Visualizing with the 3D scene

The 3D SCENE tab renders your machine in an interactive 3D view: the frames of every component, the geometry attached to them, point clouds from depth cameras, and any custom visuals a module publishes while the machine runs. It turns configuration you would otherwise read as JSON numbers into a picture you can inspect, so you can confirm a gripper sits where the arm expects it or watch a motion plan against the obstacles around it.

This page describes what the scene shows, where each element comes from, and how the scene stays current. For the tab’s panels, navigation, and settings, see the 3D scene tab reference.

What the scene renders

The scene draws four kinds of element, each with its own appearance:

• Component frames render as sets of red, green, and blue coordinate axes, one per component, positioned by each frame’s translation and orientation.
• Geometries render as translucent shapes (a box, sphere, or capsule) at the frame they are attached to.
• Point clouds from depth cameras render as colored point sets.
• Custom visuals render as whatever a module draws them as: markers, arrows, lines, meshes, or extra geometries, published while the machine runs.

Where each element comes from

Every element in the scene traces back to one source. The World panel lists every entity in a tree rooted at the world frame, so you can select anything on screen and follow it back to the component or module that produced it.

The first three appear because they are part of the machine’s configuration, and the scene reads that configuration whenever you open the tab. Custom visuals appear only when a module publishes them.

Built-in content versus custom visuals

The distinction between the sources matters because it tells you where to make a change:

• Built-in content is the frame system and configured geometry. The scene shows it with no code. To change a frame’s position or a geometry’s shape, edit the component’s configuration.
• Custom visuals are everything a module computes or senses at runtime: a detection, a planned path, a sensor’s obstacle readings. The scene shows them only while the module publishes them. To change a custom visual, change the module’s code.

If an element looks wrong, this split tells you where to look: a misplaced frame or geometry is a configuration problem, while a missing or stale custom visual is a module problem.

How the scene stays current

Built-in content reflects your configuration and, when the machine is online, each component’s live pose. Custom visuals stay current a different way: a module publishes them to a world state store service, and the scene subscribes to that service’s stream of transform changes. As the module adds, updates, and removes transforms, the scene applies each change to the one affected visual instead of redrawing everything, so a busy scene keeps up as the underlying data changes.

To publish your own custom visuals this way, see Publish visuals from a module.

What’s next