Chromatic Aberration Material on a mesh ( not post process )

[frozenfire2]

Is this possible??

I'm aware that the current chromatic abberation method is to take scene texture, distort the UV of the R and B and then append it back.

any idea how i could do this on a specific Mesh? can't seem to think of a way to do it. It seems that I'm allowed to distort the object
one time through world position offset. If i could draw the object multiple times perhaps I could draw each of the RGB channel individually and
distort them through world position offset . Any idea how this could happen with only material ?

[frozenfire2]

bumpp.. anybody????

[frozenfire2]

one final bump...

anyone still?

[Solid Snake]

Is this effect similar to what happens in UT3's Redeemer camera?

http://www.youtube.com/watch?v=stE0WogisEw

[DGlow]

Alright first thing I tried was doing the same techniques as a post process version but just on the diffuse texture. Offset and Append


But I don't think that's exactly what you wanted so I started messing with the world position offset



Failed a few times, discovered some nodes that are not even on UDN



Started to get pixel separation but nothing that really worked.
Then I tried a new direction with making 3 materials, each using a single channel from the diffuse and multiplied with a constant3 using the same base color. duplicating the mesh and offsetting it manually (or with world position offset)


Then I found this material blend mode called alpha composite or something which i turned on for the model that's using the standard RGB and got this


And then UDK Crashed before I got my next test done. I hope this helps you.

[frozenfire2]

so much bumping i forgot to check this thread.

@solidsnake : yes I believe so; but redeemer's one is post process I believe, I need it to be on ONE mesh not the whole screen

@DGlow : looks like you made some interesting discovery there. However I don't get some parts you are talking about, how would you make THREE material for a single surface. you can't apply 3 material ID to one mesh on the same surface can you? Only workaround I see is rendering the mesh three times. Can you explain your methodology for the final shot again? re-phrase?

[Henrik]

He made 3 seperate materials and applied them to 3 versions of the same mesh, each in charge of one channel (R, G and B). Kind of clever, but certainly resource intensive for anything larger scale...

[frozenfire2]

yeah that's the closest workaround I can think off as well. putting 3 piece of mesh component in one object. but this doesn't seems quite right as shader language by itself should be able to be given instruction to render multiple times or at least render once but displace/offset the channels multiple times on screenspace.

[Dralex789]

yeah that's the closest workaround I can think off as well. putting 3 piece of mesh component in one object. but this doesn't seems quite right as shader language by itself should be able to be given instruction to render multiple times or at least render once but displace/offset the channels multiple times on screenspace.

Some interesting information on this thread. Since you cant access render passes I wouldn't really know what to suggest. If you could that would change everything (chroma key) but without it I wouldn't know. The 3 mesh version is probably going to be your best bet, but you mind as well make it all one object and make it transluscent (but that is very spendy)

[frozenfire2]

that's true..... on a sidenote I remember ambershee mention about the early UDK being able to access to the .USF and stuff. Not sure if it's still possible or it'll help. Would be fun to see what can be done. For now I take it as it cannot be done without having 3 mesh.