Need help with interior render.

[akinlolu olugboji]

I have this(bedroom view 11) clients wants this (photo 6) model (plan - copy) attached. help needed with materials and lighting, on wall, furniture and floor.

[Roy Hirshkowitz]

Phew.. overnight for 15+ hrs.-- not bad but still not perfect yet.

[Peter Milner]

Looks pretty close to me.

Try using path tracer, it may give that slightly softer look.

[Ros. Riha]

I like this one very much... nice atmosphere indeed...and I thought by the look of it that this is path tracer...

[Roy Hirshkowitz]

Very difficult for the path tracer to resolve this one, though.  I need more cores (32?)

[Peter Milner]

Just change the design of the building and have more windows.

[Roy Hirshkowitz]

You got it.

[Peter Milner]

Do other rendering engines have this problem with dimly lit interiors, or are there ways round it?

[Roy Hirshkowitz]

Sort of-- our standard engine handles this one pretty nicely.  This one would give Maxwell fits (I think.)

*****

It's not really the dim lighting, that part's easy.  The predominant light in this space is reflected sky light through a small opening.  That's a very difficult problem.  The light source is large (the sky) yet the opening is small.  The noise in this one is compounded by a variety of other issues:

 

• The curtains cause many of the light paths to be much more complex.
• Almost all of the surfaces have some degree of glossiness.  Glossy reflection is more noisy by nature than pure Lambertian (diffuse) reflection.
• Many of the surfaces we're interest in are multiple bounces (3-4) away from any light source.  Again, the predominant illumination is indirect.  Very few surfaces are lit directly.
• This is a true HDRi-- a small part of the image (the sky) is very bright >10000 cd / m^2.  A decent portion of the image is quite dim (~ 1 cd/m^2).  Tone mapping a scene like this can make it look noisier.
• The model is complex in terms of number of faces ~750000.  While this doesn't have a huge effect, it does slow down the ray casting somewhat.

 

 

 

[Ros. Riha]

would it not be good to try to reduce the number of faces first? On the account what I do see on the image, the number of faces seems too high to me.

The same with "some degree of glossiness" - some parts of the model do not seem to need to be glossy at all...

The rendering is nice and interesting, so I would like to see it happen and I would also like to know that it is possible to achieve this kind of quality using nXt on regular basis..

Nice job, akino and others.

[Roy Hirshkowitz]

I wouldn't-- the number of faces is probably the least of our worries here.  You only reduce glossiness if you don't want glossy walls-- otherwise you have to leave it.  The best thing to do, as Peter suggested, is to bust a few more holes in the walls.  An extra window or two would make the thing go much faster.  Pulling back the curtains would probably help-- but they're my favorite part.

Welcome to path tracing.  It kind of is what it is.  180 core hrs. gets you this.

 

[akinlolu olugboji]

Must say I love the over night thing and when next I run into this I will be sure to add openings where it will not show in the view am rendering to help the rendering along. Thanks all I must say I have learnt a lot.

[Roy Hirshkowitz]

Adding openings wasn't really meant as a serious suggestion, of course.  It just demonstrates the difficulties of rendering a daylit space with a small opening for the light.  While Path Tracing should eventually get you an answer, it can take forever if you give it a hard enough problem.