Perception and its Importance to Modelers

This article is a condensed version of a clinic titled “Mind Games” which I presented at a National Narrow Gauge Convention in Durango, Colorado about fifteen years ago. In the original clinic, I went into into significantly more detail about sensory perception – particularly optical illusions, and how and why we see models the way we do. This condensed version concentrates more on the psychological and physiological aspects of perception. Although the clinic was intended for indoor modelers, many of the ideas are applicable to those of us with outdoor layouts.


Understanding Things That Affect Perception

There are many factors, both internal and external, which affect a viewer’s perception of an item or event. Some of these are of special interest to modelers because we can control them to our advantage. Others are beyond our control, but knowing what they are gives us insight into how our models are perceived.

Internal Influences

Perception is influenced significantly by internal physical and psychological factors within the viewer. These include not only the obvious factors like health and awareness; but also the less obvious ones like mood and feelings. The range of factors involved includes:

  • Physical Health
  • Awareness
  • Attitude
  • Knowledge
  • Mood
  • Feelings
  • Understanding
  • Workload
  • Interests
  • Conditioning
  • Needs
  • Desires
  • Expectations
  • Threats
  • Rewards
  • Intuition

External Influences

External influences which affect perception can be roughly divided into two separate categories. First, there are environmental factors which act upon both the viewer and the item or event being perceived. These external influences include:

  • Lighting Conditions
  • Viewing distance
  • Temperature
  • Acoustics
  • Air Pressure
  • Atmosphere
  • Time of Day

Secondly, there are characteristics which are unique to the item or event being perceived. These include:

  • Relative Position
  • Relative Motion
  • Quantity
  • Color
  • Texture
  • Frequency
  • Duration
  • Repetition Rate

Things We Can Do to Enhance Perception

There are several things that we can do beforehand with our models to enhance the perception of the viewer. The most critical is to select a model which will appear interesting, attractive, or otherwise have some relative significance to the viewer. It is also important to establish a frame of reference for the viewer; this insures that his knowledge and background of the subject will allow him to assess the model objectively. Another critical item is the issue of viewer expectations – just what does the viewer expect to see, and why.

The physical environment in which the model is viewed can be manipulated to accentuate the model’s positive aspects and to minimize the negatives. Affecting the viewer’s internal influences is a bit more difficult. Although we cannot totally change these, we can alter some of them slightly to our advantage.

Frame of Reference

Let’s do a mind experiment. In front of you I have placed three of my most prized models. The first one is a 1:64 scale K-37. It is a foreground model from P-B-L; #492, just as she looked in the late 30’s. Just look at the detail. See the cinders on the running boards; Jimmy Booth worked his magic here. Notice the subtle streaking effect in the weathering job. This is definitely one of the best models that Bill Peter ever produced.

The second model is a 1:220 scale model of the starship Enterprise. I bought it at a Star Trek convention several years ago. It is built from the actual blueprints used to make the movie replicas. If you look through the windows here in the front, you can see Captain Kirk and Mr. Spock standing on the bridge. Kirk is looking over at Sulu saying “Ahead, Mr. Sulu; warp factor one.”

The third model is a finescale 1:48 scale model of a Yahoo Widget. I spent almost three years making this model; it is my pride and joy. It represents the most critical inner components of a discombubulator. I machined it out of solid titanium and used a laser to etch the final details. The coating material is a bluish silicon dioxide wash, thinned and layered to represent the heating effects of the extreme temperatures encountered within the discombubulator.

Okay…end of experiment. What’s going on here? First of all, there are not really any actual models to look at. All three only exist in your imagination. The first one seems real enough. After all, you are all model railroaders – narrow gaugers at that – so everyone knows what a K-37 is. You’re probable familiar with the term “foreground model”; if you have ever read the >Gazette, you have seen P-B-L’s advertisements on the back cover. You may even own a foreground model. If you’re into S scale, you probably know who Jimmy Booth and Bill Peter are. You understand cinders, running boards and weathering. Even though this is an imaginary model and you can’t see it, you can definitely perceive it.

The second model is familiar to most of you. Chances are that you – or someone in your family – have seen images of the starship Enterprise. Perhaps you watched the old Star Trek television series or saw the movies. You probably know who the characters Captain Kirk, Mr. Spock and Sulu are. You remember what the bridge looked like. I bet you even know what “warp factor one” means. You can also perceive this imaginary model – maybe not quite as vividly as the K-37 over there – but still, well enough to form an image of it in your mind.

The final model, my Yahoo Widget, is a mystery to you. You’re not quite sure just what it looks like. You know its a pretty good model, based on my description; but all you can really perceive is something made out of titanium with a blue coating. You’re not even sure what a discombubulator is or what it does. And since there is nothing to compare it with in your mind, you have trouble perceiving it as a real image.

This mind experiment demonstrates what the term “frame of reference” implies. Simply stated, in order to perceive an object, you must correlate it with some common reference point. The reference may be a real object, such as a K-37; or it may be a conceptual object, such as the starship Enterprise. In the case of the Yahoo Widget, you have no common reference to correlate it with; therefore you are unable to perceive it as a modeled object.


Always try to use the “Rule of 3’s” in object placement at points of interest within your modeled scene. This means that a particular item – whether it be a color, a texture, or some other stimuli – is used exactly three times and at various locations within the scene. The viewer’s eye will automatically connect the three items and will form a pattern. The viewer’s attention will jump from item to item in succession, creating visual interest.

Remember to vary textures and colors randomly throughout the scene. This avoids creating unintentional patterns. The natural world is not uniform in color and texture; real vegetation is not limited to three shades of green in fine, medium, and coarse. It is critical to decrease the intensity, size and spacing of objects with distance. Avoid using similar colors, textures and objects at both the front and rear of a modeled scene. When placing multiple objects in a scene, avoid even quantities. Always use odd numbers – 1, 3, 5, 7, etc. This applies to man-made as well as natural items. Use random spacing and irregular intervals; again to avoid the creation of unintentional patterns. The only patterns perceived in your modeled scene should be the ones that you purposely create.

Motion and Live Action

Perceived motion enhances perception. The perceived motion does not necessarily mean real live action. Anything that causes a perception of motion will enhance the believability of a model. For example, very few natural objects are perfectly still, although the rates of movement vary tremendously. The slightest breeze will cause leaves to move. Water is almost always in motion. Even the largest mountains gradually tumble into the valleys below. We expect motion in the real world, and its absence in modeled scenes causes us to sense that something is missing. Real live action is usually limited to the moving trains on a layout. Other live action can actually detract from a scene, and even cause it to appear toy-like and unrealistic. The illusion of motion is much more effective in creating perceptions for the viewer.

Try keeping the air in motion over your models to create an illusion of a slight breeze. I use small 12 volt DC cooling fans from personal computers set to run at about four to six volts. They are quite small and can be hidden out of site at various places in a scene. They cost about five dollars new, but can usually be scrounged for free anywhere computers are repaired or scrapped. They draw about 100 milliamps of current each. Ten to twenty can be run from an inexpensive power pack from a toy train set.

I try to add mechanical sounds inside of modeled buildings, particularly industrial sites. When the sound stimulus is received by the viewer, he automatically associates it with the machines that caused it. Even though the machinery itself is not visible, the viewer imagines it in operation and thus perceives the motion.

Ripples in a modeled stream, together with the sound of moving water, are enough to create the illusion of motion. Fallen debris in the modeled scene is also very effective in extending the illusion. Scattered leaves around a tree indicate that they moved. Maybe the viewer didn’t see them actually drop from the branches above; but his correlation with the real-world tells him that they did. Similarly, fallen trees and talus slopes are strong perceptual clues that motion is taking place within your scene.

Putting It All Together

Assuming that we now know enough about perception to have created the ideal model, it is time to show it to our prospective viewer. There are other “tricks-of-the-trade” that we can draw upon to further enhance the viewer’s perception.

Setting the Stage

The most important thing we can do is to eliminate visual competition. We accomplish this by controlling the perspective – even altering it if it is to our advantage. We need to carefully set the field of view, eliminating both foreground and background distractions, and forcing the viewer’s eye toward the intended focal points. Finally, we need to carefully plan the viewing angles since we have used different colors, textures, and intensities in different areas of our modeled scene.

We must also optimize the viewing environment. We do this by carefully selecting the lighting color, temperature, intensity and direction. In addition to lighting, we should optimize other ambient room conditions such as temperature, relative humidity, odors, and acoustics.

Finally, if at all possible, we should synchronize the modeled time of day as close as possible to the actual time of day when the model is most often viewed. This single factor helps to eliminate the confusion which occurs if the viewer’s internal body clock is out of sync with the visual stimuli presented to him by the model.


Add plenty of supporting actors to the scene. These are the sensory stimuli that compliment and reinforce the primary modeled object. They may include sights, sounds or smells. The supporting sight stimuli – such as additional colors, patterns and textures – should be similar to those used in the primary modeled object, but less intense. Remember not to let the supporting visual stimuli detract from the thing you want the viewer to see. Sound stimuli are great supporting actors because they do not compete directly for the viewer’s attention. They may include animal sounds, equipment noise, or natural environmental sounds. Smell stimuli also do not compete directly for the viewer’s attention. They can include natural environment smells, man-made smells, or industrial smells. In order to be effective, smells should be used sparingly and with as much distance as possible between them.

Hide surprises within the modeled scene for you viewer to discover. Don’t give everything away too easily. The object is to make the viewer think about the scene; to examine it more fully; to ponder its meaning. Be careful not to make the comprehension of the scene too difficult, or the viewer will lose interest. Try to use surprises that invite the viewer into the scene; things that make him feel good, or bad, or anything at all. If you can arouse any type of emotional response, then your modeled scene is working.

Present Living Stories

Create a purpose for the scene. Have a real or fictitious history available and, if at all possible, share it with the viewer before he even sees the modeled scene. Make sure that you know what message your scene is trying to convey to the viewer so you can answer any questions he might have. Don’t try to explain the scene to the viewer while he is looking at it. If it takes a verbal explanation, then it’s not a very good model. Your philosophy should be “Explain the past, show the present, and let your viewer imagine the future.”


Perception is a straight-line process, with input stimuli being constantly funneled to the brain for comprehension. The process consists of stimulation, filtering, processing, and response. As modelers, our goals are to keep the pipeline open; to keep data flowing through it; and to include meaningful information within the data stream. We must remember to control the characteristics of the modeled item closely, and to select complementary stimuli for our viewer. It is critical that we regulate the external environmental factors so that we maximize the positive influences and eliminate or minimize the negative ones. We need to always be aware of the internal influences within the viewer that affect perception and to provide him with a suitable frame of reference in which to view our creations. By doing these things, we not only create more meaningful models; we are better able to share the enjoyment that we receive with those around us.

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