Advanced FRED2 Retail Help

Mission Design

How long does a ship take to recharge jump engines after a jump?

The simplest answer is as long as you want it to. There is very little hard data on this. It depends on the ship.

SEXPs

What is the difference between ai-waypoints and ai-waypoints-once?

AI-Waypoints-Once does just what you'd expect. The ship follows the way points you've given it and then comes to a rest at the last one. With AI-Waypoints however upon reaching the last waypoint the ship turns and heads for the first waypoint and begins the cycle again. This makes it very useful for setting up patrol routes etc.

Can I disable Alpha 1's subsystems?

Yep. Fred2 will complain at you but it will work.

How do I make a ship jump out at a certain place (e.g. a jump node)?

This depends greatly on the ship. Capships (or any ship that the player can't make jump out) can be done fairly easily. This is one way. You have to place a waypoint in the middle of the jump node. You then make the ship leave when it reaches a suitable distance either from the ship editor or by changing the ai-goal as shown here.

If you're trying to stop Alpha 1 or a ship that Alpha can order to jump out requires a little more work. First you need to prevent the ship(s) from being able to jump out. Then you need to make it so that the ship can only jump out within a certain distance of the node.

The second event activates the jump engines when alpha reaches 500m from the centre of the node. The third event deactivates the engine if alpha leaves the area around the node. you'll need a repeat count on the second and third events or alpha 1 might become stuck in the mission. You might need to alter the distances too since I haven't checked them (Last time I checked around 700m is a better choice).

I noticed you are using never-warp in the above example. Why not break-warp?

Never-warp prevents the ship from leaving until the allow-warp order is given. Break-warp merely breaks the jump engine. It can be fixed by the fix-warp SEXP but it can also be repaired by a support ship. This of course means that the player could spoil your carefully crafted "leave only at the node" mission simply by rearming. For this reason Break-warp should only be used when there are no support ships allowed in the mission (or if you want to create a mission where you say that something has broken the players drive and he needs a repair).

What is the difference between Ship-Invulnerable and Ship-Guardian?

Ship-Invulnerable means that a ship can't be damaged by anything. No matter what happens the ship will remain at 100% (or whatever the damage was when it was at when the SEXP triggered). Ship-Guardian allows a ship to take damage until the ship reaches 1%. After that the ship becomes invulnerable. Careful use of both can fool the player and prevent him from realising that the ship is protected (A wing of ships at 100% at the end of a mission is a big sign that Ship-Invulnerable was used while a wing at 1% is just as obviously a sign of Ship-Guardian's use.)
FRED2_Open has a third SEXP Ship-Guardian-Threshold that allows you to set the point at which a ship becomes invulnerable to something other than 1%.

How do I make a message come from a ship that isn't actually present?

If you look at a mission in FRED you'll notice that all orders from command are actually coming from #command. The # symbol tells FS2 that it's not coming from a ship that is actually present. Simply make the message come from #Whatever.

How do I make a Red-alert only occur when the player jumps out?

Easy. Just use an event like this. Replace the -true in the first event with whatever conditions you want to use to make the mission red alert.

The key-reset is needed to make sure the jump out isn't triggered 4 seconds after the Mission Complete event becomes true if the player happens to have pressed ALT-J at some other point in the mission.

Variables

Most beginners regard variables as one of the most confusing parts of FRED. In actual fact they aren't really that tricky. I was using them since the first mission I ever FREDded. What confuses most people is that when they see them being used it's always in big complicated events so they get lost. I'm going to try to explain simply how to use them.

What is a variable?

Since most FREDders aren't from a programming background the first thing that needs explaining is what a variable actually is.
One simple way to think of a variable is as a box. The box has a name written on the side of it (the name of the variable) and inside the box you can put a single number (The value of the variable). String variables contain a word or sentence rather than a number but I'll explain those in the FRED2_Open section as number variables are easier to understand and string variables are of very limited use in FS2 Retail.

How do I make one?

You create a new variable by choosing add variable from the right mouse menu in FRED. This opens the Add Variable dialog box which allows you to name your variable and give it a default value.

When you make a new variable you always create it with a default value. It's impossible to have an empty box. There is always a number inside the box (although the number can be zero!). FRED will remind you what this default value is. Whenever you use the variable you'll notice that it's followed by the default value in brackets. While the mission is running there are only two things you can do with a variable. You can either open the box and take a look at the contents, or you can throw away the contents and put something new in its place. Every single time you see a variable being used in a SEXP no matter how complex it is it will be doing one of those two simple things. (Some events do both but each SEXP within the event can only do one of those things.

So how do I use them?

With me so far? Good. Okay, so a variable is a box for putting numbers into. What use is that? Well quite a lot you see. Because you can place this box anywhere in FRED where a SEXP is using a number.
For instance take the event on the left. You can quite easily change the 0 into a number variable if for some reason you wanted to.

One important thing to understand is that every time you see a variable being used in this way you are opening the box and taking a look at the contents. Whenever a variable is substituted for a number in a SEXP it is always being looked at. No matter what the SEXP does the variable will remain unaltered.
There is only one SEXP that can change the value of a variable and [V] did us the favour of giving it a pretty unambiguous name, Modify-variable.

Modify-variable does only one thing. Throw out the contents of the variable mentioned on the first line and replace it with whatever the second line is (or whatever the second and subsequent lines calculate to). In the example given to the left the contents of NumberVariable will be thrown away and replaced by zero. Remember only the variable in the first line is ever changed.
If you've noticed that the default value is zero and you're wondering why I'm replacing it with zero it's because some other event may have changed the value to something else. Remember that the value you see is the default. FRED has no idea what the variable can be at any particular point in a mission because it depends on what events have triggered).

The simplest and most common use for a variable is for counting the number of times something happens. This is done by making an event that says when something happens look at the number in the box, add one to that number, put that new value in the box. The SEXP to do that looks like this.

The modify-variable SEXP tells you that we are going to change the contents of a variable. The next line tells us that the name of the variable is NumberVariable (It also tells us the default value is zero). The line after that tells us what value to set NumberVariable to. In this case it doesn't give us a number but instead gives us a SEXP that has to be evaluated to find out what the desired number is. The SEXP is simply the addition of two numbers. The first number is the contents of NumberVariable and the second value is one. So after the SEXP is finished we'll have added 1 to whatever the value of NumberVariable was (Which you may remember was what we were after!)

Alright. I can use them. I still don't get what I'd use them for?

Okay so now you now know how to make a counter. What use is that? Well the FRED2 Walkthrough has a good example of a counter. In that mission you have 4 troop transports attempting to capture an Orion. The transports will dock with the Orion. Spend a little while disgorging troops and then undock. If two of the troopships manage to successfully dock with the Orion then it is captured by the enemy forces. In the walkthrough they used variables as a way of achieving this. Basically they defined a variable called DockCount and added 1 to it every time one of the troop transports managed to successfully dock. When the value of the variable was 2 then the Orion could be captured and a simple when DockCount = 2 type event could be used to test this.
Still with me? Okay. Let's try something a little more advanced. Although the walkthrough shows a good example of how to use a variable it's not the best example as it could have been made using normal SEXPs (basically a big OR checking that two transports made it). Many FREDders would feel more comfortable doing this rather than messing with variables so lets suggest an example that can't be done without variables.
Lets say that you want to say a certain number of marines board the Orion before the NTF forces could succeed in taking it over. Let's say that it doesn't matter if the troop transport managed to get undocked safely afterwards or even if they get blown up while landing troops since they are in battle armour and the ones already on the destroyer will be fine (although those still in the transport are toast). All that matters is the time the transports managed to stay docked to the Orion.
Now that is pretty much impossible without variables. With them, well it's not easy but it's possible.

First you set up a variable called timedocked (with an initial value of 0). Then you set up a repeating event for each transport that looks something like the one on the left (Lots of repeats, repeat every second).

Basically this event waits until the transport has been docked for 10 seconds and then adds 1 to the value of TimeDocked every second until the ship undocks or is destroyed.

You'll need copies of this event for Transport 2, 3 and 4.

Then you have an event like the one on the right
That event triggers whenever timeDocked reaches 100 seconds regardless of whether each ship stayed docked for 25 seconds, one ship managed a full 100 seconds or any other combination you can think of. Replace the do nothing with whichever SEXPs you feel depict the NTF taking over the Orion and you're done.

As you can see there is no way you could do what we have just done without variables. With them we've done it in just five events (One for each transport plus one to check if the Orion has been captured). It is this sort of power that makes variables worth the trouble they are to use. I've seen missions that have hideously complicated logic to them that I could have solved in one or two events by using variables. Eventually missions reach the kind of complexity where it's much easier to just try to learn how variables work than it is to try to write the mission without them.

Arrivals And Exits

I've set Beta and/or Gamma wing as a reinforcement. Fred keeps complaining at me.

Ignore it. The ships should work fine in game. FRED doesn't like either wing being reinforcements so you can get rid of the error (if it annoys you) by setting them to some other wing but either way it will work fine in the game. Remember that doing so will prevent the player from arming those ships during the game as only ships in Alpha, Beta and Gamma wing appear in the loadout screen.

How do I make reinforcements only appear later in a mission?

Same way you make other ships appear later. Set the arrival cue. If you do this for a reinforcement unit it will remain greyed out until the arrival cue becomes true. After that the player will be able to call the ship in (don't forget to remind the player that the reinforcements are now available)

Events & Objectives

What is an invalid objective and how does that differ from a bonus objective?

When making objectives in the objective editor you may have noticed the little Objective Invalid tick box and wondered what it does. To explain let's take an example mission. Suppose you're FREDding a mission where you're going to destroy a Moloch corvette. When the mission starts however you find the Moloch taking on supplies from a Demon class destroyer. Command order you to ignore the Moloch for now and concentrate on the Demon. Now look at your objectives. Having the destruction of the Moloch as a primary goal while the destruction of the demon is a bonus seems ludicrous. In addition to this the Destroy Demon objective will only appear on the objectives list after you have destroyed it.

This is where invalid objectives come into their own. The game completely ignores the objective until an event using the validate-goal SEXP is triggered. After this the game treats the goal normally. So basically you've suddenly made a Destroy Demon primary goal appear as if by magic.

Goal validation doesn't end there though. Just as you can validate goals you can also invalidate them. For instance at the moment destroying the demon and the Moloch are both primary goals. If you fail to kill the Moloch you won't get the full victory music even though you did better than the mission briefing expected of you. What you can do in this case is use the invalidate-goal SEXP to make the Destroy Moloch goal invalid. The game will now ignore it.
If you're really sneaky you can even have an invalid Destroy Moloch secondary goal as well as a primary one. Invalidating the primary while making the secondary valid will make it look like the Moloch's destruction has changed from being a primary goal to being a secondary one.

It's worth noting that bonus goals can also be invalid too. You could have a Destroy Cain bonus which only becomes valid once the Moloch and Demon have been destroyed or have departed. In that way you get a bonus if you destroy all three but get shouted at if you ignore the Moloch in favour of the Cain.

Voice Effects

How can I make voice effects?

There are two main programs used by the FreeSpace community. Goldwave and CoolEdit The programs are fairly easy to learn how to use. Goldwave is shareware but it will only start to nag you after 100 operations which should be enough to allow you to make a few voices.

How can I make Vasudan effects?

Goldwave has a rather cool mechanise special effect that is pretty close to the one used in the game.

Medals And Promotion

How do I give out a medal?

Medals are given out by the special grant-medal SEXP. Don't bother looking for it on the list unless you're using the SCP version of FRED cause it isn't there. What you need to do is create an event and then manually change the do-nothing into grant medal. You can then pick which medal you wish to grant.

How do I put ships in the tech database?

Using the tech-add-ships SEXP. As with the grant-medal SEXP you have to type this one in manually unless you're using the SCP version.

Cutscenes

How can I have new cutscenes in my campaign?

Short answer. You can't. FS2_Open can do it but retail can not.
Longer answer. FS2 retail only plays movies in the MVE format. MVE is a proprietary format owned by Interplay and there are no tools officially available which will allow you to use it. You can make the game play an existing FS1 or FS2 .mve file by simply specifying it in the campaign editor but to add anything new would require the use of one of the illegal programs floating around the net which will allow you to encode MVE format movies. I once found avi2mve but I've got no idea where you'd get it from if you wanted it now.

Debugging and Weirdness

Since certain problems only show up during debugging or seem to defy all logic I'll put some of these problems here

I have an event that is supposed to occur when a ship is 50% damaged but it isn't happening

The problem might be that you have an event like the one on the left in your campaign. The problem with this event is that it only comes true when the ship hits 50%. However certain kinds of weapons don't cycle the counter down but change hits-left immediately (e.g. from 51% to 47% without passing through the intervening numbers). The result is that the event is never triggered since the ship was never 50% damaged. This problem is easily solved though. Instead of triggering when the ship is at 50% the event on the right triggers as soon as the ship is less than 50%. Thereby avoiding the problem. (I suppose I should have set that to 51% actually so that the event would trigger when the hull was 50% rather than 49% as it is now)

I still can't get an event in my campaign to work

The first thing to find out is if the event is happening at all. Messages are the simplest way to do this. If the event has a message and you aren't seeing the message then it isn't being triggered for some reason. If there isn't a message add one and see if it goes off. If it doesn't add one to events that it is dependant on and see if they are triggered. By using this method you can trace the SEXP that isn't working.

When the mission starts the clock says it's 2 minutes into the mission. Other weird things have also happened.

This is the infamous player entry delay error. It is caused by having too many ships in the ships.tbl You can't really do anything about it except reduce the number of ships in your table. Once you've trimmed down the number of ships in the table you can salvage your mission by opening it up in notepad. Look for a line that says "+Player Entry Delay:" The number afterwards probably says something like ~120 Change that number to 2.0000 (everyone says 0 but when I looked at working missions of mine the number there was 2) and your mission should work.

I've entered some text into FRED and it looks fine but then it disappears when I save

Was the text within quotation marks (")? Due to the way FS2 mission files are set out FS2 views the first quotation mark it sees as the end of the message and doesn't parse anything further. Just don't use quote marks in briefings, debriefings or messages and the problem should go away. Don't use semi-colons either for that matter.

I've entered a message in FRED and it looks fine but then it disappears when I choose another message and then go back. The message properties I set have also been wiped.

This is due to a bug in FRED. You should only edit messages when that message is highlighted in the message list.

I've written a mission but all the capships seem to be strangely invulnerable/My shots are going straight through ships.

This is another of the problems caused by Battle of Endor Syndrome. Basically you've tried to make your mission too big and FS2 can't do the collision detection on every new object the game creates (like laser bolts and beams). As a result these things don't collide with anything and simply go straight through capships without damaging them. The only solution is to scale down your mission or use FS2_Open which is slightly better at handling this sort of thing.

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