Reflection On Pure White?

[peterparker242]

Hi,

i postet a problem a couple of days ago. Maybe i discribed it a bit complicateted. What i need to do is to get an object reflected on a pure white plane. But somehow the white color on the plane seems to suck up (outshine) all the reflection. I tried Backgroundshader, layerd etc. but couldnt get a reflection on a pure white plane. Works with darker colors but not with white. Would be great if there is a setup for this in Maya, without going to compositing, cause its an animation and the reflections needs to fade into white color.

Can someone please give me a hint how to solve this, thanks.

[joojaa]

yes reflection is additive. So if you add something to 1 1 1 then ist still going to be 1 1 1 on screen becase it oviously your monitor cant show colors brighter thatn white.

However its totaly possible to get the reflectipon on teh white plane, ist jsut going to knock out the clorors thats all... It will not look like a reflection to human eyes offcourse. Its not hard jsut use a extra node that just takes reflection and leayer iyt ovvertr the backgriound shader.

Im just not sure if you realize this.

[peterparker242]

Hi,

thank You for your fast reply. U r right with "Im just not sure if you realize this.".

Cant get the reflection to show up. Camera Enviroment set to white. Used a phong - reflection 1, transparent 1 - and Background shader, combined them as layerd shader. Picture renders pure white.

Please help me a little further. Thanks, Peter.

[joojaa]

yes but how is it you need the reflection to react? Imena if you just puch ist trou will look very ynnatural indeed. So whatkind of layaring do you want. multiply, screen, overlay, juts pure reflection and white where is no reflection, mix of the above or what. (difference, exclsion, hue color saturation are also possible.)

I mean 1 1 1 + 0.5 0 0.8 is still 1 1 1 to the menitor since it can show whiter than white And no if your cilent asks for more whiter then pure whitre your only way aout is to yturn the brightenss and contrast of teh display device up! Its rather like trying to print whiter paper, wich unlike this is not physicaly impossible. (and yes its possible by the way)

Its very unusual to se stuff in relaworld that makes areas with reflections darker than the underlying tone (that is there are NO such things), wich would make it wierd to look at indeed.

[peterparker242]

Thank You for taking your time.

Please have a look one more time, heres an example of what i am trying to achieve.

http://www.archkite.de/example/

I cant be this hard, but i dont know how.

Thx, Peter.

[failure]

What is reflected is always the light. You cannot reflect darkness. But you could make some reflection darker than other. So if you want to create an illussion of dark reflections you should make all reflections except the dark ones - very bright. In other words your reflected enveronment should be white - not your reflecting surface.

As far as fading is concerned, it really has no equivalent in optical phenomena but you can fake it in a number of ways using texture masks.

Picture below was made entirely with maya. Floor plane is actually black reflective blinn but the camera environmet is white. Fading is achived by masking that material with white-ambient lambert using layered shader.

400) {this.resized=true; this.width=400; this.alt='Click here to open new window';}" onmouseover="if(this.resized) this.style.cursor='hand';" onclick="if(this.resized) {window.open('http://16x16.org/3d/files/reflection_white.jpg');}" />

Example scene

[joojaa]

Well there no real good way of doing the fade without compositing, custom raytrace shaders or using duplicate geometry.

So yoru looking to push the reflection with a standard alpha over. no prob.

there are severa ways to approach this. the fact that you use a colord background plate make sit a bit harder to workout with the easiest approach but ist doable:

this si what id do is you take the outcolor usebg shadhader connect it to a +-avarage athen connect the matte opacity to the next slot of +-avg and set mdoe to subtract (now this is a trick that spcificaly works for white color ifd the color is NOT white you need to work on the matte opacity color a abit and tint it to the bg color)

Now for the faded reflect that needs a duplicate object and a duplicate material that fades into the sky

That said theres many wqys to filet this fish. And in general if i wat easily doable in comp THEN DO IT IN COMP because this has a added benefit for you. Theres no idea in ofrcing a singlepass render fi you can do is painelssy in comp. Hell most of us ework much to SPLIT things into comps just because of teh added flexcibility at cruch time you should to.

[failure]

Yes, comp is alway preffereble to pushing it all in 3d. But exact approach depends a lot on what actually happens in a shot.

Beginners often look for too generalised solutions. Smart way is to first fully define your shots and then seek most inteligent/flexible ways of executimg them. For a slight camera dolly on stationaty objects an animated 2d mask would suffice. If you have a long, complex camera flythru with objects bouncing around, writing the custom shader is reasonable option etc...

[peterparker242]

Thank You Joojaa and failure for taking your time on explaining this reflectivity issue. Got my scene to work! THX!