World XML definition of VisualObject

Vehicles and obstacles blocks share common C++ mvsim::Simulable and mvsim::VisualObject interfaces that provide the common parameters below.

Note

The following parameters can appear in either the {vehicle,block} class definitions or in a particular instantiation block, depending on whether you want parameters to be common to all instances or not, respectively.

Repository of reusable 3D models

A list of 3D models, readily usable within MVSim, is maintained in this Git repository, which is accessible via HTTPS through this index. Refer to example worlds for case of use of these objects and vehicles.

Related to visual aspect

Under the <visual> </visual> tag group:

• model_uri: Path to 3D model file. Can be any file format supported by ASSIMP, like .dae, .stl, etc. If empty, the default visual aspect will be used.

• model_scale: (Default=1.0) Scale to apply to the 3D model.

• visual_scale: (Only for blocks) Per-instance override for the model scale. When specified in a <block> instance, this value overrides the model_scale defined in the <visual> section of the block class. This allows creating size variations of the same block class without defining new classes. If not specified or set to NaN, the block uses the model_scale from its visual definition.

• model_offset_x, model_offset_y , model_offset_z: (Default=0) Offset translation [meters].

• model_yaw, model_pitch, model_roll: (Default=0) Optional model rotation [degrees].

• model_color: (Default: white) For colorless files (e.g. *.stl), the color to use (see color formatting).

• model_cull_faces: (Default=``NONE``) Can be one of NONE | BACK | FRONT.

• model_split_size: (Default=0.0, disabled) Only required for semi-transparent meshes. Defines the size [meters] of auxiliary voxels used to split triangles and help sorting them by depth for correct rendering.

• show_bounding_box: (Default=``false``) Initial visibility of the object bounding box.

  Note

  The visual_scale parameter is only available for blocks, not vehicles. For vehicles, you must define separate vehicle classes with different model_scale values if you need size variations.

Example (block class with visual model):

<block:class name="tree">
  <visual>
    <model_uri>tree_model.dae</model_uri>
    <model_scale>1.0</model_scale>
    <model_offset_z>0.0</model_offset_z>
  </visual>
</block:class>

<!-- Instance 1: Default scale -->
<block class="tree" name="tree1">
  <init_pose>10 20 0</init_pose>
</block>

<!-- Instance 2: Half size -->
<block class="tree" name="tree2">
  <init_pose>15 25 0</init_pose>
  <visual_scale>0.5</visual_scale>
</block>

<!-- Instance 3: Double size -->
<block class="tree" name="tree3">
  <init_pose>20 30 0</init_pose>
  <visual_scale>2.0</visual_scale>
</block>