Transport Tycoon Forums

Can road vehicles in OpenTTD make use of the realistic acceleration properties 13, 14 and 15 from the NewGRF specification?

http://wiki.ttdpatch.net/tiki-index.php ... _13_14_15_

I am developing a road vehicle NewGRF set which is principally intended for OpenTTD. It would be very useful for the gameplay balance of the set if vehicle horsepower made a difference to the hill-climbing and acceleration performance of the vehicle.

I have been unable to work out from the documentation whether these properties are supported in OpenTTD, or whether they are specific to New Mountain and Curve Handling in TTDPatch.

Apologies if you feel this should be in the OpenTTD Graphics forum - I felt it was more of a development question that needed knowledge of the codebase.

cheers,

Andy

http://wiki.openttd.org/wiki/index.php/ ... cle_speeds
Here you can see that RV acceleration is fixed at 37 km/h/day, i.e. not depending on any (NewGRF) property.

IIRC all NewGRF properties regarding (realistic) acceleration are ignored in OpenTTD, including RV property 13-15.

Of course you can write a patch that implements realistic acceleration for road vehicles. It is not trivial, but it can be done. You may use the search if you want to look for the patch I wrote quite a long time ago.

hertogjan wrote:Of course you can write a patch that implements realistic acceleration for road vehicles. It is not trivial, but it can be done. You may use the search if you want to look for the patch I wrote quite a long time ago.

You wrote a patch long time ago to implement realistic acceleration for road vehicles? What was the issue with it (in other words why was it discontinued?) Did you hit any road blocks?

hertogjan wrote:Of course you can write a patch that implements realistic acceleration for road vehicles. It is not trivial, but it can be done. You may use the search if you want to look for the patch I wrote quite a long time ago.

Is that this one? http://www.tt-forums.net/viewtopic.php?f=33&t=22995

If some intrepid person was to produce / update a patch, I believe I have
some interesting ways to use it

IMHO, a complete physics simulation isn't absolutely necessary - it would be sufficiently beneficial to gameplay if there was some simple connection between HP, weight, and speed/acceleration. That would offer players more interesting choices involving a balance of vehicle power, purchase cost, running cost, also building flat routes, bridges etc.

A solid physics engine might actually be the easiest way to do that. On the other hand sometimes in games a quirky but-well-implemented hack can work just as well

cheers,

Andy

I'd rather go for Newgrf / modifiable options from the .cfg for the default trainset. If the user doesn't like the actual model, he should be able to change it.

andythenorth wrote:Is that this one? http://www.tt-forums.net/viewtopic.php?f=33&t=22995

Yes it is. But it is outdated so getting it to work might cost quite some effort.

nicfer wrote:I'd rather go for Newgrf / modifiable options from the .cfg for the default trainset. If the user doesn't like the actual model, he should be able to change it.

I believe that we are talking about road vehicles, not trains.
But for your information, my patch is (was) highly configurable. You can switch between the simple acceleration model and realistic acceleration model just in the patches window. Moreover, all physical constants can be tweaked in the config file or the console, so that you can still enjoy the effects of realistic acceleration even if you dislike the default setting for (say) gravity, or the amount of air drag. You can just set them to a lower level if you like.

But I think that patch is history. Or if there are enough people requesting it, then I might put it back to life.

hertogjan wrote: But I think that patch is history. Or if there are enough people requesting it, then I might put it back to life.

Well, it would be useful to be able to code road vehicle newgrfs with some variation in vehicle acceleration, hill climbing ability etc.

It is also useful in order to allow maximum speeds above 127 km/h.