The process of CAD modelling starts with digitizing blueprints of the original rolling stock. The faded, degraded detail of many original documents can often be retrieved by using photographic processing techniques of the digital images.
One problem with using the blueprints is finding all the information for each specific model, sometimes this can only be found from different sources. Another problem is the variation in quality across a single blueprint, often the corner with the legend and reference measurements has been exposed to light and substantially faded. Ink can also be faded away on fold marks and critical measurements lost.
The blueprint we photographed showing the assembly of the GY wagon contained examples of several problems in the retrieval of information, however, because it was so common it is worth modelling for a train simulation. It also makes a good trial model as it is not as complex as a locomotive.
This is the unprocessed RAW photo of part of the blueprint.
This is the same photo after post processing.
The detail can now be seen clearly and is usable for creating new drawings and models. This is one of the most degraded blueprints we have photographed to date.
The Victorian Railways GY wagon was one of the most common examples of rolling stock on the tracks. This wagon was primarily used to haul grain after the wheat harvest but also variations were used for other purposes. When carrying wheat a tarpaulin was erected over the top.
This GY wagon was the first attempt our project manager, David, made at modelling in 2009, without using modern CAD software. The only information he had was a basic drawing.
We are re-creating the GY wagon using our new production pipeline.
The railway track is an essential part of any train layout. The shape and dimensions dictate what can run on it, the route defines where it will run.
To make a track for real rolling stock to run on, the material used is critical. The supporting media for the track are also important to provide the necessary rigidity so that the train will not derail. For a virtual railway the appearance of the track is the critical factor.
Railway tracks in Victoria, including the Maldon to Castlemaine route, were laid down in the Broad Gauge of 5 ft. 3 in. (1600 mm). They were supported by wooden red gum sleepers laid on compressed earth, leveled rock or over wooden trestle bridges. This was to keep the gradient at no greater than 1 meter rise in 40 meters traveled, allowing the locomotive to haul a load uphill and brake safely going downhill.
The tracks and sleepers are modeled in a CAD package to real specifications, then exported into Modo to generate normal, displacement and specular maps to apply to an optimized model for the game engine. Textures are created from our huge collection of photographic references, these go through significant processing before being applied to our 3D models.
Once this is done we can generate ray trace renders in Modo and show our final models to our followers. At this stage we also export them to the game for our world builders to use to create the route.
A picture of the high resolution CAD model, untextured, rendered in Modo. This is a work in progress, the plates and pins are still to be modeled.
The same model fully textured for visualization purposes, these are not the final textures.
This high resolution model will be used to generate the normal maps for an optimized low polygon version.