lighting a monitor screen

bwise1701

I'm trying to light a monitor screen when I make the screen plane emissive and set it's luminance to what throws off a night bright glow it blows out the image on the screen. I have the texture in the diffuse and the emission color channels. Any suggestions? Right now I'm adding one screen that is very low luminance so it doesn't blow out and then putting another just slightly in front with the luminance I want and setting it's cutout opacity to very low .001 but that means I don't get the specular from the light like I want.

Would appreciate any tips. Thanks

 

Doc Acme

This is just a wild guess but try setting the base color for the just the image to 0,0,0, or 1,1,1.  I think in situations like this, the color becomes mulplicative

NorthOf45

We are talking Iray, I presume? The Base colour (Diffuse for 3DL) is what you would see if the display was off, showing only reflected light, so I would set that to dark gray, or whatever the monitor looks like when powered off. There might be a little gloss and texturing, but that's fine tuning for later.

Other products' Iray monitors do things a couple of different ways. They basically involve putting the screen bitmap in the Emission Color and/or the Luminance channels. When used in both, they do multiply, so there is more contrast, but maybe too much (darks are too dark, brights are too bright). Some have a greyscale Cutout Opacity map to tailor the light to keep the blank parts blank without any bleed through from almost-black pixels.

Start with the bitmap in Emission colour (or Luminance), crank the Luminance level to get the right glow, then try setting the Emission base colour (RGB) to something less than pure white. It is true that image light washes out to white as you increase the luminosity, but dimming the emission helps maintain that image. Keep the Temperature about midrange, too low and it gets red, too high goes to bluish white.