Cloudy Looking Shadows in games.

[Calyx]

Hi, every game I play that has shadows always has blury or cloudy looking shadows. Here is an example from "Only if" a free steam game.



If you look at the shadow on the wall that the chair is making, the shadow is cloudy looking, also on the skirting boards and roof corners.

Anyone know what is causing this?

[Agent]

Simple answer: It's the lighting solution the game is using.

Slightly more complex answer: Whenever you have lighting in a 3D world, you're normally trying to simulate photons bouncing around the scene. Every bounce takes processing time (either in real time, or pre-calculated before hand). In general, the more bounces, the more accurate the scene looks (this is somewhat a simplification). The 'cloud' effect you're seeing is a mixture of two things:
1) The 'photons' that are hitting in that area all bouncing a slightly different number of times before hitting, which means that different levels of 'shadow' are present.
2) The area is 'smoothed' with surrounding colours. This reason for this is mostly to stop pixelated dots appearing, which would look horrible.

Then you also have the lightmap resolution to contend with. You simply can't have a wall that has pixel perfect mapping of a large texture / material in most circumstances. They need to be downsampled, or you'd end up with a handful of assets taking up all of your GPU RAM

Again, this is a simplification of what's happening. A lot of the effect depends on the material (which is usually made up of multiple textures and math operations) these days, and not just the lighting solution. It's a complex area, and an area that can earn you a lot of money of you're good at it