HOW TO PLAN & SET UP A MODEL SCENE

EXPERT MODELLERS SHOW YOU HOW

An effective backdrop can make or break a layout. As Paul Bambrick explains, it’s often best to plan this element at an early stage, as it may need to tally with scenic contours and may even dictate the size and shape of your baseboards.

These are a few of the basic steps that I take when starting out with a scenic layout or diorama. It’s just a sequence of safeguards that might help to keep a project out of trouble at a later stage, so if you are planning a scenic layout, I hope they come in handy.

To get the best from your scenic work, it’s going to help if we have a quick look at a few aspects of human perception, so we can understand best how it may benefit your project.

WHAT’S OUR PERCEPTION?

When it comes to the surroundings of a railway model, we’re really after a convincing illusion of the locality. Sometimes it will need to be an accurate and prototypical ‘window into the past’, (like this example), but it might also be a more generic depiction to suit an imaginary railway. In either case, there are number of methods that we can employ to persuade the viewer into perceiving a modelled landscape as a real place.

The ideal configuration for any diorama backscene is a semicircular arrangement, replicating our natural survey of the surroundings, but with the typical linear nature of railway models, it’s often the case that there’s insufficient room for this, and a linear panel is required instead, running parallel to the railway itself. This can lead to one of the first problems when doing a backscene, which is a vertical foreshortening of the image. The effect can be seen in the sketch, where the semi-circular diorama (upper) produces correct right angles, but the linear arrangement (lower) produces more acute viewing angles.

When we survey a real landscape, we see an entire panorama as we rotate through 360 degrees of vision. We can look up at the sky far above us, or down to the surface close by. With a linear subject such as a railway line, it’s normal to observe it from quite nearby because it’s the main focus of our interest. Only a directional left to right survey of the scene is required to see the trains in their habitat, so we can obscure anything we don’t need to see as unnecessary areas of the overall ‘picture’.

It’s the same process as composing a drawing, or cropping a photograph, but we are working in three dimensions, and so presentations like this are usually referred to as dioramas.

A layout or diorama is a partially contained panorama, therefore, and we’ll need to depict a false landscape within the available space for the railway to traverse, hopefully with a representation of distance included for realism.

In terms of human depth detection, our inability to triangulate at far distance means that we can only see a flattened image at the furthest reach, so a similar two-dimensional backscene is quite familiar.

HAVE A TRIAL RUN

A rough card mock-up like this can be arranged behind your baseboard, with a rear panel resting on card brackets, or horizontal wooden battens clamped in place. The rear panel can just be mounting card to start with, which is easy to fit in gentle curves. It can be joined up to make a full length panel by overlapping card joiners stuck on with Mitre Bond adhesive from the rear.

Before committing to anything, I find it’s best to create a mock-up, which can be made of foamboard or mounting board, curved to follow behind your model. Access points for scenic breaks can just be crudely cut out for the time being, and if necessary, it can simply be tack glued into place using extensions from the base boards.

The first practical step is to draw a pathway behind and around your layout, using the largest radii possible to try to get that ideal semi-circular rear panel shape. Use any means necessary to get the rear panel itself as far away from the rails as possible, by extending it well beyond any baseboard edges. Of course, there’s always a limit to the available depth that a backscene can occupy, but whether it’s a metre or a millimetre, that’s what you have to work with.

Obviously, the more allowance, the more realistic the end result can be, and I find the best method is to occupy the first half of the space with the first visual layer, then the next layer can occupy half of the remaining space, and so on, until you practically run out, by which time you have reached the rear panel. This effort will pay us back later by allowing the maximum amount of available depth.

The height of the rear panel can be decided by a number of factors, the first usually being a requirement to reach over to manage hand coupling for instance. If this turns out not to be the case, so much the better, as the higher you can get the sky panel to extend, the more it looks like the real thing. Sometimes you might just need to be able to see over the top of a panel, so this will dictate the ruling height, and in other cases, a physical limit may appear, such as a ceiling or possibly the roof beams of a loft area.

VIEW BLOCKERS AND LIGHTING

Backscenes often turn out to be long thin strips, due to the linear nature of railway models. This configuration can sometimes lead to problems with foreshortened images appearing in photographs or views of the railway from any angle not square to the layout itself.

Particularly with photographic or flat painted panels, this leaves the backscene exposed as a fraud, with an unrealistic foreshortening effect having to be dealt with as best as possible. The more 2D the backscene is, the more the problem is exaggerated.

So, what can be done to alleviate it? One answer is to include the use of view interrupting devices which are placed deliberately to obscure foreshortened areas of a backscene that are becoming unrealistic. These can really help with the land surface and sometimes even the lower sky.

Such devices are sometimes known as view blockers and they can be arranged to partition an awkward, linear backscene into several visually separated dioramas. These work surprisingly well, as the eye is persuaded into restricting its own view, largely remaining between a carefully arranged pair that have been cleverly placed to distract the eye away from a continuous flat strip.

Try any lighting out at the mock-up stage, as it might warn you of potential problems. A rear panel is a false distance and throwing unwanted shadows against the vertical surface is quite a common problem. Trees, spires, chimneys and other features standing above the skyline will do their best to throw directional shadows, so try a diffused light source and experiment to minimise problems.

VIEW HEIGHT AND HORIZON DATUM

This is a pretty typical viewing height for a scenic model, and it’s much higher than the scale figures. The people on the platform wouldn’t be able to see any distance at all with the train in the way, whereas we can see right over it. This makes all the difference when you are trying to come up with the best compromise for the horizon datum.

Now we have the best possible rear panel position, it’s time to deal with one of the most critical aspects of the landscape, the all-important ‘horizon line’. It’s where the land meets the sky at the furthest distance away from us, and so for now, it’s easiest to imagine your layout is situated on a flat plane, as far as the eye can see.

Now this datum is vital, but it’s still an artificial one in every case, as it’s unable to adjust itself up and down automatically to eye level like a real outdoor view. This is because it’s shown on a panel that’s too close by, and because of this limitation, we are forced to choose a compromise height for it. Our modelled horizon can be rightly criticised as being unrealistic, and it’s one of the most common problems with backscenes, but the negative effect of a horizon line that’s been set too low can be greatly reduced if the line is positioned at eye level to the average viewer.

This is also where the line, or rail height, comes into play. In practical terms, it’s the relationship of the trains, compared to your own viewing position. Most scenic models have a much higher viewpoint than a scale figure, and it’s why most reference photos can’t be used directly. It’s a personal choice of course, because the added elevation allows a good overview of the railway, but it’s also true that the further up you are, the further away you can see!

A 1.3m line height is quite a good starting point for a standing observer, so to get your flat horizon pencilled on, let’s see if your own typical viewing height is likely to be from a standing or sitting position? For instance, if you’re doing an exhibition layout, most of your visitors will be viewing the scene from a standing position, and that’s going to affect your choice of height compared to a sitting operator, who would typically be a foot and a half lower, relative to the railway.

It does make a huge difference; just measure a foot and a half in terms of your railway’s scale! It’s not a decision to be taken lightly, so take your time and maybe try a few printed out reference photographs of your intended backscene on the rear panel and judge for yourself what the optimum position would be.

Now we also need to remember that the skyline is different to the horizon line, and to explain this, just imagine for a moment that your scenic model is located in the middle of a completely flat plain without a single change of contour. That would give us a single horizon line and skyline combined, like being out at sea. If you are modelling an area of flat land, that’s absolutely fine, but most locations have land masses rising between the viewpoint and the far distance, and these naturally obscure any view beyond them.

The two lines now separate, with the skyline rising above the flat horizon datum. For now, just pencil in the flat horizon, and we’ll worry about the skyline later on. As long as we grasp the principle of an invisible horizon datum concealed behind obscuring land masses, we can continue on a safe foundation.

This backscene, featuring Kingswear and the River Dart, shows us that the skyline is different to the horizon line in nearly every case, unless you happen to be out at sea or in the middle of a vast desert plane (neither of which is a likely environment for a railway!). Land masses in between the viewpoint and the far distance can be superimposed onto your rear panel like these headlands, which rise up either side, to obscure the far distant sea level datum, which remains visible at centre.

PLOT THE SKYLINE

With the best horizon datum established, pencil the line level all the way around the backscene mock-up, as this will help you to apply the H skyline. The example here corresponds to the 3D backscene of Kingswear and Dartmouth (below), with the above graphic obtained via free online ‘Generate a Panorama’ software (https://www.udeuschle.de/panoramas/makepanoramas_en.htm).

It provides minimal information on local landmarks, but it’s just the thing for helping you to judge the lie of the land and for plotting the skyline. Combine the outlines of the land masses with maps and prototype references in order to get the basic contours.

MAPS AND CONTOURS

Lineside contouring from map reference can be combined to discern the lie of the land relative to the railway. You can see the line height above nominal sea level crossing at 185ft in this sketch, for instance, and of course, part of a mock-up job will have to include lineside contouring as well as distance.

SCENIC BREAKS

Scenic breaks allow trains to enter and depart the scene through a convincing, disguised aperture. It does have to be created in a consistent scale in relation to the trains, due to the aperture’s proximity to the rails, but the scale reductions that are apparent at near and far distances can be included gradually as you progress away from the scenic break itself.

Any contouring of the surroundings needs to correspond to the scenic break, so there’s a believable reason for an engineered bridge or tunnel. This example shows the railway in a deep cutting, eventually requiring a tunnelled trackbed beneath higher ground. Natural tree growth is a very forgiving element for producing scenic blinds and view blockers, particularly when modelling imaginary locations.

SCALE REDUCTION TO DISTANCE

We never ‘see’ anything in scale, even though we can measure something to prove its dimensions. The exercise of making a convincing landscape relies on following the natural way we see, which is known as perception, not the adherence to any kind of constant scale ratio. The lens of the eye generates a world where objects appear to diminish in size, relative to distance, and this familiar visual trigger is what we need to reproduce artificially.

In the world of scenic modelling, it’s often referred to as forced perspective, so unlike a traditional landscape painting or photograph, our efforts can graduate gently away from the two-dimensional rear panel into the three-dimensional scale of the railway.

To study the relationships of size reductions for reduced scale elements, have a look at the backgrounds of your layout reference images.