# Understanding Scene Graphs and Graph Edges

So I'm trying to getting to grips with using Scene graphs and nodes in my code (game coding in C++) and I think I understand the basics of them and how they are used (and I can definitely see the benefits), but I'm coming across the term "Graph Edge" and I can't find any reading material explaining exactly what they are and how they fit in with Scene Graphs/trees/nodes in object hierarchy structures.

If anyone knows of any good material or has their own answer on what graph edges are and how they fit in (in use and implementation) that would be great.

Thanks

• "Graph" refers to a relationship of "nodes" and "edges", usually drawn as circles and connecting lines, respectively. An edge goes between exactly two nodes, and for a scene graph is usually "directed", meaning which end is at which node makes a difference. Nodes and edges can each hold some settings & information. Jan 28 '15 at 17:59

Be aware that with explicit nodes and implicit edges, a path across a graph might be node->node->node; this is compact. When both nodes and edges are explicit, the same path would be node->edge->node->edge->node. This latter form increases the number of memory jumps (the arrows) to get from first to last node, increasing the chance of a cache miss. So unless you explicitly need edges, just reference one node from another, keeping memory access tight.