From scene to screen.
WHAT THE RENDERER DOES EACH FRAME
Determines what is visible Submits geometry to the graphics processor Applies materials and lighting Composites the result Presents the frame
WHAT A DRAW CALL IS
An instruction to draw a set of geometry with a given state.
WHY THEIR COUNT MATTERS
Each carries overhead, and thousands per frame become the bottleneck.
WHAT REDUCES THEM
Combining objects sharing a material Drawing many copies in one call Merging static geometry
WHAT A MATERIAL IS
A shader plus its parameters, defining how a surface appears.
WHAT A SHADER IS
A program running on the graphics processor, computing vertex positions or pixel colours.
WHAT OVERDRAW IS
Drawing pixels that are later covered.
WHY IT COSTS
The work is done and discarded.
WHAT REDUCES IT
Drawing opaque objects front to back Limiting transparent surfaces
WHY TRANSPARENCY IS EXPENSIVE
It cannot be depth-sorted cheaply and must be drawn back to front.
WHAT CULLING DOES
Avoids submitting what cannot be seen.
WHAT TYPES EXIST
Outside the camera view Hidden behind other geometry Too small or distant to matter
WHAT TO MEASURE
Draw calls, triangles, and overdraw, per frame.
