I''m working on a racing game which will have deformable terrain. It uses a height-map, which can be changed mid-race to create depressions, hills, etc.. From the beginning I''ve wanted this so that weapons like land mines and missiles would leave craters. The racers are hovercrafts (think Star Wars speeders or pod-racers), btw, and can maneuver over just about anything but vertical walls. So I''ve got two questions for anyone bored enough out there: 1) Given enough weapons and time, a racer will be able to deform a section of track enough to make it impassable. The main example would be an over-pass/long-jump situation in which the racer screws up the bridge/ramp (such structures are separate from the height-map, but will ''fall'' if necessary to adapt to it). Yes, I actually want this. But how do I keep this wanton destruction from getting out of hand? The obvious solution is to have a "back-up" route, but that requires a lot of foresight. Note that I do not want to ever actually undo any deformations. 2) Terrain deformation could cut off or open up sections of the track, and this doesn''t necessarily have to be initiated by the racers. Remember in Wave Race 64 when that flood-gate thingy opens up after the first lap, creating a shortcut? I was wondering if you guys had any suggestions for this type of thing. I''ve only got time to complete 1 track for IGF in September, and I''m thinking its going to have a Aztec/Amazon/jungle theme (how ''bout a volcanic eruption on the last lap?).

ok, think Physics.. hehe

Now, you make a crator.. well, what happens to the dirt there? You''ve got a land mine, it explodes mostly upwards, so it doesn''t create a massive crater like you think it would. Afterall, it''s a waste of explosive force to allow that force to go anywhere but towards the target (even the US govt. knows this..). So here''s what ya do.. you can make two mines. One blows upwards and is more advanced, dealing more damage to opponent, and one goes all over. When you go all over, the created crater is relative to the ammount of explosive force. The bomb WILL make a crater if it''s got enough power, but.. since the explosion is rapidly expanding, it will expand where volume allows. Since the ground is rather hard and the air is more likely to give way, then it''ll most likely push out that way. Now, enough power in little enough time can move things that wouldn''t normally move (in cars, too much compression in the cylinder and ignition can actually blast the top of the engine out the top of the car ). So, you''ve gotta think here.. how big a crater do you want? If you make some serious power to make a crater like that, it''ll have a lip. The ground gets pushed downwards and out, creating a little lip. So as long as you hit the lip with enough speed in a hovercraft, you should make it.
Assuming this place is more advanced than we are, and they''d have to be, then you have to think about things. I mean, what is the impact of an explosion directly under a hovercraft? You guessed it.. it''ll fly up up and away. Now, assuming these people have realized this.. then they can counteract it. An auto-sensing circuit can detect when the car''s being moved upwards and counteract it by reducing the ammount of gravity repulsion the car is feeling. In sense.. it adds weight to the car, pulling it down. Now, the player can pull back on the stick, which overrides this automated circuit, and allows the car to even get lighter than normal, perhaps even pushed upwards This way people can make jumps WITHOUT a jump platform.. they just might have to have a LOT of speed built up to do it. Plus it allows you some measure of control when you run over a mine.. pull up, and you''re all good cause you can set your sights for a landing.. however, if your controls are damaged, you might not be able to push back down to keep yourself from flying way out across the grid and, you might even have the grativy repulser damaged, and come crashing to the ground with mad force

Another way to prevent this is to have the game stop once the course is no longer driveable and penalize the player responsible for this. Then you could have the race re-started, and have only built back 75% of what damage was previously done.. hehe eventually, if the player keeps screwing around, you''ll end up with a track that can''t be driven on really with any enjoyment.. and skip that track This will discourage overuse of exploding a track.. hehe. And it''s what would likely happen in real life (being an avid race fan, they do restart races due to damaged tracks and will skip/return to the track later should permanent damage result).

This sounds like it could be a really cool game if you impliment some of these tactics. Mines today are powerful enough to lift a vehicle off the ground, even big trucks. So if you''ve got a levitated mass and you put a bomb under it.. whee!!!!

J

Yep, Niphty, the land mines will definitely get the crafts airborn

As for your little land-mine physics tutorial, I''m really more interested in maximizing gameplay and fulfilling players'' desire to destroy stuff, so the craters may be unrealistically large. However you''re right about the "lip"... I plan to do the deformations like that as long as it looks good.

I dunno about your destruction penalty/race-restart idea, though. Looking at it from the player''s perspective, I can imagine that being very annoying. I say let the player do whatever he/she wants... I just have to make sure they can''t win the race by pulling such crap.

Thanks for the input Niphty!

Here''s a page out of my philosophy book that could help.
To every disadvantage there''s an advantage.

If you can blow something up to get in the way of a competitor then your competitor could blow it up to get it out of their way.

You were thinking of having bridges that can be blown up which will cause you competitors serious problems as well as your self if you have to cross it again/yes? You could alway shrink the gully under the bridge so it can be driven through (only slower).

Rather than having items in the game (bridges) which are structured as essential they be orientated as merely helpful or advantageous thus eliminating no win situation?



WE are their,
"Sons of the Free"

Also, since generally race tracks are circuts (sp?), you could make the terrain in the middle deformable too! So if the player knew where there was structural weakness, he could blow a hole through to the other side, thus circumventing the obstacle. Cool idea man.

"The unexamined life is not worth living."
-Socrates

Thanks for the input guys

quote:
You could alway shrink the gully under the bridge so it can be driven through (only slower)... Rather than having items in the game (bridges) which are structured as essential they be orientated as merely helpful or advantageous

Paul, you're right, I should try to view any destructable structure in that way. In the case of the gully, though, the track is actually going thru the gully and eventually swinging back around and going over it via the bridge. In this situation, if the bridge is destroyed, maybe I will try to make the gully narrow enough at some point to allow crafts to jump it.

Landfish, that's a great idea, to allow players to make their own shortcuts. I even have a plan that would allow my AI to "learn" the shortcut once a player takes it. Again this raises the issue of players just ruining the race-track... another thing I can do is only allow certain types of terrain to be deformed, i.e., land-mines or missiles can put craters in grass & dirt, but not rock.

By the way, here's a screenshot showing my terrain and its LOD algorithm:



Edited by - Eric on June 29, 2000 6:52:51 PM