Contents
How are units stored in a spatial partition?
Now, superimpose a grid of fixed-size squares onto it like a sheet of graph paper. Instead of storing our units in a single array, we put them in the cells of this grid. Each cell stores the list of units whose positions are within that cell’s boundary.
How are the edges of a cell partitioned?
The edges can be curved or straight, must be connected, and must belong to the same part as the cell to be partitioned. In addition, the patch must pass completely through the cell. Choose from the following methods to define the patch:
How is the cutting plane used to partition a cell?
Select an edge and a point along the edge; the cutting plane will be normal to the edge at the selected point, as shown in Figure 3 . Figure 3. Defining the cutting plane with an edge and a point. For detailed instructions, see Using the cutting plane method to partition cells .
How to partition a cell using an extension of a face?
Partitioning a cell using an extension of a face. Partition a cell by sweeping selected edges (that form the sweep profile) along a selected path (known as the sweep path). You can select any number of edges to be swept, although all the edges must be connected, must lie on the same plane, and must belong to the same part instance.
Why do some games have multiple spatial partitions?
Sophisticated games often have multiple spatial partitions for different kinds of content. The basic requirements for this pattern are that you have a set of objects that each have some kind of position and that you are doing enough queries to find objects by location that your performance is suffering.
How are objects stored in a spatial data structure?
Store them in a spatial data structure that organizes the objects by their positions. This data structure lets you efficiently query for objects at or near a location . When an object’s position changes, update the spatial data structure so that it can continue to find the object.
When do you update the spatial data structure?
When an object’s position changes, update the spatial data structure so that it can continue to find the object. This is a common pattern for storing both live, moving game objects and also the static art and geometry of the game world.