Iray lights are confusing to me....

Blastedlabs

I finally sort of had a handle on 3dDelight's lights. Well, Iray is amazing for obvious reasons.  However, the lights are very confusing to me.  For example, I was doing a spaceship around a planet.  The planet was lit by one of the presets and looked fine, but the spaceship was in the dark.  So I tried adding a light near the spaceship, and suddenly the planet became pitch black...

http://www.daz3d.com/blue-planet-orbital-view

Khory

Is the product set up for Iray? And what sort of light did you add near the spaceship?

kaotkbliss

I thought I had a handle on Iray lights as well, but then I started working with interiors...

you can have a single 100 watt light with a lampshade in a room and it gets lit up just fine in the real world.

Yet with Iray, which is supposed to mimic real work light, 4 100 watt lights barely makes anything visible.

I've got 1 scene that has 8 10 million lumen lights plus countless emissive surfaces and the iso set to 45000 and it's still dim.

 

 

For your space scene, how are you setting it up? are you using the sun node? are you using a plane with a space surface applied to it? I used to set up my scenes with a plane primitive for the background and would turn shadows off in 3delight. But you can't do that in Iray. The plane will always cast a shadow and depending on where the sun is, could cast a shadow over your entire scene.

Steven-V

Something's wrong if you are using that many lumen and that much ISO. I have had 2 plane emissives with 12,000 lumen each (roughly the right amount for a bank of real-world fluorescent lights, like in an office bulidng or hospital) and under f/2.8 with ISO around 800 it looked fine.  If you keep f/8, you'd need ISO around 1600... but still. 450000 doesn't make any sense with 10 milllion lumen lights. Something does not sound right here.

fred9803

I think Iray might not be well suited to a spaceship type of scene considering that in space you don't much other than stark direct light and virtually no anbient lighting. 3dDelight could be best for these sort of scenes.

Novica

Blastedlabs said:

I finally sort of had a handle on 3dDelight's lights. Well, Iray is amazing for obvious reasons.  However, the lights are very confusing to me.  For example, I was doing a spaceship around a planet.  The planet was lit by one of the presets and looked fine, but the spaceship was in the dark.  So I tried adding a light near the spaceship, and suddenly the planet became pitch black...

http://www.daz3d.com/blue-planet-orbital-view

Well, I have that product. Can you tell me what you're doing, what spaceship, it's coordinates, and your settings in Tone Mapping and Environment? What light(s) are you using? I'll play with it and show you how to lighten up whatever you're doing. You are aware that spotlights are affected by both Intensity and lumens in Parameters? If you're only doing lumens, try increasing your Intensity. 

Novica

Blastedlabs- are you aware that you can use your viewport as the aiming tool for say, a spotlight? If you are in Perspective View for example, create a camera (Create>Camera, up at the upper left) and name it (let's go with Camera 1) and in the popup, choose to "copy Perspective View" (something like that, may not be the exact wording, I am rendering and can't stop to check right now) then you will have a camera that is identical to the Perspective View. Go in the upper right of the viewport and click on Perspective View, in the dropdown select Camera 1. Now you are in Camera 1 view in the viewport.

Pretend you are the spotlight, shining on the scene. Move your view (Camera 1) to however you want the light to shine on the spaceship. I would suggest always starting with one that strikes most of the prop, aka, if you have a side view of the spaceship, then try a view that shows the entire side. Now go up to Create>Spotlight, and for the popup, select Camera 1. You have now created a spotlight (which I would name Spot Side, so I knew it was hitting all the side of the spaceship) exactly as the view you had in Camera 1! 

Repeat, going back to Perspective view and moving your view to looking down on the ship, then Create>New Spotlight>use Perspective View, and you've created another spotlight with that top view! Get the idea? Each spotlight will be in Parameters for you to tweak. 

kaotkbliss

I'll have to check my numbers to be sure, but I think they are correct. Anyways, I keep thinking to myself every time I check the render "this can't be right"

 

I did a quick space scene not long ago (just a simple one) the planet earth, an alien spaceship and a space background. The only lights I used were the sun node (had to adjust it's position (time of day and latitude/longitude) until it shined where I wanted it to, and a few emissive lights for the spaceships lights and engines.

I think the key is getting the sun node in the rnder settings in the correct position to light everything you need, also be sure that the camera headlamp isn't turned on as that will affect your scene as well.