Aliens should have reflective eyes

Pistachio · April 2012

The other day while driving at night a raccoon(I think) ran across the road a hundred feet or so in front of my truck. Its eyes reflecting the light of my headlights was the only thing that gave it away.

It got me thinking.

Why couldn't alien eyes reflect marine flashlights?

To keep it balanced, it would be best if alien eyes only reflected flashlights while the alien was using alternate vision. The effect would make sense that way as well, because presumably the aliens eyes change when seeing in the dark. Anyway. This adds a subtle dynamic to stalking marines in pitch black, not only with positioning to avoid giving oneself away, but with strategic use of the alien "night vision", so as not to chance being seen. As in real life, I would expect an area outside the cone of the marine flashlights(to the sides, and towards the front after the light fades) to cause the reflection.

Something like this would help give stronger purpose to both vision modes, and keep players from over using the alien "night vision".

In addition to the gameplay elements, it would make for some striking visuals. Imagine pausing in front of the doorway to a darkened room, and switching on your flashlight only to see five pairs of eyes staring back at you. Eerie.

Thoughts?

paradoxum · April 2012

good idea

rantology · April 2012

but that would make the marine flashlight useful...

sorry I couldn't resist :>

bcarrot · April 2012

my "bioluminescence > alien night vision and back up lights" topic would work really well with this because there wouldn't be nearly as much light in the alien areas so they would have to use the flashlight more. That mixed with your reflective eyes would be awesome.

Corpsey · April 2012

The effect is called 'chatoyance' or 'chatoyancy' and it's actually difficult to replicate it in 3D.. :\

If some devs are interested I have some values that fit into a blinn that can give this effect, but I'm not a texture artist so actually creating the eye texture maps to demonstrate it perfectly is not going to happen quickly.... I'll work towards getting texture maps but if someone has a more streamlined texturing pipeline it would be faster. PM me for the blinn values. (Not even sure which material values spark can handle currently.. I know there's basic specular mapping but it requires eccentricity and falloff).

Floodinator · April 2012

Alien Eyes already glow if they are in Alien Vision.

Corpsey · April 2012

Glowing is different :P glowing just uses bloom.. the effect he's thinking of produces more bloom to things that are parallel to to object and with a light source directly bouncing photons towards the subject..

I've actually been studying and trying to recreate this properly for a couple years.. because my birthstone is Opal. It's not as straightforward as you'd think to create something like that in 3D programs :P

Another thing that's difficult in 3d is quartz. There are ways, sure, to get refractive qualities.. but to actually get a 3d effect, and especially transferring into games or low-res, some/most of the effect is lost. That's not to say it's impossible but the refractions and glossy values needed take more time to compute..

Though for the cats eye effect it's different because it's one plane and there's no transparency. Again, I have values for a blinn that can reproduce this effect.. I will make texture maps of cats eye texture for a demo soon but I'm not the greatest texture artist >.>

<img src="http://img18.imageshack.us/img18/6467/catseyedemoch.png" border="0" class="linked-image" />

Okay so..

Fig.1 Has a light directly "above" it, and you can see that it is quite bright but still has much detail with the plane at an angle that the light isn't reflecting directly back.
Fig.2 Has a light directly above it (same as Fig.1), and is angled so that the light is hitting it and reflecting directly back, this effect occurs due to a set blinn specular falloff
Fig.3 Has the same light from Fig1 & 2, but move off to the right a bit. You can see that it is no longer intense, but still emits diffuse.
Fig.4 Of course though, natural selection eyes glow naturally so this is using the same light off to the side as Fig.3, but with some small added glow just for the demonstration.. It was done somewhat sloppily because I was too lazy to add the ambient as a full map (which is why the pupil has color)
Fig.5 This uses the same light as Fig.2 and the same glow as Fig.4.. you can see that if there's no/less light on the surface you only see the diffuse and ambient + glow maps, but with light directly shined onto it and reflecting back into the cam it's much more intensely lit.. even the outer rim is lit by the glow.

Also... if I wasn't lazy I could have put a refractive or even just extra reflective layer of polys so you could see the actual light source.. it's not reflecting a plane, it's reflecting a point light to create the effect (so there would be a point light reflecting off the extra layer if I chose to put one). I could upload an image of that if anyone really wanted :P

Edit2: <a href="http://img214.imageshack.us/img214/9272/catseyedemoch2.png" target="_blank">Added a quick reflective bubble</a>.. uh..it's still very bight in the angled one but mostly because the light is very close above it and somewhat because the glow applied in the last one is still on, but if you look closely you can see that there is almost white hue in the direct on one that isn't present in the angled one (Not to mention, I probably have multiple reflections enabled so there is a double-intensity thing going on because I forgot to make the bubble single-sided). Fig 1 and 2 use that light off to the side, so there's only diffuse (and ambient for glow). The reflective bubble uses the Phong shader that I heard one of the devs say is used in spark in one of the UW youtube vids. :\ anyways.... again the plane is using blinn node attributes so I don't think these can exist in spark.

Pistachio · April 2012

That's awesome, Corpsey. Thanks for putting those up.

It's essentially exactly what I was envisioning for the effect. The most important aspect being the varied intensity based on the viewing angle. Alien players would have to be more thoughtful of their positioning, with that kind of dynamic, when preparing for an ambush on marines.

I gather you've been working on these kinds of effects for some time. Out of curiosity, how long?

______

I don't know how it would work exactly, but would it be realistic to create the iris as the facet of the eye that reflects more strongly than any other part?

Like this -

<img src="http://www.fotothing.com/photos/1d9/1d91d341818ed993bee7b899211862c0_ca7.jpg" border="0" class="linked-image" />

Also this is kind of what I imagine a marine might see in a dark room -

<img src="http://farm3.staticflickr.com/2225/1506289970_826da27308_n.jpg" border="0" class="linked-image" />

Corpsey · April 2012

I can actually get that exact effect.. but I'm not sure it can be transferred into the game and I'm not sure many people would like it if it even were :P

Does anyone know if spark supports blinn shader?

I've been working on it for an embarrassingly long time, since early 2009.. I've always been fascinated by dichroic, polychromatic, crystalline, minerals & materials and the like.. and I asked someone how to recreate Opal in a 3d program and their answer was basically "fake it" and so I've come up with some ways to do that through procedurals but I tried not to rely so much on them because procedural textures do not like videogames as is... so I've been just experimenting with any and all values possible, and I eventually got into using mental ray in maya so much that I can produce probably any effect really.... except liquids.. sadly I still need someone to show me how to work realflow - I've just never got around to it. Also Opal is still a very tricky stone to reproduce.. the bottom line is that it will have to take maps with values to look right, or faked like crazy - but I like trying to get things to gleam as naturally as possible in Maya :P

Aliens should have reflective eyes

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