Ipotrick

What is "Work Expansion"

In a GPU-driven renderer, "work expansion" is a commonly occurring problem. "Work Expansion" means that a single item of work spawns N following work items. Typically one work item will be executed by one shader thread/invocation.

An example for work expansion is gpu driven meshlet culling following mesh culling. In this example a "work item" is culling a mesh, where each mesh cull work item spawns N following meshlet cull work items.

There are many diverse cases of this problem and many solutions. Some are trivial to solve, for example, when N (how many work items are spawned) is fixed.

Ipotrick

import java.util.*;
import static java.lang.System.*;

public class IO {
  public static void print(Object object) {
    out.print(object);
  }

  public static void println(Object object) {
    out.println(object);