Scenes and Entities

The Scene Graph and its Possibilities

Similar to many game engines and 3D applications, a scene in this software is created via a scene graph. All objects in the scene graph are called entities. There is a root entity and everything in the scene will have either the root entity or a descendant of it as its parent. Below most nodes it is possible to add new nodes. This is done by selecting the intended parent node and then clicking the Add Child button. It is also possible to rearrange nodes in the scene graph by clicking and dragging them.

All entities have a position, a rotation and a scale. The positions are in meters, the rotations are in degrees and the scale is unit less. Parent parameters are applied to child entities.

It is recommended to add multiple types of entities in a scene graph side by side, as siblings under a common parent (and not put them as children under children). The reason for this is that it is easier to control rotations and positions of side by side items.

It is recommended to take some time exploring the possibilities of what can be created by adding different types of entities and positioning them in 3D space.

Entity grouping and positioning

Content-less entities (simply called Entity in the Add Child menu) offers a way of organizing the scene graph. Because parent position, rotation and scale parameters are applied to children it is convenient to group some types of entities together in this way.

It is a good idea to group multiple 2D Videos and graphics entities that are intended to stay together under a common parent content-less Entity.

Another convenient use of content-less entities is when positioning items. By placing an entity that is to be positioned as the child of a content-less entity there are two rotation, position and scale nodes. The parent (a content-less entity) can position and rotate the child entity to the intended position. The child entity is then rotated in position using its rotation parameters. This can solve certain "gimbal lock" type issues, and in general makes positioning easier.