RDC_Simulation/docs/blender_models.md

Blender Models in Gazebo

Import 3D models from Blender into the ARG simulation.

Workflow

Blender (.blend) → Export COLLADA (.dae) → Gazebo Model → World

Step 1: Create Model in Blender

1. Create your 3D model
2. Apply all transforms: Ctrl+A → All Transforms
3. Set origin to geometry center

Step 2: Export from Blender

1. File → Export → COLLADA (.dae)
2. Settings:
   • Selection Only (if needed)
   • Include Armatures: OFF
   • Include Animations: OFF
   • Triangulate: ON
3. Save as model.dae

Step 3: Create Gazebo Model

gazebo/models/my_model/
├── model.config
├── model.sdf
├── meshes/
│   └── model.dae
└── materials/
    └── textures/
        └── texture.png

model.config

<?xml version="1.0"?>
<model>
  <name>My Model</name>
  <version>1.0</version>
  <sdf version="1.9">model.sdf</sdf>
  <description>Custom Blender model</description>
</model>

model.sdf

<?xml version="1.0"?>
<sdf version="1.9">
  <model name="my_model">
    <static>true</static>
    <link name="link">
      <collision name="collision">
        <geometry>
          <mesh>
            <uri>meshes/model.dae</uri>
            <scale>1 1 1</scale>
          </mesh>
        </geometry>
      </collision>
      <visual name="visual">
        <geometry>
          <mesh>
            <uri>meshes/model.dae</uri>
            <scale>1 1 1</scale>
          </mesh>
        </geometry>
      </visual>
    </link>
  </model>
</sdf>

Step 4: Add to World

<include>
  <uri>model://my_model</uri>
  <name>my_model_instance</name>
  <pose>5 3 0 0 0 0</pose>
</include>

Step 5: Set Model Path

export GZ_SIM_RESOURCE_PATH=$PWD/gazebo/models:$GZ_SIM_RESOURCE_PATH

Common Issues

Model Not Found

export GZ_SIM_RESOURCE_PATH=/full/path/to/gazebo/models:$GZ_SIM_RESOURCE_PATH

Scale Wrong

In Blender, check unit settings: Properties → Scene → Units

Adjust in SDF:

<scale>0.01 0.01 0.01</scale>

Textures Not Showing

Put textures in materials/textures/ and reference in DAE file.

Or add material in SDF:

<visual name="visual">
  <geometry>
    <mesh><uri>meshes/model.dae</uri></mesh>
  </geometry>
  <material>
    <diffuse>0.8 0.2 0.2 1</diffuse>
  </material>
</visual>

Model Orientation Wrong

Blender uses Z-up, Gazebo uses Z-up. Should match.

If rotated, fix in Blender or use pose:

<pose>0 0 0 1.5708 0 0</pose>

Simplified Collision

For complex meshes, use simple collision:

<collision name="collision">
  <geometry>
    <box><size>2 2 3</size></box>
  </geometry>
</collision>
<visual name="visual">
  <geometry>
    <mesh><uri>meshes/complex_model.dae</uri></mesh>
  </geometry>
</visual>

Template

Copy the template:

cp -r gazebo/models/custom_object gazebo/models/my_model

Then:

1. Edit model.config with your name
2. Edit model.sdf with your model name
3. Put your model.dae in meshes/

Test Model

gz sim -v4 gazebo/worlds/custom_landing.sdf