Stained Glass

[John Ferris]

Interior church rendering with some stained glass windows. The stained glass looks different when all the layers of the model are turned on vs when just the stained glass and window layers are on. Can't figure out why. Tried freezing the interior lights but no effect. See attached images. Would like to send the file but it's too large - options to send or post? Thanks - John

[Roy Hirshkowitz]

Normal exposure behavior.  The windows are very much brighter than the surrounding wall.  Without the wall, they're darker than the pure sky.  You may need to fiddle with the colors in the bitmap some to get what you need.  Always test with the wall present but you may want to try some different sun angles.

[John Ferris]

The stained glass windows are modeled, not images. Just fiddle with the individual glazing materials? Any other things I can do with the materials (attached)? I'll try changing the sun angle as well. Thanks - John

[Roy Hirshkowitz]

I would probably use an IOR of 1.55 or so.  My inclination would also be to use a transparency of 1.0 and control the amount of transmitted light by darkening or lightening the colors.  The reflective finish you should use depends largely on how the material is actually produced.  If the surface is smooth like normal glass (even if it has a macro-texture-- like the ripples)-- the reflections should be sharp.  If, on the other hand, this surface is rough, than both the reflected and transmitted light should be blurry.  "Allow Surface Roughness" on the transparency page is a decent way to do this.

If the windows are modeled using a single layer, make sure they're tagged as "Thin" in object properties.  That will increase the effect of darkening the colors.

Finally, there are limits to how well the tone mapping can reproduce both extremes of brights and darks that you might encounter in a sanctuary interior.  Trying to photograph the interior of a cathedral, for example, is a very difficult task.  You may need to cheat a little to prevent the windows from being overexposed.

 

[John Ferris]

Thanks Roy...Good, prompt, accurate (no pun intended) information. Will incorporate.

John