Game Development Reference
FIG 3.1 Spacewar!
sprites are dealt with by placing a texture representing the graphic element
over a plane game object. The plane is then moved around the screen to
create an animation. Both the rocket ship and the planet each have its own
materials representing the different images.
The more materials used in a game, the less efficiently it will run. This is
closely related to the way in which the power of two images is processed.
In the case of Unity, each material adds extra load inside each game
loop. This load is called a draw call . A draw call occurs when rendering
commands are processed by the computer's graphics processor. Each
material used equals one draw call. Therefore, if you have 100 materials it
will cost you 100 draw calls.
Unity Hands On
Investigating Draw Calls
Step 1. Create a new Project in Unity.
Step 2. Add two planes to the Scene.
Step 3. Position the camera so that the planes are visible in the Game.
Step 4. Click the Stats button in the top right of the Game tab. Note
that the number of draw calls is currently 1.