Cycles settings / results...


i modeled some stuff to test CYCLES but im getting some troubles, dunno why.

maybe you can help me finding the problems…

this is a 1500 samples image:

this is a 2000 samples image, without “light” (only the lamp)

any idea to “improve” this?

thanks in advance.

How did you manage to get that much noise after 1500 samples?

Please tell me you haven’t put the light inside a bulb made of a glass material and aren’t trying to light the scene with caustics…

Yeah, getting that much noise out of 1500/2000 samples is a technical feat all by itself. You should win something.

well… basically its a “cilinder”, and the light is created with a sphere + emission.

Post a tutorial!

That’s a classical “tough case” for unidirectional path-tracing. Make sure to have the sphere have as few faces as possible and check “sample as lamp” in the sphere material.


check my “printscreen”.

the render was created with that option enabled…

the render used those settings…

My advice would be: add more emitters in the scene to lighten up the room. You can always darken down the image in post if you need to, but you can never increase the brightness without enhancing the grain.

Set strength of your light higher than 40 (and use a faster exposure to keep it dark, look for this in the camera settings) and experiment with Ambient Occlusion (in the world settings panel).

Also try using the various “Integrator Presents” in the Render->Integrator panel.

What does your lampshade material look like? Basic translucency?

If the only light you rely on to light the scene is mainly indirect from a small light source that is being bounced around you will need a lot of samples to make it look good.

Add some large, low-level light outside the camera’s view.

well… the thing is: this is “inside” a cube.

i dont know why i need world settings here + i dont know how to find those settings inside cycles (only in blender internal).

with more emission value i can get a “better” render, but i though i should get a “nighty render” without faking it, same as saying i didnt need to make a normal render + some post composing “night effects”.

thanks for the replies…

EDIT: this is my integrator settings:

Here, similar scene, 200 samples.

Blend file:

nice… i will see your blend file and see how to improve mine.

btw: my scene is 100% INSIDE a cube, maybe that is making some difference.

you used a totally diff king of material settings, i will test them .

thanks for the file and the patience :smiley:

The ambient occlusion settings in the world panel should still affect your render despite it being inside a cube.

Also you can add a bit of light from another large emitter somewhere inside your cube, maybe under the ceiling.

“btw: my scene is 100% INSIDE a cube, maybe that is making some difference.”

make sure the normals on the “cube/walls/floor and ceiling” are pointing inside the room.
Click the Cube tab into edit mode, press the “n” panel , for normals click the face icon(thats what it looks like on Bmesh builds)

on 2.62 builds “n” panel “display” put a check box next to Face

lmao @ rocketman and “Post a tutorial!!!”
All this starts to me remind me of the bit in “Breakfast Club” about Anthony Micheal Hall in Shop Class, trying to build a lamp that actually lights up…

Excellent scene for bi-directional integrator to see difference. That yellow cover cut Cycles direct light probes (work only with Transparent BSDF), and you get noise from indirect light because it can hit bulb very rare. I make quick test to prove that, delete all point lights, replace all complex shaders but basic diffision/emission and translucent for cover, noise on wall in case of bi-directional clean very fast (it expected, light paths starting from bulb are very dense in space near lamp), even after 10 samples. But noise on cover still noticeable and very different from uni-directional, maybe i have bug, much check.
That strange difference with Transparent BSDF hold me from call for wider testing of bi-dir patch, i hope one-two weeks later will found bug and start flooding threads with special twieaked cheated scenes that show bi-directiuonal advantage :slight_smile:

Scane by MadMinistrel, all point lights deleted, all materials are basic, yellow cover is pure translucent, light bulb emission bsdf.
Default Cycles:

Bi-dir variant:
Warning, it is not fair to compare uni- and bi- directional with same max bounce settings, bi-directional use more bounces, in my half-finished case it 1.5 more with same settings (i add only pure light->camera chain), when if will feature complete it will be more like N*N bounces, and you better compare time to clear noise then quality of pictires with same sample number.

Nice! The bi-di version is great for just over 200 samples.

But you lost the hint of the ribbing inside the lamp that way :slight_smile:

I found using a mesh emitter inside translucent lamps or even solid hanging lamp being more noisy and slow convergence, using point lights or spot gave much cleaner results. Shouldn’t be the inverse within Cycles? I knew mesh emitter would give you faster and clener results…

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