Visuals

Visuals

The <visual> element specifies the shape of the geometry for rendering. It is a child element from <link> and a link can have multiple visual elements.

# Import the element creator
from pcg_gazebo.parsers.sdf import create_sdf_element

# The visual element is created with an empty geometry by default
visual = create_sdf_element('visual')
print(visual)

<visual name="visual">
  <geometry>
    <empty></empty>
  </geometry>
</visual>

# To see the optional elements, use the method reset()
visual.reset(with_optional_elements=True)
print(visual)

<visual name="visual">
  <pose frame="">0 0 0 0 0 0</pose>
  <geometry>
    <empty></empty>
  </geometry>
  <transparency>0</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

# Setting the parameters for the visual element

# Each visual in a link should have an unique name
visual.name = 'custom_visual'
# If cast_shadows is true, the geometry will cast shadows
visual.cast_shadows = True
# The transparency is a double in the range of [0, 1], 0 being opaque and 1 fully transparent
visual.transparency = 0.2
# Pose of the visual geometry with respect to a frame
visual.pose = [0, 0.2, 0, 0, 0, 0]
visual.pose.frame = 'base_link'

print(visual)

<visual name="custom_visual">
  <pose frame="base_link">0 0.2 0 0 0 0</pose>
  <geometry>
    <empty></empty>
  </geometry>
  <transparency>0.2</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

# Setting different geometries to the visual element
visual.geometry.box = create_sdf_element('box')
print(visual)
visual.geometry.sphere = create_sdf_element('sphere')
print(visual)
visual.geometry.cylinder = create_sdf_element('cylinder')
print(visual)
visual.geometry.plane = create_sdf_element('plane')
print(visual)
visual.geometry.mesh = create_sdf_element('mesh')
visual.geometry.mesh.reset(with_optional_elements=True)
print(visual)
visual.geometry.image = create_sdf_element('image')
print(visual)
visual.geometry.polyline = create_sdf_element('polyline')
print(visual)

<visual name="custom_visual">
  <pose frame="base_link">0 0.2 0 0 0 0</pose>
  <geometry>
    <box>
      <size>0 0 0</size>
    </box>
  </geometry>
  <transparency>0.2</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

<visual name="custom_visual">
  <pose frame="base_link">0 0.2 0 0 0 0</pose>
  <geometry>
    <sphere>
      <radius>0</radius>
    </sphere>
  </geometry>
  <transparency>0.2</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

<visual name="custom_visual">
  <pose frame="base_link">0 0.2 0 0 0 0</pose>
  <geometry>
    <cylinder>
      <radius>0</radius>
      <length>0</length>
    </cylinder>
  </geometry>
  <transparency>0.2</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

<visual name="custom_visual">
  <pose frame="base_link">0 0.2 0 0 0 0</pose>
  <geometry>
    <plane>
      <size>0 0</size>
      <normal>0 0 1</normal>
    </plane>
  </geometry>
  <transparency>0.2</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

<visual name="custom_visual">
  <pose frame="base_link">0 0.2 0 0 0 0</pose>
  <geometry>
    <mesh>
      <uri></uri>
      <submesh>
        <name>none</name>
        <center>0</center>
      </submesh>
      <scale>1 1 1</scale>
    </mesh>
  </geometry>
  <transparency>0.2</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

<visual name="custom_visual">
  <pose frame="base_link">0 0.2 0 0 0 0</pose>
  <geometry>
    <image>
      <uri></uri>
      <height>1</height>
      <granularity>1</granularity>
      <threshold>0</threshold>
      <scale>1</scale>
    </image>
  </geometry>
  <transparency>0.2</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

<visual name="custom_visual">
  <pose frame="base_link">0 0.2 0 0 0 0</pose>
  <geometry>
    <polyline>
      <height>1</height>
    </polyline>
  </geometry>
  <transparency>0.2</transparency>
  <cast_shadows>1</cast_shadows>
  <material>
    <specular>0.1 0.1 0.1 1</specular>
    <diffuse>0 0 0 1</diffuse>
    <shader type="pixel">
      <normal_map>default</normal_map>
    </shader>
    <emissive>0 0 0 1</emissive>
    <script>
      <uri>file://media/materials/scripts/gazebo.material</uri>
      <name>default</name>
    </script>
    <lighting>0</lighting>
    <ambient>0 0 0 1</ambient>
  </material>
</visual>

# Optional elements can also be created dynamically
visual = create_sdf_element('visual')
print(visual)

<visual name="visual">
  <geometry>
    <empty></empty>
  </geometry>
</visual>

visual.cast_shadows = True
print(visual)

<visual name="visual">
  <geometry>
    <empty></empty>
  </geometry>
  <cast_shadows>1</cast_shadows>
</visual>

visual.pose = [0, 0.2, 0, 0, 0, 0]
print(visual)

<visual name="visual">
  <pose frame="">0 0.2 0 0 0 0</pose>
  <geometry>
    <empty></empty>
  </geometry>
  <cast_shadows>1</cast_shadows>
</visual>

# The geometry entity can be set with a dictionary with all the child parameters
visual.geometry.box = dict(size=[2, 3, 4])
print(visual)

<visual name="visual">
  <pose frame="">0 0.2 0 0 0 0</pose>
  <geometry>
    <box>
      <size>2 3 4</size>
    </box>
  </geometry>
  <cast_shadows>1</cast_shadows>
</visual>

# The pose, as other variables, can be set using a dictionary
# For SDF elements with no child elements, only values, the dictionary must always have a key 'value'
#      d = {value=[0, 0, 0, 0, 0, 0]}
# If the element contains attributes, as the attribute 'frame' in the element 'pose', there should be a key
# 'attributes' with a dictionary containing all the attributes
#      d = {value=[0, 0, 0, 0, 0, 0], attributes=dict(frame='new_frame')}
visual.pose = {'value': [0, 0.2, 0, 0, 0, 0], 'attributes': {'frame': 'new_frame'}}
print(visual)

<visual name="visual">
  <pose frame="new_frame">0 0.2 0 0 0 0</pose>
  <geometry>
    <box>
      <size>2 3 4</size>
    </box>
  </geometry>
  <cast_shadows>1</cast_shadows>
</visual>