how to cut down the render time

[nominds]

hi

This took 82 hours in a (intel xeon 3.8 GHz) dual processor ibm machine with 2GB ram and 512 MB nvdia GAC.


Render size 4000x3000.
Other views of this project rendered at an average time of 2hrs at same size.

I tried use interpolation option, but the brushed steel effect was too bad.
but render time came down to 15hrs.

any sugestions?

[free4all]

Hi Nominds

I would try increasing the reflection glossy subdiv to atleast 16 and also seeing as you are using lightcache. Tick "use light cache for glossies."

Might be worth swtiching to "adaptive QMC" for the image sampler. I find it better with large amounts of glossies although you may need to decrease the noise threshold to compensate for the extra noise. Only do that if noise is an issue.

Image is looking nice, hopefully that will help

[neha]

nominds, these are a few things you can do:
*For all the materials, with reflections, reduce the Max depth to 3. If its applied to some small object hardly seen, like for eg. the metal on chairs behind the counters, you can take it 2.
*If you are using vray 1.5, then you can increase the noise threshold settings, I think 0.03-0.05 should be fine, this will cut down the render time.
*I feel you will also get away with higher values for the min and max rate for IR.

I hope this helps.

[pradipta]

nominds, I recently worked on a big size commercial interior spaces and had to do lots of r&d in finding the proper balace of quality and render speed. Some of my observations are:

- if Relf Glossiness is made below 0.9 it will slow down the rendering considerably. If there is not much change in the reflection output then its better to keep in in the range of 0.9 to 0.93. Max Dept of 8 is ok in most cases.

- under global switch the default reflect/refract and transparency depth can be reuced. in most cases you need 4 max depth and 15 transparencey levels.

- keeping the LC sample size big sometimes help in reducing the overall calculation time

- "use light cache for glossies" is a good time saver at a cost of minor reflection damage

This also depends a lot based on the geometry, so, lots of thing can be optimized.
-

[kiittea]

If you have a certain types of geometries which are repeating, Making Instance of copy will help in reducing file size and rendering time as well.

[raymers]

[quote=neha
*If you are using vray 1.5, then you can increase the noise threshold settings, I think 0.03-0.05 should be fine[/quote]

yeah, that is really important! I usually go for 0.02 but that depends.

Also the global sub divs is on 2. and the min. sample on the RQMC is on 10, so that means at least 10 x 2 = 20 subdivs for anything! I usually keep the global subdivs at 1 to get more control over the whole scene. Of course it can save time,in u have to adjust a whole lot, but I like to keep it at one. Also the LC could maybe go even lower, but that hasn't that much to say.

Also the size of the textures is important. Dont go higher that u have to.

good luck

Raymond

[neha]

Originally Posted by raymers

yeah, that is really important! I usually go for 0.02 but that depends.

Yes, actually its mostly a "Quality VS Time" situation...you usually have to find the right balance of settings that gives you your desired quality in an acceptable amount of time. This will also depend on whether one is doing stills or animation...in animations one would prefer to cut down the render times on cost of quality...and the other way round for stills.

[d.sign]

All that is been said is good, I would just add replacing all the possible area lights with luninous geometry cut down time drastically!

[nominds]

Thank u alll, for the valuable suggestions....