How much is too much?

[hertsbob]

I would imagine one of the issues with using tons of wagons in a scene is that they're not LODded very well.

Hi

I think as much of the problem may be that the physics of all the wagons is being calculated? Or does the problem go away if you use real low-poly wagons as opposed to low (or high) poly scenery-item wagons?

Bob

[SMMDigital]

Draw calls will be the issue with my loco then. In the beginning, I tried fitting all of the non-see through alpha parts on one 1024x1024 texture (didnt know you could do 2048), and in the game the texture quality was horrid. So I went with two 1024 diffuse textures for all parts that would have a bump or environmental map, and one 1024 for all parts that have see-through alpha. Every square inch of those textures are filled with material, so not much space was wasted.

However, there was some overflow that I could not fit on those texture sheets. I kept the TrainGlass textures separate because I found that if you make them small and fit them on your main texture, when the game blows them up you get the polka-dot artifacting instead of clear transparent windows. Then you have to account for your Environmental texture, which is replaced in-game by reflection effects; normal maps; and a small dummy texture for your Emissive light effects.

I'll know better, if there is a next time.

[eyein12]

I have been using 2048X sheets on my building maps but the only issue really with this is the large file size you get. 10Mb per building adds up awefully quick. 1024X sheets use up roughly 2 mb so...as long as you have a big HD then your good.

answering a previous post about exterior model being 17K polys and interior being 20, well answer is yes your total is 37K...IF you chose to add in the cab to your external model. otherwise they are sperate.

[Kali]

Hi

I think as much of the problem may be that the physics of all the wagons is being calculated? Or does the problem go away if you use real low-poly wagons as opposed to low (or high) poly scenery-item wagons?

Bob

Maybe, need to try and drop brakeless vehicles off a train & see if they stop at some point. The sensible thing would be that they don't have any physics until you're about to interact with them, or unless the environment is interacting with them ( and then they only need basic physics ) - I was assuming that's what happens when you drop a bit of a train off and it stops dead.

Off you go, fill a yard with highpoly scenery ;)

[hertsbob]

If you drop off brakeless wagons on a hill they roll away.

The only way I managed to get any sort of hump shunting to work was by using wagons with no brakes whatsoever and increasing the friction values. This was OK but would result in a set of yard-specific wagons in order for it to be of use.

Should I try rows of 65xPaddington Station as a test?

This is obviously a related thread that I've only just noticed. http://railworksamerica.com/forum/viewtopic.php?f=6&t=6118

Cheers

Bob

[Kali]

Do they ever stop before they run out of momentum? I guess dropping braked cars off jamps the brakes on then, somewhat unnaturally quickly.

In which case, no that won't be helping fps at all... and an obvious area for optimisation.

[hertsbob]

Do they ever stop before they run out of momentum?

No idea. I did a scenario for Netherfield in which I dropped off a rake very early on which gently shuffled off until they hit the buffers and derailed about 10 minutes later.

I also ran a set of wagons with no brakes and no friction value (or very little) off the top of one of the Wath humps and they never showed any interest in slowing down at all.

All good fun.

Cheers

Bob

[BNSFdude]

The trick I learned from MSTS model making is the fewer textures the better. I use 2048s for the hood, trucks and rear section details of my GP30, and 1024 for the cab side and small details on and around the cab.

[Kali]

Bob, do you think you can try a scenario that you think is slowing down because of excess wagons, only substituting low-poly versions? not scenery objects, actual wagons. I don't actually have a scenario which I'm convinced is having problems from vehicle count rather than chuggy scenery.

Thing is, wagon physics ( especially when they're not attached to a driven vehicle ) should be pretty dern simple, if it's slowing down the game then we should probably bring it up.