This was a fun modern OpenGL demonstration showing the bountiful possibilities that could happen when you bring computer graphics and stressed undergraduate students together! Wait.. I think I said that wrong.. computer graphics and creativity!
Anywho... below is a short video of what we made! :)
Link: https://www.youtube.com/watch?v=LGYbFkSXVtw
Why particles? Because now the simulation looks way more festive than it should be! We have a particle engine that generates roughly 500 particles through instancing. Each particle moves/lives/dies independently of one another. A random number generator is used to determine the direction the particle is moving towards, as well as how long it'll keep that direction. The particle will also be assigned a random life span. When a particle is just created, it'll appear bigger and is less transparent. As the particle approaches the end of its life, the size of it decreases and begins to fade out. All in all, we can just accept it's a giant confetti party.
Next up, we added shadows and phong illumination to the simulation. This makes the graphic in the game even more realistic. So realistic you have to believe that a bumper car arena hoisted in the air by a giant blimp is possible! Because it is o_o. With regards to creating shadows, we needed to render the shadow in two pass. In the first pass, we created a depth map from the perspective of the light source (sun). In the second pass, we will render all our objects as usual. But the key here, is we would use the depth map created from the first pass to determine if a pixel is in the shadow or not. If it is in the shadow, we would apply the shadow (darken the area) using the Poisson sampling technique. This softens the edges of the shadow to make it look more realistic.
How could we make driving a bumper car around in the middle of the sky even more fun? Add fog. A lot of fog! It's almost like driving with your eyes closed! How fun is that? JK. Don't do that. In here, we basically have two planes; a near plane at the camera (0% fog) and a far plane away from the camera (100% fog). The idea here is we would determine how far the object is from the camera and calculate where it sits respectively within this near and far plane. We would then mix the color of gray with the object's color accordingly based on how far the object is from the camera. This in a sense gives the impression that the object is in a foggy environment.
Finally, we can't possibly have a bumper car simulation if we can't detect when two cars have collided. Therefore, we created tightly bounded boxes around each of the vehicle and checked when any portion of the box is intersecting the box of another vehicle. When two or more boxes overlap with each other, we know that the vehicles have collided. Once a collision is detected, we need to determine how the vehicles should respond. We do this by determining which vehicle is at fault. Which vehicle is the one hitting the other. This is done by looking at the vehicle's position and direction to determine where it's heading. Once this is determined, our simulation would change the direction of the vehicle who is at fault so that they're no longer on a collision course with one another.
This was done as part of our final project for UCSD CSE 167 and was posted with permission from Professor Ben Ochoa.