Complex reflections and render time

Hi all,

I’m having a bit of trouble with blurred ray mirror reflections and the render time for them. I need a surface to have faint, very fuzzy reflections, and have achieved this using the Gloss option in the Ray Mirror settings. Unfortunately the results have a lot of noise unless I put the number of samples up to a large number.

For the example settings (Gloss = 0.6, Samples = 64 - see RayMirror.png), I get a fairly decent result, but the render time is very high (around 7 hours with OSA), and there’s still a fair amount of noise in the dark shaded area of the cutout section. I could cure the noise by increasing the sample count, but I dread to think what would happen to the render time.

Can anyone suggest an alternative approach to achieving this effect while keeping the render time down to something a bit more manageable? Perhaps the Threshold option is the key, but I haven’t really figured out what effect it has, so I’ve left it alone so far.

By the way, the long render times include the lighting rig I’ve got set up for the scene (ambient occlusion & soft shadows). However, the render time is still a pain with basic lighting.

Thanks in advance,

PS I’m new to this texturing lark, so it’s perfectly possible that I’ve missed something obvious.


I’ve experimented very little with glossy reflections, but couldn’t you just do the reflections as a separate render pass and then blur it a bit in the compositor? Then you could lower the samples even further.

Thanks for the hint - I’ll check out that feature. Having only ever mucked around on the edges of Blender before now (this is my first proper image), I didn’t even know such things were possible.


Don’t even use reflection at all, simply map some chrome kind of texture to the reflection slot. This short cut has been used for years. (ie Pixar\ILM etc…). When faced with realistic deadlines, you have to have realistic render times.

instead of using the mirror ect,

why not put a texture like crhome on the faces where needed

this should do the same job but a lot faster

go to the 3D repostiory of blender and download the chrome texture
and define a new material fo teh object if needed then apply the texture
where you need it

another way would be to use yafray which is very good for mirror surface and probably faster the blender

or may be use the yafaray renderer which is more modern than yafray but requires installtion ect,

Blener renderer is a specialist at cheating reality and it does represent a lot a ittle tricks to learn
but the results is that the render time is usually faster


The theshold value is at 0.000, set to something like 0.100 or higher

I rendered out a red cube on a very blurry reflecting plane and it only took 30 seconds on my quad core, my settings was 300 samples and the threshold at 0.150.

Thanks for the suggestions, people. I’ll do some experiments and see which solution will work best.