You should be looking for different studies on the main aspects of the visual image. The biggest problem i see with your examples is they are not even close to full scenes.
They have good lighting quality and good spatial quality, but they lack texture and color quality, and that takes away a lot.

Look to reality, and pick a pallet for the area to match a real location people know the feeling of.
Pick a pallet to match known standard colors of the elements you want:
Red bricks, brown woods, green/amber/yellow leaves, silver metals, redyellow fires, blue waters, bluewhite ices.

Pick lighting to give both a direct feel for the player, but also note that viewers tend to see lit objects are more important. You can draw a player's eye to what you want them to focus on just with the lighting. But the ambient levels and colors tend to set the mood.

Pick an edge style: Smooth futuristic safe, square modern, worn edges of decay, rough edges of rocks/nature, sharp edges of rocks/knives for scary/unsafe, pulsating biology, square/sharp edges enclosing sharp patterns of industrial scenes.

Finally pick an area. Back to how i said your images were lacking too much.
Image 1 could be:
Industrial plant with towering machines.
Great hall of giant mosters.
Great speaking hall before a king.
Depending on the coloring, the lighting you have could be very safe, very omnious, or very scary.

Image 2 could be:
An office complex with lots of windows/skylights.
A parking structure.
A tunnel with overhead lighting.
A lava cave (large opening with lots of collapsed sections)
Depending on colors, again you could make this feel as safe or scary as you wanted. As natural or unnatural as you wanted.

Image 3 at first glance feels unnatural, very sharp, and somewhat omnious.
It isn't a set of shapes people naturally see. Now, had you followed the
edges of image 4 more closely, the edge type would have given a lot more reasonable feel to the image.
The only reason images 1 and 2 don't feel immediately "wrong" is most people are used to those types of edges in their modern life. But I doubt many people see edges anything like image 3 anywhere.

But the area you pick will determine direction to the scene but has to be chosen based on what options it gives and takes from the player. You have to be careful about the area depending on your gameplay. Does it feel wide open? just open enough? Cramped? Claustrophobic? Does it feel safe? Open enough to explore? Open enough for a sniper? Cramped enough for creatures to be lurking behind stuff? Cramped enough to feel limiting? is that limiting a good thing or bad?

When I read the original post, I understood that some part of the subject has nothing to do with texture or coloring, in the sense that a series of vertical lines are perceived differently than a series of horizontal lines.





The two pictures above do have differences in coloring and texture. But when I drew it, I especially use horizontal highlight versus vertical highlights. I tried to use horizontal highlight for the Night castle, but the result was weaker. For this particular comparison, I believe that the reason is that the viewer associates the verticale highlights with blood. The visual image was emulating blood. And blood flows downward.

I think while some of these effects have an evolutionary root, perhaps most of it are culturally conditioned. There is no more common principles shared by viewers from different culture than the number of commonalities in their cultures.

I remember a study on motional images with shapes of walking human beings. The study finds that when the shape was of a man, more people would perceive the shape as walking towards the viewer; whereas if the shape was a woman, more people would perceive it as walking away. The explanation by the researchers was that human child evolved to follow their mother and run away from men.

I suppose the older examples were how the brain fill in the mission information for incomplete pictures, and how the brain is conditioned to perceive orientation using light sources. Moths fly into lights because they thought it was the water.

On the other hand, there is a style where paintings were intentionally drawn to play tricks on this common syntax of perception. There are many examples, but since I don't study art I don't know the names or titles.

In photography for beginners, there was the concept of balance, where the goal is to take pictures that look stable. For example, a beginner is advised to include both wheels of a cart in the picture so that the picture looks complete. In design, people would do the exact opposite in order to capture movement, so that still pictures convey a perception of motion.

In music, beginners learn a few chords to conclude the piece. Unlike visual art, I think it is much more uncommon where a composer intentionally compose the ending of a music such that it continues. So perhaps a fundamental question is "What is the difference between a spatial environment that appears complete and one that doesn't?"

Imagine a picture where on the left was a figure standing, while the right side is blank. The body of the figure is also facing left, but her head was turned to look behind itself. For a picture like this, the normal movement of attention of the viewer is as follows: First you saw the figure, then you notice its head is turned, then you look at the space that the figure is looking. Where the movement of attention ends, is the subject of the picture. This style of pictures are drawn so that the subject develops sequentially enought though the medium itself has no notion of sequential order.

In your first picture with vertical rectangular shapes, if the viewer (the player) is expecting obstacles coming from the sides, then to the player this spatial arrangement is "dangerous" because width is small so the available reaction time is small. However, if the viewer is conditioned to expect falling enemies, than this arrangement would be perceived as "forgiving" or "risk worthy", because the player feels that he is at least given a chance to react. In this particular way of analysing spatial arrangement, I need the assumption of not texture, not color, but perhap what you could call the direction of interactive force.

The level of oppression the player feels is inversely proportional to the dot product between the direction of interactive force and and the dimension of space.

For example, in your second picture with a flat walkway, an interactive obstacle that is an giant axe that pendulums from one side to the other would appear much more manageable than an obstacle that is a hammer that hits from above. Because the spatial environment gives the player more freedom to react to horizontal events.

The spatial depth in this case conveys the length of interaction (i.e. the number of times the player need to dodge the swinging axes.) I am only assuming one context of dodging obstacles. There are obviously other possible interactive contexts that would affect how the player perceive to environment. And I think that how the player perceives the environment depends on the player's knowledge of the modes of interaction. When the player sees the environment, the player is primarily interprenting it as an environment that defines the possible movements, (as oppose to an environment for one's viewing pleassure). I think this may be a main difference in analysis: In visual arts, the viewer views the picture as someone outside the environment. In this realm, the viewer projects itself inside the environment.

In your third picture, I didn't recognize it as a cave. I thought it was showing two spaceships away from a light source. So to me the picture was emulating a scene of "resupply"-- where a spaceship is docking to a station to load weapon or to evacuate while some explosion is happening from the right. I perceived that the explosion is sufficiently far such that I (the player) is not pressured to deal with that immediately, but to do something near the lower left quadrant first. If there is an entrance to the space station in that quadrant, I would assume that I was supposed to get inside the space station to do something important first although I know that the enemies are coming from the right. I saw that in the story, the spaceship on the lower right (which I can onl see a corner of it) would protect me and buy me some time, but it itself is in no condition to fight off the invasion (since it itself is a dark figure, so I perceive that it is an entity that would rather hide from the fight, as it is no match for the intense power of the enemy (light), but it would fight for my sake--or it would in fact ditch me when the enemy comes closer).

[Edited by - Wai on January 10, 2009 10:08:05 PM]

I made up the term.

I think the gaming environment is slightly different from real life environment.

In real life, a cave is where a person gets shelter from the sun, the rain, and the wind.

In a game, the sun the rain, and the wind are often times not a source of interactive stress. In fact, in the culture of games, caves are usually infested with monsters, so perhaps the directions are reversed (i.e. caves are not safe in general in the player's mind).

Suppose you have a 2D side-scroll game featuring acid rain that hurts the character. Suppose the player knows that roofs block acid rain. Then I think the locations under horizontal surface would appear "safe" to the player. If you let the player go inside a building where he could see the rain outside but not inside, then the interior would appear safe regardless of lighting condition. The catch is that the rain must be an actual interactive force (i.e. must inflict damage). I am thinking that, otherwise, the player would not perceive a difference between inside or outside a cave.

Another example: World War I trenches

Everywhere above the trenches is unsafe. Inside a trench is safe (relatively). The locations of safety depends on the perceived sources of relative danger.


I think that the common sense used by gamers are significantly different from those those gamers use in real life. The reason is that the sources of danger (or, equivalently, assistance) are often significantly different.


In a 3D game with cosmetic weather effect, I actually do feel more homely inside a cave, especially when I know that I am not deep enough for the monsters. It could be because if I were in the open, monsters could spawn anywhere and aggro me. In a cave, there are specific spawn spots. I definitely feel safer in an open city where there are no monsters, versus a cave, but on the other hand I have a stronger wish that a monsters in a cave don't aggro versus monsters in the open don't aggro. Is that because I prefer to think that caves should be safe, or that I subconsciously know that if I get aggroed in the open I had a better chance of escape? In a city space, where nothing could aggro, I do feel more comfortable indoor. Does this settle the question? Is it because less stuff is moving indoor, demanding less attention energy, so I associate it with a place to rest, giving me mental comfort? I could close my eyes for a few minutes and my brain don't need to notice any change when I look at the screen again.

In your cave photo (not the abstract one), I don't particular feel save inside the cave because the roof of the cave has a triangular shape, and the light could clearly get it. The wall was rough. There is no flat surface to sit, and the cave was flooded. I don't want to touch the water or to get into the water. To me, it felt more like a dead-end with nowhere to rest. It didn't feel safe to me. You could tell when you look at it closely that there are flat surfaces near the people, but that is not where my attention ended (my attention is drawn to the rough surface that got the light). So if the cave light was shining more downward instead of horizontal, and on the flat, homely surfaces it would feel more safe. I also think that if the opening is closer to the middle of the scene it would feel safer, because although it is still a dead-end, an exit in the middle feels more accessible. It would imply to me that the cave was not meant to trap the player. The player could exit the cave anytime. No matter where I explore in the cave, I would still be closer to the exit (I am still thinking in 2D sense).

[Edited by - Wai on January 11, 2009 12:34:16 AM]

There is an article one the effects of level shape somewhere on Gamasutra.com. I don't remember the title though.