Article – Timing events in MediaTracker, Part 1

Part 1 of 4. Written by Alcator.


Unless your track is a full-speed one, you are constantly challenged by the fact that the players may travel at different speeds, and thus may be required to take different paths or perform different maneuvers (like slowing down or jumping diagonally) to successfully pass a certain stage of your track. And what’s worse, there’s no easy way to tell them what you want them to do using custom signs. Because if you place a big sign that says “Fast cars: Left, Slow cars: Right”, how does a player know which case he is?

The MediaTracker can be, to some extent, used to improve the chances of players taking the right path or performing the right maneuvers. However, this is only possible if you take it into account already during the track building process.

This four-part series of articles will show you several ways of dealing with this. Most of the articles will be associated with demo tracks that show each of the ways, so you can see the limits and advantages.

The limits of MediaTracker

There are two things the MediaTracker doesn’t know: the speed and the direction of the car. If you place a triggering cube to a point where you expect the cars to go from East to West and the car somehow manages to enter the cube from West to East, the events that happen in the MT clip may confuse the player (such as telling him “keep turning right” when from his point of view, the curve is turning left).

Also, you have no information about the car’s speed, so instructions like “Slow down” or “Full speed” may in some cases be counter-productive, as following them may result in failure.

The features of MediaTracker

There are several features (behavior rules) of MT that you need to be aware of:

  1. If the player respawns at a CP, any running MT clips are stopped and reset, and can be triggered again. Placing a triggering cube right at the CP means the clip gets launched if the player respawns there.
  2. An MT clip cannot be re-triggered if it was the last clip triggered, no matter if it is still running or already ended. So, if you have two loops lined up and you want bumper-camera for each of them, you have to trigger some other clip between them if you want the same camera clip to be triggered on the second loop as well.
  3. Triggering a clip will stop any running clip immediately and start the triggered clip. This can be used to switch off clips when they are no longer needed.
  4. It is possible at very high speeds for the car not to trigger a clip if the car passes through an edge or corner of the triggering cube. This is very bad and can only be countered by placing two or more triggering cubes right next to each other so that the car is “bound” to go through. However, this may cause problems in some cases as well (as the additional cubes may be “touched” by the car going on another floor or jumping across the area etc.

Note: This whole article assumes that your track contains so-called “speed requiring section” – such as a long jump over some bad obstacles – and that you want to tell those racers who are not fast enough for that stage that they have to go “around”. If any of these conditions is not met in your track, then you don’t have to do any of the stuff here. Keep in mind that while it is fair to warn player about extremely unusual speed traps, it’s not needed to tell him “attention, sharp curve ahead” if he can see it in advance – players are not stupid and they do know what a brake key is.

Every time you theorize, God kills a kitten

Let’s first look at a picture. It shows a technical coastal road that ends with a T-intersection. The idea here is that if you navigated the technical part perfectly, you should have enough speed for the faster path (through the jump ramp on the right); while if you are not fast enough (because you respawned or crashed before the T-intersection), you should take the left path that, while longer, is easier to go through.

Timing events in MT, Part 1, Image 1

There are also two curves drawn through the technical part – one green, showing an “ideal” path, and one red, showing one of possible “bad” ways of going through (the edge bumps surely cost a lot of speed, right?).

Let’s now draw an approximating graph of both paths, which would show how far from the Checkpoint the racer is as the time goes by:

Timing events in MT, Part 1, Image 2

As you can see, in time T0, both cars are at the same point – the checkpoint. Now, since the green car goes on the ideal path and constantly accelerates, his distance from the CP increases parabolically.

The red car, however, is 1) going slower (maybe he respawned in the CP?) from the very start, and he also loses speed on several occasions, resulting in even worse speed.

The green car gets to the intersection at T1, while the red car gets there in T2. The temporal (time) distance between these two moments will be very important for us in the following chapters, so you need to understand how it evolves perfectly.

To make this distance (between T1 and T2, between the time the best racer and the slow racer needs) greater, the following “tools” can be used:

  • build a difficult technical section which requires occasional slowing down (or letting off the gas)
  • build a wide curve where worse drivers slide, while good drivers keep accelerating, or where worse drivers take needlessly wide turn, while good drivers keep the radius smaller

The reason why you will want the distance between the two moments big enough is that in that time between them, things will be happening that will be telling the slower drivers to take alternate routes, and you need to give them time to both read/see them and react to them. There’s no use in telling the player “Go left!” for 0.1 second, if he would need at least 2 seconds to actually turn.

This also means that the shorter/smaller the area in which fast and slow cars are “separated” is, the smaller the difference will be. It may sometimes be only possible to differ between those racers who went through the checkpoint and those who respawned in it (as that usually generates big temporal difference).

After this theoretical introduction, let’s describe the first method and show you a practical example:

Method A: The delayed instruction

(This method is illustrated in the first Demo Track at the first checkpoint)

This method works like this:

  1. Players pass a point (usually a checkpoint) from which time is measured (by an MT clip that starts running silently).
  2. At some distance, there is a splitting point (an intersection or widening through off-road etc.
  3. From this splitting point, two exits lead. One of them leads to the “speed requiring section”, the other leads to the detour around it.
  4. At the start of the SRS there’s an empty clip’s trigger that switches off the time measuring clip. If the racer reaches this point fast enough (before anything visible happens in the time measuring clip), he doesn’t even have to know about the time-measuring clip running.
  5. However, if the racer takes too long to get beyond the splitting point (which, usually, means he doesn’t have enough speed for the SRS), one or several events in the time measuring clip provide navigation instructions, telling him to take the detour.
  6. Upon entering the detour, another empty clip’s trigger switches the time measuring clip off.

Now, let’s go through the method in detail.

Find a point well before the SRS from which the player has to work on his speed to be able to pass the SRS successfully – i.e. a point from which the car accelerates. Be careful so that there are no places between this point and the SRS where the speed is lower, because that might allow a car that is slower “now” to still make it through the SRS correctly.

Alternatively, and that is the style used in the demo track, find a point where skilled drivers have significantly higher speed due to perfect driving through some previous section. This speed gain will then let them continue towards the SRS faster, thus it will allow them to get to the SRS sooner.

As mentioned above, you’ll need the slower drivers to be significantly slower (or, to arrive significantly later) than the fast drivers.

Place a triggering cube of a clip that will be referred to as “Navigation Hints clip” (NH clip). Record an MT ghost of a perfect ride through the SRS section. Next, check for how long the NH clip runs before the perfect driver gets to the beginning of the SRS section. This will be the time referred to as “Minimum time”.

Then, re-record the ghost, still through the SRS section, but try to drive a little “worse” – such as try letting off the gas for a split second during the pre-SRS part. What you are trying to do now is find out the slowest car that can still make it through SRS OK. The ideal case would be to find out the speed at which you do pass the SRS, but with serious trouble, like landing on the landing ramp with two wheels off the road, or landing so roughly that you flip and lose a lot of speed.

When you record the “worst” ghost that can still make it through SRS somewhat OK, go to the MT editor and once again check how long it take him to get to the beginning of the SRS. This we will call “Maximum time”.

Now, let’s just for illustration assume that “Minimum time” is 2.50 seconds and that “Maximum time” is 3.30 seconds. This means that we will want to make sure that anyone who goes through the pre-SRS section slower than in 3.30 seconds will see the “Take the detour” instruction. However, if we timed the instruction so that it only appears after the NH clip is running for 3.30 seconds, those who take 3.35 will only see a flashing text appear for a brief moment, not able to read it.

Therefore, we will time the instruction so that it appears at 3.00 second (or perhaps 3.10); this will cause it to flash unreadably for those who can still make it through the SRS section, but those who definitely have to take the detour will see it for 0.3 seconds, which is somewhat enough (or, let’s say, on their second attempt, they will know that if that text appears, they have to take the detour, and will be on a lookout for it).

Finally, you should make the “CP respawn test”: Record a ghost (or play the track) and try CP-respawning in the CP at the beginning of the pre-SRS section (where the NH clip starts running). You should see the detour instruction well before the splitting point, so that those who respawn know they need to take the detour.

This is also the reason why you need to make a big enough time gap between the players; if Minimum time is 1.00 and Maximum time 1.10, this method won’t work very well.

Note: The demo track “Crucial Skills” shows much more than just telling slow players to take the detour. It shows how to place instructions on re-use parts so that they only appear for those who travel in a particular direction. Also, the way the helping maps appear near the turning point CP, is worth noticing. The track is not password-protected, so feel free to look at its guts and see how it’s done.

In part 2, we will look into a way to make navigational tips smoother and less “ambushing”. The demo track for next part will be a wild Island track!


6 Responses to Article – Timing events in MediaTracker, Part 1

  1. Aaerox says:

    Wow Alcator! This article is really great. 🙂 Even the “not-so-skilled” players will understand it. And this MT work is quite hard to manage, if ou don’t have a instruction like that.Many players don’t know how to make such things. In fact, I didn’t knew this method until now. 😀
    So thanks for that awesome article. I’m looking forward to the next parts of it. 🙂

  2. alcator says:

    good to hear that, Aaerox; I promise you this serie will be getting better and better with each additional chapter.

  3. Bye Tom says:

    I haven´t read all, but here is another thing you can do, you can make a mediatracker which says: Over 450 km/h Right Under 450 km/h Left!
    Anyway, your idea which you describe in the article is much better! Thanks!

  4. alcator says:

    Bye Tom: Yeah, the problem with telling the player speed threshold is this:

    1) It’s not easy to look at your speed meter
    2) The value usually changes quickly and it’s virtually impossible to tell whether you had the required speed when the message appeared, or if you gained it later…

  5. […] – Timing Events in MediaTracker, Part 2 Last week, we learned how to add an MT navigation tip that only displays for slow drivers – those who need to take a detour around Speed Requiring Section […]

  6. Emil Hjelm says:

    That’s a great idea with the delayed instuction! Well, the reason that I say it is ’cause I used it in a track of mine in TMN a loong ime ago ^^. Anyway great article!

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