关于NXT渲染时间的问题

[wrts5200510]

用NXT这么久，唯一的感觉是太耗时间，动辄10几个小时，甚至40几个小时还不能达到满意效果。

如图:这张图用了48个小时，但是黑点依然很多。不知道各位有没有什么好的方法能够减少时间。

[Roy Hirshkowitz]

Which engine?

[wrts5200510]

Hybrid

[Roy Hirshkowitz]

How many lights?  I'd be happy to take a look, if you like.  Zip it and use the upload link above if you're willing.

[wrts5200510]

请问您的邮箱是多少？

[akinlolu olugboji]

Here!

[wrts5200510]

thanks 

[akinlolu olugboji]

• Difficult lighting conditions I believe.
• Pull(or hide) out all the furniture, leaving the walls, floor, doors, windows and lights and hit render. 
• When satisfied with the results (also ensure the space is closed/sealed no leakages or opening to Space) by they you have an idea of the number of passes(rendering at a low resolution to save time) add the other components and do the final render.

[Roy Hirshkowitz]

One obvious problem in the version you sent me is that the units were incorrect-- inches instead of millimeters.  You can't combine natural and artificial lighting unless the units are set correctly.  For the versions below I corrected the units and changed the intensity of the artificial lights to 100 watts from 220-- I did not change the texture scaling so this is wrong in mine.  I also went to a standard sky with sun which is usually much faster than trying to light an interior with an HDRI and no sun.  I created a multi-channel rendering and placed the lights on one channel and the sun and sky on another. 

There are some minor additional things to consider when rendering:

• For the hybrid engine, glass in the openings can actually make the calculation go faster.  Not sure if it would help in this case.
• Don't use omnidirectional lights for spot lights-- use the spot or diffuse pattern.

After about two hours this is what I got-- combined, lights only, daylighting only:

[wrts5200510]

Thank you very much for all you say, I had not considered. These points. You helped me very much, thanks again. In China, the units are in millimeters, have been accustomed to, converted into inch more than one procedure. In addition, convenient for you to change the model to send my mailbox? [e-mail]

[Roy Hirshkowitz]

Working in millimeters is just fine-- but you must make sure the drawing units in AutoCAD are millimeters.  DDUNITS or INSUNITS commands will work for this.

The model is a little too big to email-- send me a private message with a dropbox or equivalent address and I'll upload my version to you.  I left it running overnight:

[wrts5200510]

我用Path Tracer渲染顶上的灯带没有，请问你是怎么做到的？

[Roy Hirshkowitz]

Again, not exactly sure what you're asking.  

My example used the hybrid engine, I would recommend it.  

In the model you sent, you did not use light sources for the ceiling indirect cove lights.  Instead, you used a material with glow.  What you see in the rendering is a glossy reflection of the glowing lamp.  This is not correct.  Use omnidirectional source for an improved simulation, but do realize that this type of lighting will result in significant noise and can take a while to resolve.