7.3.4 Environment structure

7.3.4.1 General

The environment consists of the terrain, buildings, objects, and traffic areas, for example roads. It also includes all stationary traffic items, such as traffic signals, signs or lights.

The environment’s 3D geometry is structured according to the node structure defined in Model structure. The structure begins with a root node, which is the parent of all other nodes. If applicable, the origin of the root node should match that of the corresponding OpenDRIVE map. Children of the root node are terrain, environment objects and the road network. The latter is further detailed by its child nodes drivable area, sidewalks, roadmarks, road objects and signals.

An example environment asset is provided in the examples folder.

Groups with a local transform are indicated in the structure by a (T). This is only an indicator in the documentation and must not be contained in the actual node name.

7.3.4.2 Model structure

7.3.4.2.1 Structure overview

7.3.4.2.2 Grp_Root

The environment consists of the terrain, buildings, objects, and traffic areas, for example roads. It also includes all stationary traffic items, such as traffic signals, signs or lights.

If applicable, the origin of this inertial coordinate frame should match that of the corresponding OpenDRIVE map.

Table 55. Grp_Root
<Header>
Origin	Origin of the inertial coordinate frame, matching the inertial coordinate frame of an associated OpenDRIVE map (if available).
x-axis	Pointing to the right (east for maps with geographic reference).
y-axis	Pointing up (north for maps with geographic reference).
z-axis	Pointing out of the drawing plane (up for maps with geographic reference).

7.3.4.2.3 Grp_Terrain

The terrain is characterized by the environment’s ground structure, such as hills, mountains, or flat territory, meaning, the landscape in general. It does not include local elevations like vegetation, buildings, or other human-made structures.

Figure 44. Grp_Terrain

7.3.4.2.4 Grp_Environment_Objects

An environment object consists of buildings, vegetation, and any other (stationary) object of the surrounding. An environment object causes a local elevation or other additions in the terrain.

Figure 45. Grp_Environment_Objects

7.3.4.2.5 Grp_Buildings

A building is a human-made structure and includes houses, towers, or skyscrapers.

Figure 46. Grp_Buildings

7.3.4.2.6 Grp_Vegetation

The vegetation includes all organic growths or plants that are part of the landscape. Vegetation can grow on the terrain or on human-made structures, for example between roads and buildings.

Figure 47. Grp_Vegetation

7.3.4.2.7 Grp_Road_Network

The road network is the entirety of a road. It includes the drivable area, sidewalks, and any other traffic objects, such as traffic signals, signs, or traffic lights.

Figure 48. Grp_Road_Network

7.3.4.2.8 Grp_Drivable_Area

The drivable area is a traffic space that is dedicated to vehicles. It is the surface part of the road structure on which vehicles drive and includes lanes and parking areas. The drivable area for ASAM OpenMATERIAL is comparable to the scope of the ASAM OpenDRIVE standard for on-road use cases.

Figure 49. Grp_Drivable_Area

7.3.4.2.9 Grp_Sidewalks

A sidewalk is a traffic space that is dedicated to pedestrians and sometimes cyclists. They are usually adjacent to the drivable area.

Figure 50. Grp_Sidewalks

7.3.4.2.10 Grp_Road_Marks

A road mark includes any markings on the road and traffic spaces.

Figure 51. Grp_Road_Marks

7.3.4.2.11 Grp_Road_Objects

A road object includes all other objects on or nearby the road, excluding signals.

Figure 52. Grp_Road_Objects

7.3.4.2.12 Grp_Signals

A signal in traffic is a visual sign used to control the flow of traffic. A traffic signal can be both a sign and a light. Signals describe the relevant area or volume of a traffic signal only. Posts and gantries are considered road objects.

Figure 53. Grp_Signals

7.3.4.2.13 Grp_Sign_<signal_idx> (T)

Traffic signs belong to traffic signals. They are indexed using a <signal_index>. The <signal_index> can be taken over from ASAM OpenDRIVE or ASAM OSI. If no predefined indices exist, they can be generated by iterating over all signals from (0,…,n). The indices are used for both traffic signs and traffic lights. A traffic sign cannot have the same index as a traffic light in a single environment.

Figure 54. Grp_Sign_<signal_idx>

Table 56. Grp_Sign
<Header>
Origin	Geometric center of the signs face.
x-axis	Concentric and coaxial to the surface normal of the sign face.
y-axis	Completes the right-handed coordinate system.
z-axis	Perpendicular to the x-axis, pointing vertically upwards.

7.3.4.2.14 Grp_Traffic_Light_<signal_idx> (T)

Traffic lights belong to traffic signals. They show temporary changes in illumination. The <signal_index> can be taken over from ASAM OpenDRIVE or ASAM OSI. If no predefined indices exist, they can be generated by iterating over all signals from (0,…,n). The indices are used for both traffic signs and traffic lights. A traffic light cannot have the same index as a traffic sign in a single environment.

Figure 55. Grp_Traffic_Light_<signal_idx>

Table 57. Grp_Traffic_Light
<Header>
Origin	Geometric center of the traffic light signal area surface.
x-axis	Concentric and coaxial to the surface normal of the signal area surface.
y-axis	Completes the right-handed coordinate system.
z-axis	Perpendicular to the x-axis, pointing vertically upwards.