present point.
(Overrides ValueTypeGetHashCode.)  
GetType  (Inherited from Object.)  
Multiply 
Multiplies a point by a number.
(Provided for languages that do not support operator overloading. You can use the * operator otherwise)  
Subtract 
Subtracts the second point from the first point.
(Provided for languages that do not support operator overloading. You can use the  operator otherwise)  
ToString  (Inherited from ValueType.)  
Transform 
Transforms the present point in place. The transformation matrix acts on the left of the point. i.e.,
result = transformation*point 
Name  Description  

Addition 
Sums two Point4d together.
 
Equality 
Determines whether two Point4d have equal values.
 
Inequality 
Determines whether two Point4d have different values.
 
Multiply(Point4d, Point4d) 
Multiplies two Point4d together, returning the dot (internal) product of the two.
This is not the cross product.
 
Multiply(Point4d, Double) 
Multiplies a point by a number.
 
Subtraction 
Subtracts the second point from the first point.
