New : fake enviro reflexion refraction shader material at low cost !

[ben]

Well, it's late and I can't sleep...
so I uploaded a video of a test for a new enviro reflexion refraction
shader I was working on.
In fact a modified bitmapMaterial with two new properties
and one new line of code in the abstractrendersession, so that you
just have to prebake your bitmapdata in photoshop and set:
yourBitmapMaterial.refract = true;

The starting point for a lot more experiment I think...

Fake because it's only a bitmapmaterial (you can do whatever you want
with it (composite, etc...), and that's a good point
and it's pretty low cost in perf...

I'll publish the code soon if you guys think that it deserves to be
shared, so let's comment !!
I know some will say that it is not really (in a physical way) what it
seems (real reflexion, etc...), but it looks like, and that's what I
wanted.

PS: sorry for the bug in the video, but I have to change my capture
tool...

here it is :
loud quicktime version (sorry...it's late for me):
http://www.agence-anonyme.com/lab/nouse/enviroPrebacked.mov
on vimeo (in about 1 hour from now):
http://www.vimeo.com/5515775

[Matt N. M.]

Looks very cool. I can't really tell what's going on or whether the
result is accurate. It seems a little quirky. Can you do this on a
cube within a color coded environment map? or a map of terrain?

[ben]

"Quirky", here we are !
yes it might be considerd as a way to render some kind of reflexion/
metal/crystal material at low perf cost.
I created it because of a project with a lot of mesh and texture and I
had to find tricks to display that kind of texture without perf loss.

Anyone would see something glossy and reflective ( thanks to our brain
habits) by looking at it... that's what I wanted
it's just an illusion !
;-)

[Li]

Looks cool indeed.

Could you comment on how it works a bit?

[ben]

Glad you like it !
the fact is that I don't have the code under the eye,
but in fact in the final drawTriangle method of the session, you make
a swith on the matrix used to solves the bitmap :

like :
if(refract)m.scale(a2,c2);
if(refract)m.scale(.5,.5);

you pass the "refract" boolean value by creating a bitmap new property
with getter/setter and pass it when the bitmapMaterial calls for the
session.
so all you have to do is add a line in the abstractrendersession
and set
your bitmapMaterial :
yourBitMapMaterial.refract = true;
(or pass it in the init object)

you can imagine nice effect in a composite material.
I'm working on other effects and some more accurate method.

I'll post the code tonight.

[Li]

yeah, but beyond the usage, whats going on?

[ben]

well as I told you, in the abstractRendersession :
in the bitmapMaterial class you have 1 more properties
you set refract (or whatever is the name of your property) to true

then to the line (don't remember where):
session.renderTriangleBitmap(bitmap, map, v0, v1, v2, smooth:Boolean,
repeat, layerGraphics,refract):void

renderTriangleBitmap(bitmap:BitmapData, map:Matrix, v0:ScreenVertex,
v1:ScreenVertex, v2:ScreenVertex, smooth:Boolean, repeat:Boolean,
layerGraphics:Graphics = null,refract:Boolean = false):void
{
.....
first calc the matrix(m), from map and vertices
then :
if(refract==true)m.scale(.5,.5);///or some other way , more accurate
I'm working on.
...
draw the graphics in the view
}

that's all for basic !

[Li]

Ah, wonderful. So you're just messing up the UV matrix a bit. Cool =)

[ben]

Yes that's not a good idea for simple objects with low count of faces,
but for complex objects it makes the trick...very well I think...

I mean in a user point of view, enjoying the whole thing, not for the
disturbed mind of some dev ;-))

but it's a first try, I'll be searching for more result (scale more
depending on distance,etc...) and other effect not too compete with
the existing material, but to add an alternative...