[Terry]

Until recently, this is one aspect of RPG design that I never gave a second thought to: The graphical effect that usually accompanies transition into a battle (in particular, in FF games). My field view is 2D, but my battle engine is 3D, and at the moment I'm trying to literally go from one to the other seemlessly when a battle starts.

When I fail to do that, I'm probably going to go with some kind of FF7 style battle swirl.

Anyway, I was just curious - does anyone out there know how they did it? I've got a few ideas for things to try - but I remember seeing a Net Yaroze game that had exactly the same effect, so I'm wondering if there's a specific algorithm for it or if this is something that other people have thought about? (Better than completely reinventing the wheel, if you know what I mean)

Also, has anyone ever tried to do something new and interesting on this front?
_________________
http://www.distractionware.com

[Nephilim]

Typically, those swirls are done by just re-copying the current view buffer over and over again onto the same buffer with some sort of transformation.

For instance, you could take the current frame buffer, lay a 5% white wash over it, and copy it back onto the same buffer 10% larger with 25% opacity. Do this multiple times, and you'll get a zoom-blur-to-white effect. (The numbers are just off the top of my head, so you'd have to tinker with them.)

Check out the "demo" scene for more tips and tricks for fast and dirty visual effects.
_________________
Visit the Sacraments web site to play the game and read articles about its development.

[RuneLancer]

I may've missed it, but which API are you using? I would guess the typical OpenGL or DirectX ones, seeing as you mentionned 3D, so this idea should work.

Project your map from a top-down view with billboarded sprites. This will give the illusion of 2D `…-la OpenGL's orthographic projection mode. However, when a battle occures, rotate the viewpoint from topdown to bird's eye or whatever the battle view will be (the sprites will follow automatically, being billboarded), and there you go: from 2D to 3D. This, of course, assumes the battle map reuses the game map.

Otherwise, if a transition is really what you want, most of my experience lies in OpenGL. You could try rendering to a texture and doing stuff with that (multiple textures would allow you to have, say, the screen-shattering effect of Xenogears' battle transition). Or you could render to the accumulation buffer, rotate the scene slightly, render again, etc stacking up renders to give a swirling effect.

Implementing radial blur effects and "zooming" the view into the map is another potential solution.

Also, don't forget not clearing the color buffer will grant you a number of options if you render to a texture and only draw with very little opacity (GL_BLEND). Zooming and rotating the view will cause images to "stack" if you don't clear your color buffer first because of the transluscency.

Dunno how these would apply to Direct3D, I have less experience with that. ;)
_________________
Endless Saga
An OpenGL RPG in the making. Now with new hosting!

[Terry]

I'm just using Allegro, so the 3D in the battle engine isn't really 3D with polygons and things like that, it's just a cheap Mode 7 display thingy - anyway, I think I'd rather just do a battle swirl anyway, for the classic RPG charm of it.

At the moment, I'm just doing a spin/zoom thing, in pretty much exactly the way Nephilim described how he would do it. What I really wanted to know, though, is *exactly* how did FF7 do it? Because I've seen the same effect down to the pixel in another indie game, I thought there might be some documented algorithm somewhere - I guess it doesn't really matter though...

(Even though I'm getting very near a point where I can start making content for my game, I keep getting sidetracked by things like this. Anyone else ever have this problem?)
_________________
http://www.distractionware.com

[tcaudilllg]

I remember Eidos didn't even try to replicate the FF7 swirl on the PC. Instead they just opted for a spiral blend and zoom. A big letdown.

I think part of the way FFVII does it is random. There are actually several "swirl" patterns that I've discerned.

[RuneLancer]

In reply to that edit, I get that pretty often. I have this bad habit of spending too much time on tiny things.

Of course, in the end, it makes the game feel more "polished" but it's a terrible way to use your developement time if there are more important issues to tackle..
_________________
Endless Saga
An OpenGL RPG in the making. Now with new hosting!

[js71]

Ever played 7th Saga? It had an interesting seamless transition from 2d to a mode 7-style battle system.

[Terry]

Oh, I remember that! That battle engine isn't that far away in visual appearance in what I'm working towards, only with movement.

Anyway, problem sorted, I've gone with something really simple :)
_________________
http://www.distractionware.com