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RGB Camera sensor

Don't forget

add sensor plugin to world
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<plugin
  filename="gz-sim-sensors-system"
  name="gz::sim::systems::Sensors">
  <render_engine>ogre2</render_engine>
</plugin>

RGB Camera

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<sensor name="camera" type="camera">
    <pose> 0 0 0 0 0 0 </pose>
    <visualize>true</visualize>
    <update_rate>10</update_rate>
    <camera>
        <camera_info_topic>camera/camera_info</camera_info_topic>
        <horizontal_fov>1.089</horizontal_fov>
        <image>
            <format>R8G8B8</format>
            <width>640</width>
            <height>480</height>
        </image>
        <clip>
            <near>0.05</near>
            <far>8.0</far>
        </clip>
    </camera>
    <topic>camera/image_raw</topic>
    <gz_frame_id>camera_link_optical</gz_frame_id>
</sensor>

Demo:

World with camera 
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<?xml version="1.0" ?>

<sdf version="1.6">
  <world name="empty">
    <physics name="1ms" type="ignored">
      <max_step_size>0.001</max_step_size>
      <real_time_factor>1.0</real_time_factor>
    </physics>
    <plugin
      filename="gz-sim-physics-system"
      name="gz::sim::systems::Physics">
    </plugin>
    <plugin
      filename="gz-sim-user-commands-system"
      name="gz::sim::systems::UserCommands">
    </plugin>
    <plugin
      filename="gz-sim-scene-broadcaster-system"
      name="gz::sim::systems::SceneBroadcaster">
    </plugin>
    <plugin
      filename="gz-sim-contact-system"
      name="gz::sim::systems::Contact">
    </plugin>
 <plugin
      filename="gz-sim-sensors-system"
      name="gz::sim::systems::Sensors">
      <render_engine>ogre2</render_engine>
    </plugin>
    <light type="directional" name="sun">
      <cast_shadows>true</cast_shadows>
      <pose>0 0 10 0 0 0</pose>
      <diffuse>0.8 0.8 0.8 1</diffuse>
      <specular>0.2 0.2 0.2 1</specular>
      <attenuation>
        <range>1000</range>
        <constant>0.9</constant>
        <linear>0.01</linear>
        <quadratic>0.001</quadratic>
      </attenuation>
      <direction>-0.5 0.1 -0.9</direction>
    </light>

    <model name="ground_plane">
      <static>true</static>
      <link name="link">
        <collision name="collision">
          <geometry>
            <plane>
              <normal>0 0 1</normal>
              <size>100 100</size>
            </plane>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <plane>
              <normal>0 0 1</normal>
              <size>100 100</size>
            </plane>
          </geometry>
          <material>
            <ambient>0.8 0.8 0.8 1</ambient>
            <diffuse>0.8 0.8 0.8 1</diffuse>
            <specular>0.8 0.8 0.8 1</specular>
          </material>
        </visual>
      </link>
    </model>

    <model name="box">
      <pose>0 -1 0.5 0 0 0</pose>
      <link name="box_link">
        <inertial>
          <inertia>
            <ixx>1</ixx>
            <ixy>0</ixy>
            <ixz>0</ixz>
            <iyy>1</iyy>
            <iyz>0</iyz>
            <izz>1</izz>
          </inertia>
          <mass>1.0</mass>
        </inertial>
        <collision name="box_collision">
          <geometry>
            <box>
              <size>1 1 1</size>
            </box>
          </geometry>
        </collision>

        <visual name="box_visual">
          <geometry>
            <box>
              <size>1 1 1</size>
            </box>
          </geometry>
          <material>
            <ambient>1 0 0 1</ambient>
            <diffuse>1 0 0 1</diffuse>
            <specular>1 0 0 1</specular>
          </material>
        </visual>
      </link>
    </model>

    <!-- camera -->
    <model name="camera">
      <pose>4 0 1.0 0 0.0 3.14</pose>
      <link name="link">
        <pose>0.05 0.05 0.05 0 0 0</pose>
        <inertial>
          <mass>0.1</mass>
          <inertia>
            <ixx>0.000166667</ixx>
            <iyy>0.000166667</iyy>
            <izz>0.000166667</izz>
          </inertia>
        </inertial>
        <collision name="collision">
          <geometry>
            <box>
              <size>0.1 0.1 0.1</size>
            </box>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <box>
              <size>0.1 0.1 0.1</size>
            </box>
          </geometry>
        </visual>
        <sensor name="camera" type="camera">
          <camera>
            <horizontal_fov>1.047</horizontal_fov>
            <image>
              <width>320</width>
              <height>240</height>
            </image>
            <clip>
              <near>0.1</near>
              <far>100</far>
            </clip>
          </camera>
          <always_on>1</always_on>
          <update_rate>30</update_rate>
          <visualize>true</visualize>
          <topic>camera</topic>
        </sensor>
      </link>
    </model>
  </world>
</sdf>

alt text

Add image display

Demo: Simple code to view the image using opencv and gz-transport

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import numpy as np
import cv2
import time

from gz.transport13 import Node
from gz.msgs10.image_pb2 import Image

def on_image(msg: Image):
    # Get image size
    width = msg.width
    height = msg.height

    # Convert raw bytes to numpy
    img = np.frombuffer(msg.data, dtype=np.uint8)

    # Most Gazebo cameras use RGB8
    img = img.reshape((height, width, 3))

    # Convert RGB → BGR for OpenCV
    img = cv2.cvtColor(img, cv2.COLOR_RGB2BGR)

    # Show image
    cv2.imshow("Gazebo Camera", img)
    cv2.waitKey(1)

node = Node()

ok = node.subscribe(Image, "/camera", on_image)
if not ok:
    raise RuntimeError("Failed to subscribe")

print("Listening to camera...")

# Keep program alive
while True:
    time.sleep(1)