dynamic shadows eh?!

[Xtasy0]

Originally posted by Apos
We haven't seen anything like that in screenshots or movies: pretty amazing sounding though. The problem, we do see fire in the tech demo, and there aren't any dancing shadows there.

Again: the evidence is REALLY inconsistent. In the exact same scene we see old style "entire-model-pops-into-brightness" AND edges of shadows moving over models realistically. The friendlies in the barney video, for instance, just pop bright when the walk into light patches. But shadows slide over the manipulator in the tenaments/traps section. Confusing as all heck.

i noticed that entire model pops into brightness thing too, and then i looked at the video, and i saw that more often than not the characters have proper shadowing on them that moves as they move, they dont just pop from dark to bright.

heres a few places to look for it.

1) first time you talk to alyx and dr kleiner, there are shadows on alyx as she moves, it happens on her face and neck as well but also her arms and body in general move in/out of shadows smoothly. (also soft shadows on dr kleiner as he moves)

2) the whole first section where you barracade the door is too fast to see any smooth moving shadows, but right after that on the roof, when you first look over the edge before you crouch, you see a combine go into a dark doorway, and as he walks into darkness the shadow moves over him nicely, then in the same sequence later you see a combine walk up the stairs on the left and he comes out of shadows and they look smooth, and then the combine that went in the dark doorway comes back out, getting lit up realisticly as he exits the shadows.

3) right after that during the car explosion headcrab zombie attack, the zombies come from dark alleys and they get lit up smoothly when transitioning from shadow to light.

4) in the barney and allies scene barney has shadowing on his face at the very start. and i just realized, alot of the pops from dark to bright or bright to dark actually have transitions, or partial shadows, like when you move inside the building, one of your allies walks into the second room and if you watch you see most of him get dark except his shoulders, but one more step and his shoulders go dark as well, but its kinda iffy.

5) ung im eating dinner i dont wanna find a fifth example right now.

 

[Apos]

I'm not sure about any of your examples except the combine in the traps sequence (the guy coming up the stairs definately looks like a shadow slides over his body). Again: really conflicting evidence. Pretty definately what looks like dynamic lighting sometimes, and then something that definately ISN'T it.

I would say that maybe the shadow sliding works only with pre-QRADed stuff (i.e. static shadows slide, but no really dynamic in response to moving lightsources, but just stencil shadows used really well, but not working quite right when they "mix"), except that's not quite true either, because the allies in the Barney sequence definately don't work "right": they step into some really different areas of dark and light, but stay the same brightness, or "pop."

 

[Xtasy0]

back to waiting for the videos i spose. heh.

 

[LoneDeranger]

1) first time you talk to alyx and dr kleiner, there are shadows on alyx as she moves, it happens on her face and neck as well but also her arms and body in general move in/out of shadows smoothly. (also soft shadows on dr kleiner as he moves)

Yes! I can see a partial shadow on the doctor when he goes to the computer screen. It's very subtle and more realistic unlike the dark ones in Doom 3. (just keep looking at his head in slow motion.)

2) the whole first section where you barracade the door is too fast to see any smooth moving shadows, but right after that on the roof, when you first look over the edge before you crouch, you see a combine go into a dark doorway, and as he walks into darkness the shadow moves over him nicely, then in the same sequence later you see a combine walk up the stairs on the left and he comes out of shadows and they look smooth, and then the combine that went in the dark doorway comes back out, getting lit up realisticly as he exits the shadows.

Yep, I can see it. Especially clear with the doorway guy cause you can clearly see his foot when the rest of him is dark.


3) right after that during the car explosion headcrab zombie attack, the zombies come from dark alleys and they get lit up smoothly when transitioning from shadow to light.

It's kind of hard to see but I think you're right.

Well, there you go. Finally sombody found concrete proof of dynamic shadows ala Doom 3 in HL2. I now have much more respect for the guys at Valve and their work

Good job Xtasy0

 

[Apos]

We've always known that the human models "self-shadow" (at least that's what I assume is said by Gabe on the Gamespot vids). But the question still is: why sometimes and not all the time?

 

[jhero]

Dont forget the self shadowing best-looking-damn eyes for a game on the planet.

 

[LoneDeranger]

Yeah, in the Barney video the shadows clearly are not working right. I wonder if it has anything to do with lower-quality models for non-important characters. Or possibly some outside scenes are so graphics-intensive that the engine turns the dynamic shadows off automatically to make the game playable.

 

[derby]

In the SDK there is a mention of a Radiosity tool (like there was for HL1). This indicates there is a least some static lighting. My guess is that the world brushes are lit as they were is HL1 (which explains why the shadows form buildings are a slighlty different colour, and a little blurry around the edges (no, its not because the shadows come from further away, as has been suggested as
the shadows are still blurry when columns & walls meet the floor).

Just becasue these shadows are staic doesn't mean that they can't 'move' over model smoothly as seen in the HL2 E3 vids.

 

[Apos]

Right: so this could still leave out new or moving lightsources changing the shadowing or lighting, and shadows blending properly.

I also just remembered that even in the HL1 days you could actually make "fire" flickering lights: maybe they can do the same sort of thing for the shadows in a fire room?

 

[Parasite]

Much of these inconsitencies are probably a result or the scalability engine (Have we decided on a name for that yet? )

At the time of the demo (wich is supposedly 6 months old at the time of E3) the engine probably wasnt entirely optimized to change the proper details at the right time etc...

Remember the engine can go from looking slightly beter than HL1 to even better than is seen in the E3 vids, that leaves alot of room for error, and Im sure they didnt quite have all the kinks worked out yet.

 

[bonanzaguy]

"Much of these inconsitencies are probably a result or the scalability engine (Have we decided on a name for that yet?)"

i believe what you're talking about is LOD

 

[Apos]

I'm not sure that this is something it would make sense to scale.

Also, "popping" doesn't mean that a model suddenly goes bright or dark: it means that the whole model lightens or darkens as it moves from lowlight to brightlight areas. I think this is what is happening with the zombies in the rotor scene. Again: conflicting evidence within the same clip: the combine have sliding shadows, the zombies don't appear too.

 

[Parasite]

Originally posted by bonanzaguy
"Much of these inconsitencies are probably a result or the scalability engine (Have we decided on a name for that yet?)"

i believe what you're talking about is LOD

No no...not level of detail, that refers to geometry and mip models. I mean ability to scale back or scale up engine features to take advantage of the technology on the fly...This scalability engine also helps maintain FPS by scaling back the texh features not currently on screen.

And Apos, I understand what your saying, but its possible.
Look at the inconsitencies in this pic for instance...

Shadows, including the light cast by the guns are all different.

It would make sense to scale something like shadows and lights scince they are some of the more processor intensive elements the engine has to deal with and there is no way to create an LOD for lighting or shadows, exept to use a different process to create them. IE dynamic shadow cast from a charecter in the forground, and a stencil shadow or light map cast from a charecter in the distance, where the detail is less discernable.

Its just speculation, but it seems possible to me. :shrugs:

 

[Apos]

Right: also check out the gun placements in the bug/jail video. when they die, they light up the general area, but the light doesn't cast shadows anywhere: it just brightens the local area. It looks nice: you can see specularity on the power cord on the wall for example... but it isn't dynamic shadowing.

 

[Parasite]

Well, they are "dynamic" in that sense...maybe thats what Gabe meant. I was just pointing out that many of those little discrepancies could just be from using an unoptimized version of the scalability feature.

You are right though, HL shadows are definatly not dynamic in the same sense that Doom3 shadows are, but D3 makes a significant trade off to achieve those incredible shadows...Both engines puch a similar amount of polygons, both with significant detail, atmosphere and realism. They are both pretty even on these terms. HL is using less resources to create uber scary realistic shadows and in turn allows for thigs d3 had to sacrafice, like AI, Physics, Materials, Outdoors, Realistic refraction (not sure about that one :/) And D3 has no real low end currently, its pretty much set to run on current technology.

HL will own but it will never achieve that feeling D3 will give when some malformed creature slowly emerges from a corner, shadows slowly revealing it...or barely discernable silouettes scuttering across a wall in the darkness...Holy crap I cant wait for either one of the se games!!!

 

[Apos]

Of course, we don't really know what D3 had to trade off. But at least HL2 seems, apparently, at least sometimes capable of the same sequence: shadow sliding across a huge new creature as it steps into the light.

 

[Apos]

Oh, i just realized what that thing in the bottom foreground of that screenshot probably is: a folding chair! Duh on me...

 

[jhero]

Thats one strange chair...

 

[Apos]

No, think about it. It's the top of the chair viewed slightly from the back: there's the rim of the chair, and then you can see where one leg is coming off the far right side. Get yourself a folder chair, and then look at just the top part from the right angle: it totally works.

 

[jhero]

OH i see it now, thnx.

 

[Apos]

I was confused for the longest time cus I thought that the gun on the ground was part of it: it looked like some sort of demented steering wheel, as if gordon was driving around in a bumper car watching the battle go on.

 

[jhero]

LOL, it sorta did look like that didnt it?

 

[derby]

Just noticed, in that screenshot, the combine guy's gun doesn't cast a shadow at all, look at the shadow of his hands. Sorry, if this has already been noted.

 

[LoneDeranger]

Originally posted by Apos
I was confused for the longest time cus I thought that the gun on the ground was part of it: it looked like some sort of demented steering wheel, as if gordon was driving around in a bumper car watching the battle go on.

LOL .. I'm still not exactly sure what that thing is .. it seems too big for a chair. Might be some sort of a table.

 

[Apos]

it's nto too big when you consider that it's right up next to you.

Yes, it's been noted.

 

[Pr()ZaC]

I guess you have to wait for an official clip from the game.
Then, mail Gabe to ask tech questions we can answer just by suppositions.

 

[Parasite]

Its a folding chair Lookin at one right now...its like the kind wrestlers hit each other with.