Author Topic: FFVII Battle and Data Errors: What they mean  (Read 7742 times)

Bosola

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FFVII Battle and Data Errors: What they mean
« on: 2010-12-06 02:37:28 »
As modders working on FF7, I'm sure we all come across a variety of cryptic, difficult-to-resolve errors - not least in battle scenes. Whether that's the dreaded Data Error, a glitched background, or completely invisible creatures, we've all been puzzled by them from time to time.

Because debugging a mod can be so time-consuming, I want to document and explain the various errors that battles can throw us, and hopefully speed up everyone's bug-resolving efforts.

The Data Error: Scene XXX / Code : YY

XXX is the encounter number, in decimal rather than hex. If you use Proud Clod, you'll know these as formation numbers. Use the formation tab and look at the 'formations' - those are the numbers we're talking about. If you convert the Scene number into hex, you'll know exactly which formation (and attached enemies) is causing the trouble. That should save you time right from the off.

Now, YY is a bit less obvious. So far, I know that

32 - Can mean: Creature uses an animation that hasn't been 'authorized', i.e. isn't listed in the "Assign Animations" dialog within Proud Clod. Use Proud Clod's 'check animations' feature to help resolve this.
38 - Can mean: Unknown. Linked to Kernel AI problems?

I didn't get a scene number for my data error! All I got was the message 'Scene: #$'. What does that mean?

Are you using a multi-part spell (eg a spell with additional effect 18, 'Perform X after completion')? You may have forgotten to authorize the animations to the second part of the attack.

Help! My emulator crashed when a monster used a custom attack!

This, alas, is common. Certain attacks are linked to certain actors and backgrounds. For instance, Supernova relies on the Safer Sephiroth background.

There's little you can do about this one.

FF7 just went black when a battle started. What's going on?

You may have deleted the scene being called. Double-check this.

The monsters just sit in their idle animations. My party's time bars fill, but when I select an action, nothing happens. There is no data error.

You may be performing an enemy attack in the wrong 'type'. Let me explain

Normally, to attack, you push two values onto a stack and use opcode 92, eg

60 20
61 0111
92

That 20 is significant. It tells the battle engine that it's to look in the list of enemy attacks - or, in FF7 terms, it sets the attack 'type' as an enemy ability. If you see this glitch, you have used an incorrect 'type' (eg not 20 or 24 for enemy attacks, 0 for commands, 1 for spells, etc...)

My monsters just don't do anything?

Are you sure you haven't deleted their Main scripts, or written AI that always chooses inaction?

I start a battle, and the background gets messed up - as though the colours are 'inverted'. No entities appear, and the game freezes

Alternatively, The enemy model won't appear!

This can happen if your general battle flags are incorrectly set. Not much is known about these flags, but they typically take the forms FFFD and FFED. There are some other, rarer flags, but they're typically associated with the 'quirky' boss battles - such as those including multipart enemies, multiple parties and other odd behaviour. They presumably interact with various battle engine settings for these 'special' battles.

My monster doesn't appear!

Your monster may have the enemy battle flag FFE6FFFF, used by Reno's Pyramid, Waterpolo and all other enemies that don't appear until 'summoned'. Reset to FFFFFFFF to force the creature to appear when the battle opens.

The battle begins, and the background starts to appear - then the game freezes!

This can happen if the battle calls an enemy that doesn't belong in the scene. Check your formation data.
« Last Edit: 2011-01-28 18:51:34 by Bosola »