shadow in shader which is 100% reflective

[j]

Is it possible without compositing or reflection of less than 100%
to have a shadow in for example shader that simulates water?

[Heavily Tessellated]

There must be a language barrier here, I know all those words but reading them the way you put them together I haven't the slightest idea what you mean. :confused:

Is it possible... without compositing, or reflection of less than 100%... to have a shadow? (in, for example, a shader that simulates water.)

?

Anything can have a shadow. You can make a totally transparent material, but if the material(s) that the shadow falls on doesn't have TraShad turned on, the object in question will cast a nice solid black non-realistic shadow there.

I'm pretty sure this isn't what you're asking. :D Could you explain in more detail?

[j]

Hi HT
I cannot get shadows on a plane object which resembles water.
Shader of the plane object has raymirror on and its setting with slider is 1. When i set up lights so that a soft shadow or raytraced shadow should be cast on to the water/plane object I do not get in render any shadows to the water/plane object.
Trying to get shadows of a bridge casted to water in this scene:
http://blenderartists.org/forum/showthread.php?t=69652

[mpan3]

Well, technically you can't have anything perfectly reflective and have shadow fall on it at the same time. Anything that is 100% reflective means it does not show any surface color/shading of its own, but instead, all the color on the object is a result of lights falling onto it from some other place. The water example you posted has shadow because the water is NOT PERFECTLY reflective, it has a fresnel factor which makes it less reflective as the angle of the surface is more perpendicular to the viewer.

I hope my explaination was concise enough, if not, ask yourself this question? Can you have an object be 100% reflective red at the same time? No...

Seldom things are 100% reflective in the real world, except for maybe mirrors (or things like mercury etc) which can be seen as nearly perfectly reflective. Anything else all show its own color to a certain extent.

[Heavily Tessellated]

Ah, the GWB. Nice job! And you can Google for about 1,000,000 photos of it from every angle if you get stuck.

Yep, you can't have a shadow cause a 100% mirror is reflecting the shadow too. Technically that's not how it would work, because a shadow can fall on anything, even matte black... that's not the point, though. :D In Blender, no, you can't have a shadow show up on a 100% reflective surface. It's not you, it's the way things are.

For daytime river water I wouldn't go over 40-50%, for night time you can crank it up a bit because you can't see the water texture but still wouldn't go over say 70-75%...

If you want to try messing around with water "depth" you can also make the top reflective layer translucent and give it a proper IOR for water, and make the blue/green clouds on another plane a bit below it... if you have RayTrans on and alpha set low, it will attenuate the light hitting the secondary layer, play with Filter to get the strength you like... it fakes deeper water without too much overhead (especially for a one-frame still)

Don't forget that rivers have current and whorls and ripples and stuff, you can make a bumpmap with Wood and turbulence and make the reflection pick that up... oooh yea. :)

BTW, the uprights are illuminated...

http://www.columbia.edu/~nad7/neighborhood/GWB.html (http://www.columbia.edu/%7Enad7/neighborhood/GWB.html)

[j]

Thanks mpan3 and HT

The render that has shadows in it was post processed from two renders.
Black and white render with only white and black as the shadows...gimp...alphaimage...

Thanks for c+ HT, I am going to see about setting a yafray render to be processed.