How to learn background lighting .. Iray vs. 3ddelight.. any good tutorial videos?

heisdave

Hi  I am experimenging  with lighting, Im trying to light my background and work with areas of shadows using iray. 

I add a spotlight to a dark room and point it at the wall, what I want is a circular area of light and detail, and outside of the circle should be darkness and shadow, and when I render with 3d delight this is the exact result.

But not with iray, with Iray the wall is uniformly lit across the whole surface, no shadows. I tried to turn the spotlight's  intensity way down but it doesnt seem to fix the issue.

So I want to take a step back and try to learn iray lighting from step 1, are there any good youtube videos or tutorials anywhere? Thanks

 

Mazh

There's a setting in the Iray Environment render settings which controls the lighting in your scene,

make sure it's set to "Scene Only", else there are also other lights in your scene.

http://docs.daz3d.com/doku.php/public/software/dazstudio/4/referenceguide/interface/panes/render_settings/engine/nvidia_iray/environment/start

 

Havos

You can do it in IRay, but you need to set to Scene Only, as Mazh suggests, and also ensure the camera head lamp is set to off. For the spot light, set a smaller Spread Angle (I used 25), bump up the Lumens to some big number, and change the Beam Exponent to 1. The circle is unlikely to be as sharp as in 3d delight, but will more realistically show the behaviour of a bright spot light. Below is what I got shining the light on a white painted wall, and a brick wall.