TRAINZ CARRIAGE & WAGON WORKS UK
Component Housing by John Whelan
Often when you look at a UK layout one of the things that strikes you is the repetition of one or two terrace houses. From a performance point of view using one item repeatedly is good, from a visual point of view it gets a little uninteresting.
Placing eight houses in a line means six cubes for the house with six textured sides each plus six roofs with five textured sides and a minimum of 8 polys per house and six per roof. These can be combined but normally the roof has a slight overhang and the totals remain much the same for a minimum total of 112 polys. Add in a couple of architectural details such as chimneys and chimney pots and the poly count takes off.
Trainz gets impacted by two things, the first are the number of polys and the second the size of the texture files, so one design goal is to increase the variety whilst keeping the machine impact down.
Eight terrace houses in a row is one cube, the walls between houses don’t need polys or textures. If we stick to a standard size for the terraces we can reuse the roof which gives us the second and subsequent roofs for very little machine impact, same for the chimneys and chimney pots. We can also use lod to reduce the machine impact of large textures which give good levels of detail close up.
Another design goal is to give more flexibility to layout designers at a lower “cost” to vary items. Although there is a lot of free content on the DLS often a layout designer would like something a little different than what is available. Many people who create in GMAX have a back log of requests, are taking a break, or have got involved in something that is technically interesting and would rather not drop every thing and create to order and even if they do custom content can take time to create. The alternatives of learning GMAX and how to reskin can be frustrating as well as expensive in time.
It is interesting to note that although the original concept was eight terrace houses that would be much the same except for different coloured doors and curtains reskins with a different number of houses in the terrace have appeared and even different sized houses. With a conventional model the chimneys would be fixed so would look out of place using components chimneys can be added without touching the GMAX files.
Many UK terraces had extensions built on the back, by using components we can add these and if we repeat them we get low machine impact but combine them with different coloured back doors and windows on the terraces we still get some variation.
The long roofs use the same texture front and back plus tiling to reduce the size of the texture required but only four tiles so it reduces the texture size by a factor of four without being too obvious.
THE TO DO LIST
The intention at the moment is to create some bay windows for the front, garden walls, more chimney pots of different varieties, street signs, flagged pavements (raised sidewalks), gardens with Chameleon so they have a layer of snow when it snows, and roofs with Chameleon again to show snow covered roofs.
HOW TO USE THE COMPONENTS
First place the terrace, orientate it etc. Then add the roof. You may find that to do this easily look at it from immediately above to get them lined up and then go to a side view to tweak them slightly if they are slightly out of line. If you are using the 16 high basic terrace the roof is the correct height, if you are using the 24 or 32 foot version you will have to rise the roof. Note that the 32 foot high building has the same impact as the 24 foot high version and uses textures that are twice the size of the 16 foot high version. The poly count is exactly the same for all three. There are versions that tile the back, this lowers the machine impact but reduces the variety.
Next add in the chimneys, and chimney pots, the latter are normally 28 feet off the ground which should be correct for the 16 foot high terrace using a six foot high chimney. Then add in any rear or front extensions and roofs etc.
Note that the roofs in general use the same .tga file for the semi, back roof and terrace roof so if one model has a roof you like but is the wrong size try copying the texture file from that model into the folder of the correct sized roof. In TRS2006 I suggest you clone it first.
Also the gable ends on the roof with two different ends use the same size .tga file “terrace roof ends.tga” as the terrace ends “terrace sides med.tga” and the left side is on top on both. Often with a plain terrace end it is possible copy this file in from the terrace sides med.tga to match the brick work. Currently the roofs do not use lod.
LOWERING THE MACHINE IMPACT
For those with lower end machines the impact can be reduced further, although the first recommendation is to increase the memory to 2 or 2.5 gigs first. Replace smoking chimney pots with the none-smoking variety. Also replace differing chimney pots with the same style; square ones are lower polys than round ones. Reduce the variety of terraces by replacing them with the same terrace. Technically it is possible to use Chameleon to give snow on roofs if it is snowing etc. These items have a slightly greater impact than items that do not use Chameleon.
Within the item folder is a file body.lm.txt that has the lod information. The file is referenced in config.txt. It is possible to remove the largest .im file from this file which will prevent Trainz from using the largest meshes. Use notepad to edit this file and take a backup first.