johnwhelan
Well-known member
Yes John you have been a great help not only to me but I'm sure others who have been reading this thread, I don't have any history with computers which is why I find it all so confusing, for example when I go to one of my station areas that has many many items making it up it takes quite a while for all the bits to pop into place, so is this the graphics card which causes this delay or another part of the computer ? and is it possible to get it to almost instantly be there ?
PJ
If its your own route then the answer is yes there are things you can do to improve matters, if its some one elses you can change a few things but the low hanging fruit has probably already been picked.
When you use an item for the first time Trainz has to pull it in from the hard drive, hard drive access time is measured in milliseconds, it gets stored in memory, access time nano seconds. 10,000 nano seconds equals one millisecond so by having 2+ gigs of memory you save a lot of hard drive accesses.
Second the work required by the game is split between the cpu and the graphics card. The driver on the graphics card tells the operating system the capabilities of the card. Trainz is written to only use one cpu even if two are present. Windows however understands how to use multiple cpus on the graphics card, except they are called stream processors or something similar on the graphics cards. Low end graphics cards do not know about 3d shapes such a cube so the cpu has to do the work, high end graphic cards understand what a cubes and cylinders so off load the cpu.
The textures have to be applied by the graphics card so you need to read them in from disk into pc memory then transfer them into the memory on the graphics card. More memory on the graphics card means it only has to be transferred across once. Less work more speed.
When you arrive at a station often you are seeing items for the first time and there is a lot of new items. Also many items have more polys for more detail. The size of the object doesn't matter, but texture does since that is what you see. Take a look at church lane, one of mine, it looks very realistic since it is basically a series of photographs pasted on a box. Poly count is 12, extremely low for a building yet it is 128 feet long and 24 feet deep so quite large. It needs a separate roof by the way.
So select items that are low in polys where possible. The other thing to do is reduce variety, Trainz is good at remembering something is a copy of what is has just worked out. So 12 different trees repeated 12 times has a much lower impact than 144 different trees and most people won't notice the difference, especially if you rotate them. Also beware of smoking chimneys the smoke takes cpu processing power so you get a frame rate hit, that varies according to how much smoke is being emitted. Note the locos and rolling stock in the shot all have the be calculated as well so heavily detailed items that don't use lod will slow the station shots down more than lighter items. Also six carriages the same is a lighter load than six different carriages. Ones with interiors and people you can see sitting inside all need to be calculated as well so are more demanding than simple blocks with textures applied.
The next thing is to try to get things into memory before the station shot. Odd items used in the station shot such as a cottage can be added to the line side before the station so they are already in memory, and their tetxures already in the graphics card memory.
There are a number of other techniques such as using lod (level of detail), this is using lower poly meshes which are faster to load and process when you are further away.
Have a look at how the sucessful layouts work and you may be able to pick up the techniques. Talking to people who have done this sort of thing helps as well.
The other technique is just to throw raw horse power at the problem, ie fast cpus and heavy graphics cards even then it helps to understand Trainzoptions.txt and so forth. There is a beginners thread somewhere that contains a lot of this infromation and its well worth a read. If you are into creating layouts look through the TRS206 content creation guide and other documentation that is lying around.
Cheerio John