Contents
What do you need to know about a scene graph?
A scene graph isn’t a complete game or simulation engine, although it may be one of the main components of such an engine; it’s primary focus is representation of your 3d worlds, and efficient rendering thereof. Physics models, collision detection and audio are left to other development libraries that a user will integrate with.
How often does the scene graph update in Java?
The service polls the queue three times per second, which is enough to have 20 pulses pass by and if the camera hasn’t updated in that time, I assume there’s no animation or user interaction going on. The result is that the animation is smooth and the system does as many scene graph updates as it can when it can.
How is the scene graph used in OpenGL?
The scene graph manages all the graphics for you, reducing what would be thousands of lines of OpenGL down to a few simple calls.
Which is the best way to rebuild a scene graph?
Variations on these techniques exist, and new methods can offer added benefits. One alternative is scene graph rebuilding, where the scene graph is rebuilt for each of the operations performed. This, however, can be very slow, but produces a highly optimised scene graph.
How does a traversal of a scene graph work?
A traversal generally consists of starting at some arbitrary node (often the root of the scene graph), applying the operation (s) (often the updating and rendering operations are applied one after the other), and recursively moving down the scene graph (tree) to the child nodes, until a leaf node is reached.
Why do Kart / Auto games have scene graphs?
Typically, kart/auto games will have a “tunnel” scene-graph because visually the player will see only things along the road, so you just have to check where he is on the road to retrieve all visible objects around in the “tunnel”. A scene graph is a way of organizing all objects in the environment.
Can a scene graph be a 2D screen divider?
It can be flat (like a 2D screen divider in 2 or 4), or it can be a tree (like binary tree or quadtree, or any other kind of tree) or any other sorting structure that limits the number of operations you have to execute to get some space-related informations.
How are physics engines used in Babylon.js?
Babylon.js has a plugin system for physics engines that enables the user to add physics interactions to the scene’s objects. Unlike the internal collision system, a physics engine calculates objects’ body dynamics and emulates “real-life” interactions between them.