Since we don't have radar or distance sensors embedded in our brains yet, we need to rely on our eyes and ears for cues on where something is, and this is even more important on video games since unless you use a 3D monitor, the view you are seeing is 2D. (Yes, even with 3D games. The monitor is still a flat 2D plane where everything is squashed into a single,flat view, so there goes your stereo vision)
So what can be done visually wise? Shadows someone might say. Well yeah, that is number one in the list but it's not just that. There are a couple things more that can be done in the levels themselves to show the spatial relationship of things. (Spatial relationship, bet that made me look smarter than what i am). Take a look at the image below for an example.
The image shows a level from a game that you have to stop the blue balls from falling in the pit, a pretty basic premise with no story behind it. The top part has the shadows disabled. It looks as if the balls are just pasted on top with little to tell you the distance from the ground at a glance and you don't really have time to observe because that thing is coming at you and you need to throw it back. The bottom half has the shadows enabled and the player can see exactly where on the playing field the ball is and how high.
But that's not the only cue. The pit is textured in a checkerboard like pattern. That makes it even easier to tell where the ball is going to be the in the future (since the balls fall towards the centre, you can use the pattern as a guide) and give you time to turn the paddle at that angle to throw the ball back. There is also a trail effect. That not only shows the general direction of the ball but also if the ball is going up or falling down, its angle and its speed.
(The shadow may look as if it's a bit ahead of the ball but actually it's right under it. The camera used is wide so it makes it look like that, a tiny bit - sort of - fisheyed).
P.S. Since this is for a mobile game, the shadows are not real time.The shading on the level and glove/paddle are baked (drawn) into the texture and the blob under the balls is from a
script solution from Unity's Asset store.
Sad box is sad. And unshaved...
