Back to Physics in Simulations
AdvancedAdults
Building a Simple Physics Engine
A physics engine is the part of a game or simulation that calculates how objects move and interact. Let's outline a very simple one for a 2D world.
Core components:
1. **Objects:** Each object needs properties like position (x, y), velocity (vx, vy), acceleration (ax, ay), and mass.
2. **The Game Loop:** This is a loop that runs continuously. In each 'tick' of the loop, you update the state of all objects.
3. **Update Logic (per tick):**
a. Apply forces: Start by applying constant forces like gravity. Gravity would increase the y-acceleration of all objects.
b. Update velocity:
c. Update position:
d. Reset acceleration:
This is the basic 'Euler integration' method. It's simple but can be inaccurate at high speeds. More advanced engines use methods like 'Verlet integration'.
Core components:
1. **Objects:** Each object needs properties like position (x, y), velocity (vx, vy), acceleration (ax, ay), and mass.
2. **The Game Loop:** This is a loop that runs continuously. In each 'tick' of the loop, you update the state of all objects.
3. **Update Logic (per tick):**
a. Apply forces: Start by applying constant forces like gravity. Gravity would increase the y-acceleration of all objects.
acceleration.y += gravity_force.b. Update velocity:
velocity += acceleration * time_delta. The time_delta is the time since the last tick.c. Update position:
position += velocity * time_delta.d. Reset acceleration:
acceleration = (0, 0) so forces don't accumulate incorrectly.This is the basic 'Euler integration' method. It's simple but can be inaccurate at high speeds. More advanced engines use methods like 'Verlet integration'.