Tuesday, 22 July 2014

The Building of Belah Viaduct - Part 3

By Phil Baines

  In the final photo of my previous blog you can see the bottom of the columns rested on concrete bases.
  So my next task was to model these, which was quite simple as they were tapered cylinders. As they were painted black, similar to the bottom of the steel columns, I saw no point in creating shadow baking for them, so having produced one, it was a simple copy and paste operation to put in the other 95.
With the supports and decking complete that left the abutments at each end. The East abutment was a fairly simple structure set into the hillside

  The West abutment was virtually identical, but with wings added.

  Fortunately, Peter Walton's book provided a side elevation of the East abutment and I was able to model the East abutment from that. Next I cloned the abutment, added wings and I had the West version as well.

  Two more jobs to do and the finished article could be assembled.
Firstly, the abutments were textured with a tiling material which is a quick way of texturing large objects, but the results look too even and un-lifelike. The addition of the shadow map gives some depth to the model, but on large items like this I like to add a bit more. So, I open the shadow map in photoshop and using greyscale colours with a selection of "grunge" brushes, I add random splashes of weathering to the shadow map. Nothing too complex, at 30mph the driver won't notice too much! Grunge brushes are readily available as free downloads on the net and well worth getting.
Finally, I look at all the objects I have created to assemble the bridge and, where suitable, I select and clone any upwards facing polys. These are then combined into a single object called snow. I raise this object by a couple of mm to stop its polys z-fighting with the polys they were cloned from, then apply my snow material. This is composed of two textures, a default season texture and, using the _wi suffix, a winter texture. The winter texture is, obviously, white snow, but, for the default season texture, I use an invisible texture (just a copy of the invisible texture I use in Viaduct building lofts), so nothing shows except in winter.

  The Belah viaduct was now ready for inclusion in the game and I hope you have enjoyed my description of how it was achieved.

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