Tips for lighting mirror

bueller1998_df4ca4b697

I'm having some issues in my mirror scenes getting the lighting right on the front of the character, particularly the face.

Does anyone have some light setups for this.

The scene I am playing with now is the Dream Closet by Oskarsson, but I have had it with other mirros as well.

http://www.daz3d.com/dream-closet

Anyway, type of light, approximate angle, temperature. lumionosity, and position detail would be helpful.

Thanks in advance!

JD_Mortal

Are you rendering in iray?

Did you load the iray version of the scene? (Light not rendering right)

Does your model have iray skins on? (Faces not lighting right)

Try turning the "Caustic sampler" [ON]... it is off, by default. In the "Optimization" section of the iray rendering settings. (Mirrors not reflecting light right)

Mirrors which demand "light cast reflection", need this to be on. This is not all scenes, so it is not default. It will add a good bit of rendering-time to your scenes, as it has to re-calculate reflections and ray-recasting reflections... (Reflections off the mirror, onto opposing angle surfaces, reflected back at the mirror, and re-reflected back onto other surfaces as stray caustics.)

eric susch

The trick to lighting the front of a character who is looking into a mirror is to ignore the "real" person and light the person in the mirror.  That way you are basically using the mirror to bounce the light back onto the front of the character.

JD_Mortal

I have not tried using both, or just the "architectural sampler", but using both may be better...

Here is a blog about the two IRAY samplers.

http://blog.irayrender.com/post/51722647664/the-architectural-and-caustic-samplers

http://blog.irayrender.com/post/89741414098/caustic-and-architectural-sampler-revisited

(May not see the changes right away... The "plastic" he is talking about is the plastic tubes in front of the LED light clock. You see the "refraction" cast lighting. The LED light is easier to see, but that is the same effect that mirrors kind-of depend-on, which is not rendered without caustics selected.)

Also note the "max path length" should be about 7+ for things like reflections and the layers of eyes in DAZ models. By default, it is infinite.

Here is a demonstration with caustics and glass. 

Note, "mirrors" in DAZ are usually fake surface reflective mirrors. Mirrors in reality are back-reflective, through a thickness of glass. DAZ will NEVER display mirrors like real mirrors in reality, without "tricks". In reality, the surface of glass has a reflection, as well as the back-surface. The thickness of glass offsets the reflection and adds distortion and eats-up light, as well as re-casting through "fiber-optic" trap-light, out the sides. (That mirror/mirror effect, as reflections and glass lenses work by seeing the reflection of a reflection off the inner surfaces, not by bending light half-way through the structure. Which is what stupid school-books teach.)

More info from nVidia... (Caustics part-way down.)

http://www.nvidia-arc.com/products/iray/features.html

mjc1016

JD_Mortal said:

 

Note, "mirrors" in DAZ are usually fake surface reflective mirrors. Mirrors in reality are back-reflective, through a thickness of glass. DAZ will NEVER display mirrors like real mirrors in reality, without "tricks". In reality, the surface of glass has a reflection, as well as the back-surface. The thickness of glass offsets the reflection and adds distortion and eats-up light, as well as re-casting through "fiber-optic" trap-light, out the sides. (That mirror/mirror effect, as reflections and glass lenses work by seeing the reflection of a reflection off the inner surfaces, not by bending light half-way through the structure. Which is what stupid school-books teach.)

You can get a lot closer by making sure that the mirror is actually modelled correctly...that means the glass has thickness and not just a single poly surface.