Reflection takeing forever to compute

[pradipta]

I am working on a scane where I used reflection on the floor with moderate quality setting. While rendering at 2010 resolution it is taking so long to render. 128 bucket is taking around 35 minutes in a 2Gb Xeon machine. Is there any way to reduce the computation time while using reflection?

 

thanks for your time,

[MandelbrotJr]

Are you using blury reflections? How many subdivs are you using (if using blured refls) ? What are you reflecting ?

Post a sample so we can take a look at your scene..

[pradipta]

MandelBrotJr, thanks for your help.

 

here is the sample. this sample is render using low res and low sampling.

 

i want the light coming through the window at the back to cast reflection on the floor. yes, i am using only 0.99 blurry reflection. i am rendering above 2000 resolution. and for light i am using 2200 subdiv for vray lights. i am getting good quality in other areas.

[JamesTaylor]

2200 subdivs seems massive for vray lights considering they are set at 8 by default! Do you really need it that high?

[MandelbrotJr]

Yes I agree, 2200 should be an overkill for almost any scene. I suggest lowering your subdivs and also trying to isolate the issue. For example, if you think the reflections on the floor are causing your scene to render slow, try assigning a flat material to it and see if renders faster, maybe it's more then the floor.

Regarding reflections, if you are using IR, try using "User Interpolation", it's a great way to speed up the reflections and you can get almost the same quality..

[manta]

Ya, I'm no expert, but that has to be way too high, have you tryed using like 100 subdivisions ?

[AJLynn]

35 minutes for that scene is not unreasonable. Agreed, that subdivs setting is too high, but you've got GI, IES, blurry reflections, the resolution is fairly high.

 

Or did you mean 35 minutes per bucket?

 

BTW, the real reason I'm replying - I remember that scene from a while back, and I like this version a lot more. Great improvement here. But you still need to light the balcony. Try some lights off camera so you get just a bit of glow in the back.

[Ernest Burden III]

I remember the scene, too. Liked it also.

 

Pradipta, its not required, but why not fly your flag? Show your national colors!

[Ismael]

Vray lights default to 150. It is the shadows that default to 8. So, what is set to the number?

 

Ismael

[manta]

what defaults to 150 in the vray lights ? mine default to a multiplier of 30, and the sampling defaults to 8 subdivs., he must be talking about the sampling...

[pradipta]

thanks for all the great response.

2200 I set from the 'Diffuse Subdivis' from the VRay Light Properties under VRay System panel. This generally stay 150 at default. 'Sampling Subdivs' I kept at 50, default is 8.

Martin, yes, i checked the 'User Interpolation' parameter

Andrew, it's 35 minute per bucket of 128 for a render resolution of 2010 pixel. Nice to see you liked this version.

Ernest, I will check that from my profile. Thanks

I am attaching a test from my render. This is cropped from the actual 2010 pixel file. I used a low samplings for this one. i kept light DiffuseSubdivs at 1500 and Sampling Subdivs at 30. Also reduced quality from IR parameter, QMC parameter. I marked a region using red, computation stucks at this point almost for 60 percent of time.