Brainwave

[planetmaker]

Boo.

Two sets of sprites(...)

beautiful - as always

[Bob_Mackenzie]

I agree

[PikkaBird]

As a hot air balloon has rotational symmetry about its vertical axis you could do it with two sprites (if using a square basket) or one if the basket was round

As a hot air balloon has no "front", you could do it with one sprite regardless.

[Leanden]

True, why would the hot air balloon have to turn to change direction?

[wallyweb]

True, why would the hot air balloon have to turn to change direction?

Don't hot air balloons tend to tilt slightly in the direction of travel?

[Zephyris]

True, why would the hot air balloon have to turn to change direction?

Don't hot air balloons tend to tilt slightly in the direction of travel?

Not particularly, remember they are completely stationary relative to the surrounding air, so why would they tilt?

[planetmaker]

True, why would the hot air balloon have to turn to change direction?

Don't hot air balloons tend to tilt slightly in the direction of travel?

Not particularly, remember they are completely stationary relative to the surrounding air, so why would they tilt?

Due to the gondala having both drag and weight.

[PikkaBird]

Due to the gondala having both drag and weight.

What's it dragging against if the balloon has 0 horizontal airspeed (which it does, since it has no propulsion)?

[Leanden]

[Supercheese]

Well, I've drawn some sprites for a police car -- well, more like resized and heavily modified some excellent freely available graphics for a police car. Anyhow, I'm ok with the results, but I wonder if anyone has any suggestions for improvement; this is after all my first attempt at spriting for a newgrf.

I used the red flash- and water-cycle pixels for the flashing lights, but as was mentioned in either this thread or the other one on emergency vehicles, the water cycle is out of synch with the red flash, and since it doesn't fade to black, but rather to blue, it isn't as easily distinguishable. Still, it looks better than red-only to me. Oh, also there is no company color at the moment, just a somewhat drab grey and blue paint job.

Anyway, attached are the sprites and a test-grf I made in NML. Parameters such as vehicle speed, cost, power, and other such are, of course, for testing purposes only and aren't at all balanced or realistic. The sound effect is also just something I quickly edited in -- I'll likely edit a better siren later.

Unfortunately, I cannot seem to figure out this darned "offset" concept properly, so the car sort of jerks around in some views. The NML documentation didn't seem to have any rules for offsets for the different compass views, so I'm at a loss...

EDIT: New thread for GRFs: http://www.tt-forums.net/viewtopic.php?f=26&t=56780

[planetmaker]

You may want to look for the TownCar NewGRF (or similarily named) which is thought to be used in conjunction with the similarily named AI which only has the purpose to build cars and send them on the road. It might be an idea to add additional cars to that NewGRF instead of yet another one

[kamnet]

Boo. Two sets of sprites, one with the burner on, one off. The graphics are all rendered so can be scaled easily, and 32bpp versions are easy to make too.

*droools* I can't wait to see these in action!!

Well, I've drawn some sprites for a police car -- well, more like resized and heavily modified some excellent freely available graphics for a police car. Anyhow, I'm ok with the results, but I wonder if anyone has any suggestions for improvement; this is after all my first attempt at spriting for a newgrf.

I used the red flash- and water-cycle pixels for the flashing lights, but as was mentioned in either this thread or the other one on emergency vehicles, the water cycle is out of synch with the red flash, and since it doesn't fade to black, but rather to blue, it isn't as easily distinguishable. Still, it looks better than red-only to me. Oh, also there is no company color at the moment, just a somewhat drab grey and blue paint job.

Anyway, attached are the sprites and a test-grf I made in NML. Parameters such as vehicle speed, cost, power, and other such are, of course, for testing purposes only and aren't at all balanced or realistic. The sound effect is also just something I quickly edited in -- I'll likely edit a better siren later.

Unfortunately, I cannot seem to figure out this darned "offset" concept properly, so the car sort of jerks around in some views. The NML documentation didn't seem to have any rules for offsets for the different compass views, so I'm at a loss...

I think this is a fantastic start! I honestly have no quibbles with any of it, even the glitches you mentioned. I would love to see the paint scheme also in white, and in brown. I played with having 1-2 cars patrol in a town without any orders, looked just fine. Especially worked well if you're using the traffic lights newgrf.

[SwissFan91]

Great work everyone.

You may want to look for the TownCar NewGRF (or similarily named) which is thought to be used in conjunction with the similarily named AI which only has the purpose to build cars and send them on the road. It might be an idea to add additional cars to that NewGRF instead of yet another one

Definitely this.

[andythenorth]

What's it dragging against if the balloon has 0 horizontal airspeed (which it does, since it has no propulsion)?

Is the force applied by air current against canopy and basket same? Probably when considered per-unit-area.

But won't there be a higher intertia to overcome for the basket (cross sectional area versus mass), which would lead to a small moment between basket and canopy? (The canopy will initally accelerate slightly faster than basket).

My physics ain't great

[Zephyris]

What's it dragging against if the balloon has 0 horizontal airspeed (which it does, since it has no propulsion)?

On a sudden change in movement of the surrounding air (and only then) the balloon will, for a short time, have non-zero horizontal airspeed.

Is the force applied by air current against canopy and basket same? Probably when considered per-unit-area.

Yes, per unit crossectional area, no, per unit mass.

But won't there be a higher intertia to overcome for the basket (cross sectional area versus mass), which would lead to a small moment between basket and canopy? (The canopy will initally accelerate slightly faster than basket).

Yup, exactly, but only when the surrounding air has changed suddenly.

In short if a balloon gets hit by a gust of wind the top will tilt away from the direction of air movement. But most of the time it will be perfectly upright.

[FooBar]

Unfortunately, I cannot seem to figure out this darned "offset" concept properly, so the car sort of jerks around in some views. The NML documentation didn't seem to have any rules for offsets for the different compass views, so I'm at a loss...

General rule for vehicles is to take the negative of half the height (or width respectively) of the sprite for the offset. This usually gives acceptable results which only require minor tweaking. When it comes to tweaking, hit ctrl+B ingame to show the bounding boxes (you may need to enable newgrf_developer_tools for that though). The key to success is to align each view in the middle of it's bounding box.

If you want you can check the Dutch Tram Set source. It has templates for trams of each length; these should be equally usable for road vehicles. As long as you put each sprite in the correct position in the template, the alignment should be good automagically.

[Supercheese]

Well, after much toil and awkwardness, I've finally managed to code up the hot air balloon using the splendid sprites Zephyris posted earlier!

Being eyecandy, it has 0 purchase and running cost. It took quite a bit of doing, but the burner turns on during ascent, and during normal flight the burner is activated for a short burst every so often to provide more lift.

The purchase sprite was shrunk to fit within the row, and the sprite in the details window tends to cover up a bit of text, but I'm not sure how to fix that...

Also, there is a parameter to disable the burner sound effect while the balloon is in normal flight, in case you don't like that sort of thing.

Anyhow, if you find any bugs, let me know.

[Leanden]

That is awesome

If only some other light aircraft had the same no running costs and purchase cost but were stripped of their cargo capacity. Would make for a nice Aircraft Eyecandy GRF. Fill the skies a bit

[ISA]

If only some other light aircraft had the same no running costs and purchase cost but were stripped of their cargo capacity. Would make for a nice Aircraft Eyecandy GRF. Fill the skies a bit

I have thinking to make something like military stuff... fighter, old fighter (spitfire and other WWII stuff), hangars and little runway tiles to connect things up... bit like little air show! The main thing is to not go big, because I don't find a lot time to draw things... So I should try to go tile be tile. Anyways if anyone have interest poke me and I maybe get a little motivation

[Leanden]

/poke!!