Hi!
I have a theory to how to get Split Screen in JK without chopping the room or the people in half. The only reason I'm not showing it is because I haven't been able to tame the HOM completely yet. Could you help?

I have a room, and a little hole in the wall, and chop the adjoin in half and deactive the 0x1 adjoin flag on one half. Then I do the same in another room, but block sight on the other half. Then I have a cog flip between the 2 cams with a very small delay like 0.01. Yes, this would also chop the framerate in half. But hay, who'd like to use this? And, maybe, even perhaps make a screen surface "render" a part of the level.

What do you think?

/Edward

I suppose quite a bit of things would be possible if JK renders at least one frame when a new camera gets focus. Say for example, you had a camera in a sector, facing a white wall.

Then you switch to another camera in another sector, but this sector has some HOM in it.

In theory, if JK renders at least 1 frame when switching to a new camera, JK will "paste" the sector with HOM, over the already rendered white sector.

The cog might look like so:



In theory it should work like "Layers" with the HOM being your transparent color.

(I ain't testing it :p)

Interesting...

You could make a translucent archi 3do in front of the camera on the oposite sides of each respective camera, so it wouldnt be limited to one level.

It would probably be unstable though.

I don't think it'd steal that many FPS, maybe as many, as camera switches you have?

Huh, thats a pretty interesting idea there...making the nature of HOM work for you.

I always wanted to make a picture in picture system with JK (this doesn't make it any more possible, I'm just saying...:D)

if you have the HOM effect, it is just because JK isn't drawing anything there, so whatever was last at that spot on the screen will stay there until something else gets drawn. As long as you don't draw anything on one player's side while the other is rendering, the timing may not be that much of a problem.

Edward, that is a brilliant idea. I might have to test this idea this weekend.

I've read this thread about 3 times now: I must be stupid. What are we talking about? Can I get a bit more of an idea of what we're talking about, so that I can perhaps lend my knowledge, or at least try or steal whatever this is?

JediKirby

The HOM effect takes an image and keeps it there. If we could keep a half screen image on each HOM side and move a camera around to make the HOM of an old scene (where the other camera would be) half of the screen, and the other half be a current image, pulsing between, we might be able to get a split screen view.

Might this effect also work on any designated surface within a map? In other words, might this open doors for portal effects, like in the Unreal engine? (Portal skies, "Video" screens displaying the action within another area of the map, true reflective surfaces, and even Warp Portals where you can see into the area you're warping too)

Please stop me if I have completely the wrong idea... I could get way too excited over this... since this would be a discovery much more useful than for split screen gameing.

Quoted from halucid:
"Video" screens displaying the action within another area of the map

My first thought when I saw Edward's post was video screens. I am planning to test the technique by attempting a hud-like rear-view camera. This way, it can be implemented as a mod, so others can see it in action as quickly as possible.

If the test is successful, then I will try a video screen.

I fail to see how a video screen or PIP would be possible.

HOM effect occur only with level architecture, which cannot be attached to the player. And I know of no way to cause a 3do to create HOMs effects....is there one?

TV screens were my first thought, but they aren't possible either that I'm aware of. This doesn't give us the ability to just draw a dynamic image on a surface...its really just leaving an image behind and not drawing over it.

This effect requires you to control the POV of both sides and use level architecture to create alternate dead spots.

I can think of a way to make portals like in unreal that *may* work however. But I'm still working it out in my head and it seems like a longshot. I think it would cause flickering.

This is still a pretty cool idea though. Almost like the use of HOM for a blurry drugged out effect that some one did...I think Gris

Well? Spill the beans, my man! Start a new thread, I'm dying to hear it.

You just have to flag a 3do as architecture (or make it a walkstruct, I can't remember which) and give it translucent/transparent surfaces to make it HOM.

Someone used this method to make a predator effect about 5 years ago, I tried something similar about the same time and it worked perfectly.

Lol, well there may be something that will cause this to not work...its a theory based on a theory.

I've attached an image. You've got the place you are and the place the portal leads you too. When you enter the sectors that can view the portal, you capture the players look vector and pos. Using a set of offsets for X/Y/Z you get the relative pos of player if he were in the HOM dummy sector attached to the portal section.

You create a ghost I guess at this pos and look vector. And you start running a fast pulse, swapping the players view between the player, and the dummy player. You teleport or create/destroy the ghost at every iteration to keep the relative position of the ghost in the correct place.

As it swaps between them, it should only redraw the stuff you need. The HOM surface in the sector you're currently in, should be drawn over with the view of the portal sector...and since that dummy sector attached to the portal sector has no other walls that are not HOM...the 'real' walls on your side should remain drawn on the screen. It cycles through to keep the other side updates and to keep your view position correct.

This will of course take some cog work, but it seems feasible to me right now.

Well crap, that opens up a lot of possibilies....

From El Scorcho:
Also from El Scorcho:

Am I missing something? If the stuff that is being redrawn changes between successive swaps, then video screens are just another version of the method El Scorcho just described. Instead of the 'ghost' room being a duplicate of the room the player is in, just make it where a camera is. Then, just use a 3do or something that HOMs everywhere except where the video screen should be. A bit complicated, but should be possible, if the technique works at all.

El Scorcho, that is one of the things I had thought of when thinking of Live Feed camera and screen.

Boy, I'm getting famous here!

And, I'll give you something to start on. The attached ZIP holds an experiment... It has gone somewhat wrong... The second scene is not visable... Could someone help?

/Edward

Well, I don't think that would work. You see...the idea of the portal is to make a room appear to be on the other side of a doorway that isn't actually there. The idea of a camera on a single surface is different...you don't want the room on the other side shifting around depending on the angle you view it...you want an image pasted onto a surface.

Its hard to explain, it isn't even easy to visualize. But when you look dead on at your TV...you see an image. When you look at the TV at an angle, its still the same image. When you look through a window, its not the same image.

I'm not sure we're on the same page with the 3do...that opens up PIP possibilities...but I don't think it helps this to much. The TV image is skewed if you look at it from one side right? How are you going to draw an area on the screen with that skewed perspective in the first place? With PIP, there's no skewing of the image involved, its stuck right on the players HUD and will always be the same size and angle.

This is giving me a headache!

There's no way to create HOM with 3do's. Translucent 3do's always show the architechual surface behind it.

The only time HOM is created is when a surface (or invalid adjoin) is not being rendered there by creating a hole in the level. There's nothing to render so the JK engine pasts a copy (or multiple copies as needed) in that location of that area of the screen, to close/fill the hole.

Again, 3do's can not do this.

Well, I don't know about the 3dos causing effective useable HOM in this instance or not. Although, what you said makes sense. But I'm hoping your wrong.

But technically friend (I'm just being a nitpicker here) JK doesn't paste anything...rather, its never told to draw anything new in the HOM areas and thus just leaves what was previously rendered on the screen.

I'm trying all sorts of ideas as I post, and yea, it's REAL hard to visualize. >_<

*passes Scorcho the bottle of Excederine Migrane*

If you're interested in what I've come up with so far:

Slap this in Episode: http://www.hellraiser64.com/Pics/CamTest.gob



This is the end result, there's a HOM hole in the wall, and whats displayed is the view from a camera in the corner of that same sector. But it flickers between the player view, and that one camera, so thats what I'm messing with now.

3dos can HOM, I can't remember how but they can.

I once made a Ninja skin and flagged it in a certain way, the skin also had translucent surfaces. Whenever you moved a hom effect would make you more visible, when you stopped moving you became almost became invisible.

I also once had a problem once where a train 3do I placed in a level wasn't being shown and in it's place was HOM in the exact shape of the train.

I think there's a flag somewhere that causes JK to treat a 3do or 3do surface as level architecure, this means that as soon as the surface becomes translucent, it will HOM.

Not a 3do, but a thing. Add 0x8 to it's Thing Flags.

So 2D portal effects (TV screens) are at least nearly possible, as Hell Raiser has proven... but not 3D portals (windows, warp portals, portal reflections)... well why not? Couldn't we just do what El Scorcho suggested and just have a COG pan the ghost position assigned to the camera to face the same direction the walkplayer's facing?

This is absolutelly great. I love you guys.

If this works... wow.

Well, anything would be possible if something could be done about that flickering. I kinda worked on it a bit more to work like PiP, but it flickers.

Couldn't you hold the previous image for a short time? Or perhaps increase the FPSs of the HOMed camera, so that the switch was less noticable? Perhaps 2 cameras in the same location, and it switches between the 2 back and forth, that way, it never has a chance to switch back to the player's view?

JediKirby

Ok, I've got the beginnings of the portal effect. It requires major refinement of course, but its the basic idea. No flickering really, but there's some odd draw problems around the door frame.

It only works for one side and the teleport isn't set, but doubling the effect and teleporting should be straight forward.

Its just to give you guys an idea...I don't really have a large use for this myself. And I've gotta work on my pathfinding.

HellRaiser if I email will you host?

Ah, just corrected some of the distortion. Forgot to account for the players eyeoffset. It 'wobbles' a little, which, given the fact is a magical portal isn't really that big of a deal.

Still a bit of rendering that shouldn't occur though...its minor but annoying.

Doesn't even appear to be a framerate hit!

If it's small you can attach it to a post.

Let us call the normal view that the player sees the 'player view'. Let us call the other view (like what a camera would see), the 'second view'.

El Scorcho is right about the lack of skewing for a vid screen image, but we might be able to come close enough to make it worth using.

As for making the flicker (as demonstrated by Hell Raiser's gob) go away, we need to have a setup like what El Scorcho described, or a movable 3do that can produce HOM.

Would someone please show some cog or give a test gob that demonstrates a HOMming 3do? If we can make a HOMming 3do, we should be able to make HR's vid screen not flicker anymore.

Oh! El Scorcho, Edward, halucid, and DeTRiTiC-iQ, do you guys have IM accounts?

Jon_Boy2001 at the hotdiddlymail dotcommy :p

I think el scorcho was saying this, but to get rid of the flickering you need to set it up like this...
draw the main view, with hom where the surface is that you want to draw the other area to. Then draw the other area, but with hom that is covering the inverted area.


edit:
It seems to me that pretty much the only case where this will work is when you are able to separate the rendering of the two frames so that they don't overlap on screen. I don't think Hell Raiser's example level can be made to work, because the view from the camera would need to have HOM everywhere but the space that is HOM in the player's view. So, there's a problem when the player can move around, because you can't just use static geometry to accomplish this. El Scorcho's drawing illustrates how you could make it work, but it requires duplicating the current sector and then having the stuff to draw connected through the HOM portal -- problem here is that the view would be restricted to the same view as the player, you are only shifting the view to a new (but the same) sector...end result would be the same as just not using this HOM trick and connecting the sectors to be drawn to the spot where you have the HOM surface anyway (except that you could have the view in the HOM surface be of some area that would otherwise overlap with another sector).
So, problem is in order to make this work you need to be able to match up (in screen space) HOM so that it will be the opposite of the HOM in the player's view...kind of restricts it to just using the player's view in the 2nd camera, because I don't see how you can line things up for any other viewpoint. Now, if you could use 3dos to create HOM, then you could work around this maybe, but I don't see how 3dos could possibly create HOM (at least, not in any general case).
You can create the HOM by just setting geo=0, which is better than just deleting the surface (as in HR's example level), and also allows you to change which surfaces HOM in a cog.

Yeah Sige explained it well. I was created two opposite HOM mirror holes that didn't interfere with one another (basically) and then swapping between them.

You don't really need exact sector matches or anything though. One large sector that encompasses all possible viewpoints is all thats needed. We aren't actually duplicating both sides. We are just trying to create the image in the doorway and nothing else for one side. The original, 'real world' side is just normal with a corrosponding HOM hole to allow the doorway image to remain on the screen.

This just seemed like a logical progression from what Edward explained...or at least how I understood it: Created two alternate dead spots between two cameras and then swapping rapidly between views. Since neither camera has anything to draw on the dead side, they don't interfere with eachother and appear to be a split screen.

Sige also explained the problems with the TV screen, you'd need some sort of amazingly dynamic 3do to block out different parts based on angle...and I think a feature to skew the image as well. Things that we do not have available.

Of course, now that I think about it...just creating overlapped sectors would probably give the same result for the portal...minus the bonus of being able to position the 'other side' wherever you want it to go. I was having some trouble getting translucency to work on the portal, because of course the translucency flag doesn't exactly work on anything besides adjoins....:D

I would really like to see a HOM 3do in action before I get excited about it.

FYI (and I meant to mention this earlier). This has already been attempted several years ago. GBK came up with the idea of using cameras and flickering between the two at a high pulse. He even created a POC (Proof of Concept). I don't know if he still has it, I lost my copy in a recent hard drive crash/reformat. At any rate. The effect is crappy looking as your screen is constantly switching back and forth. I scratched my head for over a month trying to come up with a way to fix it but I finally came to the realization that it simply isn't possible.

Feel free to keep at it though. I still want to see this mysterious HOMing 3do.

Here's a screenshot of a 3do kind of HOMing. That surface is flagged as translucent and set as geo 4. The template sets its thingflags to 0x8. (the HOMing surface off to the right is actual archi HOM)

I've tried it with surfaces set to geo 0, and missing (deleted out of the 3do file) and it just seems to render as transparent (no HOM).

Well, just judging by your screenshot, it doesn't look like the 3do 'HOM' is actually HOM, it looks to me like it is just JK having trouble deciding what order to draw transparent faces in, and so I don't think that would work for this...

That's not exactly like the effect System Override made all those years back, it was much closer to real HOM.

When it was applied to the player character the following would happen:

When the player was stationary he would be practically invisible with just a bit of HOM visible. As the player moved, the HOM effect would become more noticable making the player appear more visible, (any lighting on the player would also cumulatively increase).

On speaking with Det about the HOMing player character he described, I tried this:

Extracting ky.3do and adding the 0x2 flag to each face.
Saved it as kytrans.3do.
Edited the .jkl to change the template of the walkplayer to this new model, and set the 0x8 flag.

Results are below. You can also just about see that that translucent surface on the 3do I posted before IS sort of HOMing.