Isaac Sim Conventions
This section provides a reference for the units, representations, and coordinate conventions used within Omniverse Isaac Sim.
Default Units
Measurement |
Units |
Notes |
|---|---|---|
Length |
Meter |
|
Mass |
Kilogram |
|
Time |
Seconds |
|
Physics Time-Step |
Seconds |
Configurable by User. Default is 1/60. |
Force |
Newton |
|
Frequency |
Hertz |
|
Linear Drive Stiffness |
\(kg/s^2\) |
|
Angular Drive Stiffness |
\((kg*m^2)/(s^2*angle)\) |
|
Linear Drive Damping |
\(kg/s\) |
|
Angular Drive Damping |
\((kg*m^2)/(s*angle)\) |
|
Diagonal of Inetria |
\((kg*m^2)\) |
Default Rotation Representations
Quaternions
API |
Representation |
|---|---|
Isaac Sim Core |
(QW, QX, QY, QZ) |
USD |
(QW, QX, QY, QZ) |
PhysX |
(QX, QY, QZ, QW) |
Dynamic Control |
(QX, QY, QZ, QW) |
Angles
API |
Representation |
|---|---|
Isaac Sim Core |
Radians |
USD |
Degrees |
PhysX |
Radians |
Dynamic Control |
Radians |
Matrix Order
API |
Representation |
|---|---|
Isaac Sim Core |
Row Major |
USD |
Row Major |
World Axes
Omniverse Isaac Sim follows the right-handed coordinate conventions.
Direction |
Axis |
Notes |
|---|---|---|
Up |
+Z |
|
Forward |
+X |
Default Camera Axes
Direction |
Axis |
Notes |
|---|---|---|
Up |
+Y |
|
Forward |
-Z |
Note
Isaac Sim to ROS Conversion: To convert from Isaac Sim Camera Coordinates to ROS Camera Coordinates, rotate 180 degrees about the X-Axis.
Image Frames (Synthetic Data)
Coordinate |
Corner |
|---|---|
(0,0) |
Top Left |