External Night render

[Glenn Massey]

I have been trying to set up a night scheme looking in at an office which is lit by internal lights.

I was hoping I would just have to turn the sun off but, I have tried everything and appear to be going around in circles.

 

I would appreciate any help!!

 

Regards

 

Glenn

[Roy Hirshkowitz]

What are you getting?  Attach a picture if you think it will help.

[Glenn Massey]

[Glenn Massey]

I updated this with spot lights, seems slightly better, but not there just yet!

 

[Roy Hirshkowitz]

You're getting the idea.  Some hints:

• Use the Brightness control to alter the overall scene brightness.  This normally needs to be turned down substantially (-.30 ?) for night time renderings.
• Make sure you drawing units are correct.  Check INSUNITS, for example.
• Use accurate values for the interior lights when possible.
• Use lighting channels so you can adjust different lights in real time.

Let us know how it goes.

[Glenn Massey]

Roy,

 

What else do you think I can do with this? The lights are just washing out the image.

I have used spot lights and turned them down to 20 Watts (which seem pretty low).

 

Regards

 

Glenn

 

 

 

 

[Roy Hirshkowitz]

Follow the steps above.  Use accurate values for the lights and turn down the brightness.  Do not turn down the spotlights.  If one section is overwhelming another it's because the lighting is not accurate.

The Path Tracing is beginning to look pretty nice-- although you may be in for some long render times.  If you want to add a little ambient  you can do so by adding a tiny amount of skylight.

For example, make the sky 100% cloudy, turn it on, and set the intensity to 0.001.  Put it on it's own channel so you can adjust it to match the intensity of a night sky.

If you want some more help, you can upload the drawing and I'll take a look.

[akinlolu olugboji]

Try some of these preset.

[Glenn Massey]

Thank you I will give these a try.

 

This forum is a great help.

 

Some updated images doing as Roy suggested and changing INSUNITS to 1

 

 

[Glenn Massey]

 

Roy,

 

Would love you to take a look at the model, how and where should I upload it?

It's quite large so I can try and strip out unnecessary info.

 

Regards

 

Glenn

[Roy Hirshkowitz]

Use the link above.  It can handle 150MB.

[akinlolu olugboji]

At times a night hdri helps too.

[Roy Hirshkowitz]

This one is actually quite difficult to work with.  The units are fine (millimeters), the model however is located 1.5 kilometers from the origin.  This isn't causing any problems at the moment, but certainly may down the road.  It should be moved closer to the origin, but it was so difficult to work with in AutoCAD that I gave up after a couple of tries at selecting all of the objects.  All of this was without nXt loaded.

********

I used my suggestions above to add some ambient light.  I used channels to boost the internal lights by a factor of 100 (!) to get the internal lighting values to be more in the range of what I would expect.  The central area is too bright-- but that's largely due to uneven placement of light sources.  A standard midday sky with an intensity of 0.001 was added to produce the ambient light.  I further reduced this by about 0.2x using channels.  Your idea of using a sky with a color of black is a really bad idea.  Lots of processing for no reason.  Turn the sky off if you want to do that.  Avoid using colors to light models (I should never have offered that option.)

Anyway-- this is still a really tough rendering.  Overnight, using the path tracer: