This week in class we created a realistic representation of rain using particle effects and real world scale. For homework, we had to recreate this effect but in one-tenth the scale we were using. Once I finished recreating this rain effect, I noticed several pros and cons with working on a smaller scale.
With rendering there is a necessity to work at real world scale as it is important for light to be represented in a realistic manner. However, with dynamics and particles this is different. Particles can be created at a smaller scale as this can sometimes be quicker and cheaper.
However, I noticed when scaling everything down that certain values such as the magnitude of the gravity and turbulence field didn’t need to be brought down. This confused me slightly as I had assumed that everything would need to be scaled down to recreate the same effect as the real life scale. This made it confusing to understand what needed to be scaled down and what needed to remain the same. I made the tail size of the rain drops considerably smaller as the scale of the scene is considerably smaller.
When I was creating the colliding particles emit more particles when the rain hit the ground, I had trouble forcing the particles collide with the ground plane. They instead passed through whilst emitting more particles. Once this problem was resolved, I noticed that the particles continued emitting forever even though all the particles were set to constant for 0.5 seconds. I could never resolve this problems.
Despite all these problems, working at a smaller size scale still has its benefits as it creates a quicker, cheaper result. However, when working at a real life scale, I found that I ran into less technical problems. Working at real life scale also gives a more realistic representation as it is at life scale. Therefore, I believe the real life scale is superior if you want a better result.