I feel like using the lion picture as a reference texture isnāt the best idea because really in a game I donāt think anyone would try to convey so much detail in a parallax map. Probably it would be better to model a low poly lion head and use an ordinary normal map and just hang it to the wall. So I think the lion head is great for the intentions that the researchers had when writing their papers but not so much as a practical āfield testā of typical or recommended usage for the feature.
I modded Crysis for a while and even Crytekās geniusesā version of parallax occlusion mapping had texture swim if you tried to use it to convey too much detail. I mean if you make a wall texture in CryEngine 2, then you get next to the wall and look up at it at a sharp angle youād get this weird warp effect that made the texture look like it had a miniature warp hole in it that leads you off into oblivion. And this is wall art made by modders who really knew what they were doing so it was a technical thing as opposed to human error. ā> Video Testimony by Crysis Modder: http://www.youtube.com/watch?v=0bBEgZ03HM0&feature=channel_page
This is the reason why Crytek themselves never used parallax on their walls even though they could have. Performance/aestic wise it was much easier to just add the geometry.
That said they used parallax for the terrain in Crysis and because of the fact that the ground plane stays relatively contrained on itās axis in reference to the player viewer angle the texture swim/oblivion void artifacts are kept to a minimal almost to the point where the player wouldnāt ever notice unless they just really are out to find them. Also for terrain textures you can have a ground plane and pebbles and things that are nice and spaced out so that the height displacement effect really shines through moreso than in the lion texture where the bricks are really packed too tightly together for the full effect to shine through very well in my opinion - notice how this more game friendly example of parallax has the displacment detail spaced out better --> this type of image in my opinion is better to look to as a reference texture. Better Spaced Out Texture than the LionImage (more common usage of parallax for realtime in my opinion): http://www.youtube.com/watch?v=UeF-kCr_vyo
XNA parallax example: http://www.youtube.com/watch?v=GwOfIsSMQJM&feature=related
Here is example of the only places where crytek saw fit to use Parallax in the whole entire game that Iām aware of
With everything else in mind it makes a wonderful effect for terrain and you can see that the pebbles look more like the examples in the youtube videos I linked to than they look like a bunch of tightly packed bricks. Not that parallax couldnāt be used in that way itās just Iām not sure if itās even the smartest way to approach texturing a real time scene to begin with. But donāt just take my word for it :ba:
So like I said with the advanages/disadvanges of using parallax it probably isnāt best suited for trying to convey a complex world on simple geometry in the same sense as everyday normal mapping but in some cases it can be a godsend. Like on the terrain. Iām sure in other areas too like on really big craggly surfaces, as opposed to that lionhead texture with all the close detail jampacked together the way it is.
To me Iām still a little bit confused by the whole thing. Even very good artists get the naming of all these parallax techiques mixed up and they mean relief mapping but they call it parallax occlusion or they mean steep parallax but they call it parallax displacement and Iām not even sure if there is a difference between every single one of the names Iām no expert. But thatās my little my little input.
That said I personally wouldnāt have more than one-two examples of Parallax of anysort visible in a real time scene at any particular time cuz to use it to the full effect itās still a bit overly expensive. So for me I would use it for terrain, as is the case in Crysis, as well as for the impact of maybe rustic wooden objects, just for āwowā effect. Not because it should replace everyday normal maps.
And as you can see in the CryEngine pics it really can make a nice impact on a scene in my opinion, even though some people dontā like Cryteksās rocks I do! I think itās neat.
That said I think your demo is great itās just hard to really see it with that texture and unfortunately I havenāt had time to make a parallax image specifically for the new blender scripts so far.