help with Iray graininess and speckle

Ademnus

if I place a figure or so in an environment and take a render, everything is very speckly with noise, no matter how long I let it render. if I render JUST the figures, they are fine. I'm assuming it has someting to do with the shadows created by the environment. How do i deal with this?

cm152335

if shadow,,
click on "lamp" check "parameters" of the actual lamp,

do the same for all lamp

Ademnus

that really doesnt help :(

cm152335

you are in perpective view or camera?

remove all light to check if the light is the main guilty.

Richard Haseltine

What do you mean by an environment?

Ademnus

Richard Haseltine said:

What do you mean by an environment?

Like an interior set such as an apartment.

Richard Haseltine

That is going to block alll external light, in whole or in part depending on how it iss et-up. You are getting noise because the light has to find its way in through any openings (windows or doors, or hidden walls) and then bounce around inside to illuminate surfaces not facing an opening - that means it takes a lot more rays to converge. Using lights in the room will help, though of course the result will look different.

Ademnus

Richard Haseltine said:

That is going to block alll external light, in whole or in part depending on how it iss et-up. You are getting noise because the light has to find its way in through any openings (windows or doors, or hidden walls) and then bounce around inside to illuminate surfaces not facing an opening - that means it takes a lot more rays to converge. Using lights in the room will help, though of course the result will look different.

Thanks, richard, tho I do generally set lights inside too. I'm wondering if I need to mess with any settings like 'crush blacks' or fstop.

Richard Haseltine

Although the Tone mapping can have a very small impact on noise, in my experience (others deny it does anything), the main issue is getting enough light paths in there - Tone Mapping can help you to pull the effect back if you end up having to overlight.

Ademnus

Richard Haseltine said:

Although the Tone mapping can have a very small impact on noise, in my experience (others deny it does anything), the main issue is getting enough light paths in there - Tone Mapping can help you to pull the effect back if you end up having to overlight.

Thank you, sir. I shall experiment.

barbult

You might want to consider adding Iray Ghost Lights to your scene. Here is the forum thread about them.

SoundLufs

Is there an example to see, how it looks like?

AndyS

Yes, there is.

But I didn't use the referenced product, cause I did this trick by my own since ever.
--> http://andysanderson.deviantart.com/art/GhostLights-Compare-659336751

Ademnus

barbult said:

You might want to consider adding Iray Ghost Lights to your scene. Here is the forum thread about them.

Gave them a try and now cannot live without them. ;) Thanks!

nonesuch00

The easiest way I've found it to light the environment with an HRDI but to not 'draw the dome'. Renders faster and with less speckles. You must find good HRDIs and it's somewhat problamatic to find HRDIs at the right time of day, correct latitude & longitude, correct weather conditions, and correct geographic features to create the light you want still the light they make are very good.

Tobor

nonesuch00 said:

The easiest way I've found it to light the environment with an HRDI but to not 'draw the dome'. Renders faster and with less speckles. You must find good HRDIs and it's somewhat problamatic to find HRDIs at the right time of day, correct latitude & longitude, correct weather conditions, and correct geographic features to create the light you want still the light they make are very good.

Remember that you can rotate the dome to point its main light in any direction. Set the dome to Finite Sphere, and additional controls appear. The Rotation setting controls the azimuth of the dome, which is often all you need. For example, if the light points west, but your camera is pointing at characters toward the east, their faces will be in shadow. Rotate the dome 180 degrees and now they'll be fully lit.

As required you can alter the altitude and change the height of the lighting. This makes the lighting come in more shallow or steep. Just remember this won't alter the quality of the light. A light source low on the horizon -- i.e. at dusk -- is typically "warmer" due to the increase in atmosphere. You won't get a change in color simply by altering the direction of the dome.

nonesuch00

thanks