Glowing computer screen with Iray

bwise1701

Does anyone have any tips on settings to get a glowing computer screen that doesn't blow out the image. I did a quick search of the forum but didn't find anything pertinent.

Thanks

mjc1016

Can you post your current settings?  It's easier to see what's already there and adjust.

CrissieB

Is the computer screen in-frame with your camera angle, or is it illuminating something else (like the face of a character)?

If the screen is in-frame, and if you've made it an Iray emissive, you'll probably want a very low Luminosity setting, maybe 100 lumens, depending on the rest of your scene's lighting ... just enough that the screen looks like a light source.

If the screen is illuminating something else, you'll need a higher Luminosity setting ... enough to cast light that looks like it's from a computer screen.

If you're doing both -- the screen is in-frame, and you also want it to illuminate something else -- you'll need both a Practical emissive (the screen you see) and an Scene Light emissive (one you don't see, but that illuminates the scene as if​ it came from the computer screen). To do that:

(1) Set your visible computer screen as the Practical emissive, with very low Luminisoty: again, maybe 100 lumens, depending on the rest of your scene's lighting ... just enough that the screen looks like a light source.

(2) To make your Scene Light emissive, create a primitive plane the same dimensions as the computer screen. Position it 1mm in front of the computer screen, and set its Luminosity to a level so its illumination looks right on the other objects. ​Set it to the same Emission Temperature as your Practical emissive, then ​turn Two-Sided Light off (you may need to flip the plane's direction to be sure it's pointed outward) and set its Cutout Opacity​ to 0.0001​, so it will be invisible. Then parent it to the computer screen.

Now you'll have a computer screen that appears to be a light source and illuminate surrounding objects, without glare or washout.

I use this Practical/Scene Light trick anytime I have a light source (lamp, computer screen, etc.) in-frame. In fact, when I model a light fixture, I create two emissives: a dim Practical and a brighter, invisible Scene Light with the same color temperature.

You can see an example with the ceiling fixture below. The Practical light is a tube that runs around inside the frosted glass shell, just bright enough to light the inside of the shell. (It's one tube, but it looks like several because of the brackets.) The Scene Light is an insivible shell just outside the frosted glass shell ... and it's bright enough to illuminate the room. Indeed that fixture is the only light source in this scene. It looks as if the light you can see (the tube) is lighting the scene, but the real scene illumination is that invisible shell. If the visible source were bright enough to light the scene, I'd have awful glare from the silk wallpaper.

I hope this helps,

Crissie

MarcCCTx

Here is one with http://www.daz3d.com/real-lights-for-daz-studio-iray​. Applied the Monitor Screen setting to the screen and then taking the original diffuse map from the screen and putting it in the emmission channel andong with some green (it's supposed to be an old mono monitor. I lowered the Luminence to 900 to keep it from being too bright.