The Structure of Tangent and Binormal Properties

 
 
 

Tangents and binormals are each stored in a color at vertices (CAV) property, appropriately named Tangents and Binormals. Each CAV has its own operator stack. When you create tangents or binormals, a TangentOp2 operator generates the data. A Vertex Color Property Generator creates and updates the CAV and the Vertex Color Change Datatype operator sets the data type used for encoding the tangent and binormal data. Like other elements with operator stacks, you can freeze tangents and binormals to discard their history and simplify your scene data.

As soon as a tangent or binormal property is created, you can access it from the explorer, where it's available under the object's Clusters > Texture_Coordinates_AUTO node. Apart from the actual data being generated and stored, tangent and binormal properties have the same node structure.

A

Tangents

Binormals

Tangents and binormals are stored in color at vertices (CAV) properties named by default Tangents or Binormals according to the data that is being stored. These CAVs are also used for displaying the tangents and binormals in 3D views. See the Vertex Color Property Editor [Properties Reference].

If you rename the CAV, you will have to update any references to it by picking the CAV again in the Tangent Property Editor or the Binormal Property Editor [Properties Reference].

B

TangentOp2

TangentOp2

The TangentOp2 operator reads from the texture projection and computes the tangents or binormals at every vertex and stores them in a color at vertices (CAV) property. The same operator is used to generate both tangents and binormals.

You can also control the state of the operator and smooth any artifacts in the map using the Tangent Operator (TangentOp2) Property Editor [Properties Reference].

C

Vertex Color Change Datatype

Vertex Color Change Datatype

Sets the data type used to store the tangents and binormals. By default, tangent and binormal data is written as unclamped floating-point color values. The following options are available:

  • Float (4 bytes): The TangentOp2 operator writes to unclamped floating-point color values. True tangent data is encoded in the vertex color property. This is the default.

  • Short (2 bytes): The TangentOp2 operator uses a short integer to store the color values between 0 and 65535, interpreted as a value in the range [0, 1].

For more information, see Setting the Data Type for Tangents and Binormals.

D

Vertex Color Property Generator

Vertex Color Property Generator

The operator that generates and updates the color at vertices (CAV) property that stores the tangents and binormals.

E

Texture_ProjectionTextcoord

Texture_Projection Textcoord

The texture projection that generates the texture coordinates that are used by the TangentOp2 operator to create tangents and binormals. The name of the texture projection varies depending on which type of projection was applied.

F

TangentData

BinormalData

Holds the name of the color at vertices (CAV) property associated to the TangentOp2 operator.

This node acts as a tracking mechanism so that tangent and binormal properties do not compete for the same color at vertices property (overwriting each other every time the TangentOp2 operator re-evaluates the data).

Note: It is recommended that you do not modify any of the options in this property editor.

G

Tangent

Binormal

The property that specifies which color at vertices property (CAV) stores the tangents or binormals, and which texture projection to use.

If you rename the CAV property, you can reconnect to it using the Tangent Property Editor or the Binormal Property Editor [Properties Reference].