Iray Light Question?

3Don

I have bought some Iray lights from the store and am not getting very satisfactory results (and very long render times). I assume there is an Iray render default setting, so when I install new Iray lights and load them, what other settings do I need to change (to match the light qualities)? Or, do Iray lights change other settings once they are loaded?

There are all kinds of new settings for different render apsects that I am not very familiar with. 

fastbike1

As far as long render times, a couple of things to consider:

1 Do you have an Nvidia Graphics card that supports CUDA?

2 If you do, is it selected in the RenderSettings>Advanced>Hardware tab? It should by default but doesn't always do so.

3. If the above are true, does your scene fit in the cards VRAM?

Are the lights emissive? If so, they take longers to render than photometric lights (spotlights, point lights).

Do you have the Iray Renderer slected?

TheKD

As far as looks go, you need to adjust the camera settings in tone mapping. if It is doo dark, try lowering the fstop by two, until it's light enough. If it's too light, turn fstop up. You can also brighten it by raising iso, and darken by lowering. Mesh lights look really nice with soft shadows, but take longer to render.

3Don

fastbike1 said:

As far as long render times, a couple of things to consider:

1 Do you have an Nvidia Graphics card that supports CUDA?

2 If you do, is it selected in the RenderSettings>Advanced>Hardware tab? It should by default but doesn't always do so.

3. If the above are true, does your scene fit in the cards VRAM?

Are the lights emissive? If so, they take longers to render than photometric lights (spotlights, point lights).

Yes I have an Nvidia card (Mac )S10). What is CUDA?

I'll have to check on Render Settings and what kind of lights (but I think they are emmisive). Thanx for the comments.

Do you have the Iray Renderer slected?

 

SpottedKitty

What kind of scenes are they for, interior or exterior? Exterior light sets seem to be mostly HDRI Environment lights; these should slot right into the map setting in Render Settings>Environment and you shouldn't need to do much more (although see below).

Interior lights are generally supposed to be just like real-world interior lights: a lot less powerful than exterior ones. This means the scene will be dimmer, so you have to compensate for it. Look in Render Settings>Tone Mapping and try tweaking the parameters that correspond to camera controls. Not the cameras in your scene, an actual real-life camera. This is where the root of the problem is, the default Tone Mapping settings are for a bright, sunny day using the default Environment map. If it isn't a bright sunny day, then you must adjust the Tone Mapping camera parameters.

Note that this can also bite you when you're using an exterior HDRI light, and it happens to be a "night" or "twilight" light.

Tobor

There are a number of Iray light products for sale that shouldn't be. Just because Daz is selling it doesn't mean it's any good. You do mention you believe the lights are emissive: this is actually a poor choice for producing scene lighting. It's not necessary, and it can greatly increase render times unless you have a very robust system. Emissive lights are best used as in-scene elements, lights you see in the render, rather than just lights that produce illumination, for selected accenting, and various types of special effects.

Frankly, you are better off starting with the default HDRi "Ruins" scene, and learning lighting techniques from that. Add some spotlights or pointlights, and experiment with them. Remember that with both, you can increase the size of the emitter surface, which soften the shadows produced by the lights (the emitter size is indicated in centimeters, so '100' is a one meter emitter).

After learning the ropes you can buy a package set, but trying to learn about Iray lighting by using a product that may or may not be designed well can often lead to frustraion.

3Don

I was mistaken, the lights I used are not emmisive. Where is the default Ruins scene to be found?

Tobor

Just hit the Default button in the Iray render tab. That should return everything to the defaults, and you can work from there.

If not emissive, then what kind of lights are they? 

evilded777

Tobor said:

There are a number of Iray light products for sale that shouldn't be. Just because Daz is selling it doesn't mean it's any good. You do mention you believe the lights are emissive: this is actually a poor choice for producing scene lighting. It's not necessary, and it can greatly increase render times unless you have a very robust system. Emissive lights are best used as in-scene elements, lights you see in the render, rather than just lights that produce illumination, for selected accenting, and various types of special effects.

Frankly, you are better off starting with the default HDRi "Ruins" scene, and learning lighting techniques from that. Add some spotlights or pointlights, and experiment with them. Remember that with both, you can increase the size of the emitter surface, which soften the shadows produced by the lights (the emitter size is indicated in centimeters, so '100' is a one meter emitter).

After learning the ropes you can buy a package set, but trying to learn about Iray lighting by using a product that may or may not be designed well can often lead to frustraion.

+10, may I quote you sir: "There are a number of Iray light products for sale that shouldn't be."