The METHOD keyword in a 3D Road Data File is set to 3D. RDF 3D road data is only supported with FTire (not with Fiala, MF-Tyre or MF-Swift). Visualization of the road is possible only with the Car Toolkit simulation (RDF 3D road is not visualized in general Motion).
A 3D road property file basically consists of the following five data blocks. If the same block appears more than once during road visualization, an error is returned and the road cannot be viewed. Additional [OFFSET] and [REFSYS] blocks can modify position and orientation of the defined road (see sections below).
[HEADER] [UNITS] [MODEL] [NODES] [ELEMENTS]
NODES
The table below describes the parameters (Number of Nodes and Node ID) in the [NODES] block. These parameters should defined in the order shown:
Figure 6.67: NODES Block Keywords
| Keyword | Description | Dimension |
| NUMBER_OF_NODES | This defines the total node number used in the 3D patch. |
N/A (Integer) |
| Node ID x, y, z | This defines the ID of each node and its positon. |
N/A Position (Integer) (Real), (Real), (Real) |
Example of a NODES block:
[NODES] NUMBER_OF_NODES = 4 1 5000 -3000 0 2 5000 3000 0 3 -5000 -3000 0 4 -5000 3000 0
ELEMENTS
The table below describes the parameters (Number of Elements and Element definitions) in the [ELEMENTS] block. These parameters should defined in the order shown:
Figure 6.68: ELEMENTS Block Keywords
| Keyword | Description | Dimension |
| NUMBER_OF_ELEMENTS | This defines the total element number used in the 3D patch. |
N/A (Integer) |
| Node ID, Node ID, Node ID, mu | This defines the Node IDs comprising the element and the road friction correction factor (mu). A Node ID cannot be duplicated in a element. |
N/A, N/A, N/A N/A (Integer), (Integer), (Integer), (Real) |
Example of an ELEMENTS block:
[ELEMENTS] NUMBER_OF_ELEMENTS = 4 1 2 3 1.0 2 4 3 1.0 3 4 5 1.0 4 6 5 1.0
REFSYS
The position and orientation of the 3D road are specified using either a [REFSYS] or [OFFSET] block. If both blocks are present, the road is defined based on the parameters in the [OFFSET] block. Ansys recommends using only one (usually the [OFFSET]) block.
The table below describes the parameters in the [REFSYS] block. The offset and rotation angle of the 3D road are defined in this block.
Figure 6.69: REFSYS Block Keywords for Offset and Rotation of a 3D Road
| Keyword | Description | Dimension |
| OFFSET = X Y Z | This defines the X, Y, Z direction offset of the 3D road. |
Position (Real) (Real) (Real) |
| ROTATION_ANGLE_XY_PLANE | This defines the rotation angle in the xy plane about the z-axis of the 3D road. The rotation center is Road Reference Frame. |
Angle (Real) |
Example of a REFSYS block:
[REFSYS] OFFSET = -3000.0 0.0 0.0 ROTATION_ANGLE_XY_PLANE = 180.0
OFFSET
The table below describes the parameters in the [OFFSET] block. The offset and rotation angle of the 3D road are defined here. This block is similar to [REFSYS], but the method of defining the offset is little different and this block has higher priority than the [REFSYS] block.
Figure 6.70: OFFSET Block Keywords for Offset and Rotation of a 3D Road
| Keyword | Description | Dimension |
| X | This defines the X direction offset of the 3D road. |
Length (Real) |
| Y | This defines the Y direction offset of the 3D road. |
Length (Real) |
| Z | This defines the Z direction offset of the 3D road. |
Length (Real) |
| ROTATION_ANGLE_XY_PLANE | This defines the rotation angle in the xy plane about the z-axis of the 3D road. The rotation center is Road Reference Frame. |
Angle (Real) |
Example of an OFFSET block:
[OFFSET] X = -4000.0 Y = 5000.0 Z = -1000.0 ROTATION_ANGLE_XY_PLANE = 180.0