Lighting woes in rendering

[Mike D]

I am having fits trying to get my lighting right for rendering, but nothing seems to work. At first, using the 4" recessed lights, with 75 watt bulbs, I can get a good render but only the floor and objects on the floor are lit......the ceiling is dark except around the fixtures with the Z axis @ -7/16" making bright white circles around each fixture......looks crappy.

So I adjust the z bulb position to minimum, center or maximum and the floor may look great, and other objects, but the ceiling isn't even visible.

I then tried to place some invisible lights 5' off the ground, but it's almost like they cancelled out the lights from above because then the floor was dark. I am trying a short animation path now using only invisible lights 5' off the floor to see how that looks.

Should one expect the 3D Real View render to be close to an animated render?

Using daylight on
Level 3
Brightness 1.00
Sun set at noon
Antialiasing @ 4


No luck on the above last test.....?? the room is dark.

[Allan Chesney]

Hi Mike,

Your subject line hit the nail right on the head!!  There are many.  I would suggest you read two topics on the forum first (if you have not already done so) http://forum.turbofloorplan.com/index.php/topic,117.0.html Page 2, and http://forum.turbofloorplan.com/index.php/topic,80.0.html as these cover many of the issues and some work arounds.

A few additional comments based on your remarks.

I never touch the Brightness setting, certainly not up, as I usually have great difficulty keeping the light down.  Most globes I have set to about 1 watt(!) but it seems to be different on different PCs.  I hardly ever move the light source either. 

Recessed lights will always throw the light down so they need to use light bounced off the floor to light the ceiling.  Quality setting is critical, three being a minimum to get ALL the lights to actually turn on.

I always have to shut the program down between each render or it just gets brighter and brighter washing out to totally white on the 4th time.  Restarting resets it - real pain but it works. 

Having the sun on or off affects the interior lights even if there are no windows!!!  Mine will not render (Advanced) at all with Hardware Acceleration on.

The Real View render should be much better than the Animation render (unless you are using radiosity for the animation but that would take hours I would imagine).

The good news is that a patch is on the way to fix these issues but the bad news is that we don't know when it will be!!
Experimentation in the meantime is the only solution and questions here.  It can do a beautiful render but a bit fiddly.  See the three example renders under General Discussion headed GALLERY...

Allan

[Mike D]

The redering I have been doing is for animations, and in a 15' x 32' Kitchen dining area in the plan I have 15 count 'em FIFTEEN 4" recessed lights with 75watt incandecent bulb, in the 10' ceiling, and the render (radiosity then raytrace) is beautiful from 5' down to the floor.......all else is dimm, and the ceiling is black. Like i said before if I try to place some up shining lights 5' up on the walls, but then they cancel out the recessed lights and the floor is then too dark.

After about 30 attempts to make changes which give a glow to the ceiling, I've only been able to achieve it by modifying the ceiling paint by upping the emissive effect...........

The repeated renders I've done are all just an animation path, which runs about a foot or less just to make the trials only take a half hour or so.

Below the pics show the problems in order as described above, then the last one is where the paint on the ceiling was made more emissive.
Mike

[Doug.S]

I fully empathise with you as I have gone thru the same render problems.  The solutions always seem to be trial and error and what works one time does not work the next time. Logical changes, one thing at a time, do not always work either. Frustrating but eventually I have solved all but one problem...faceted curved surfaces like a sink bowl never renders as smooth.

I'd try these things:

- keep trying emissive ceiling...even ridiculous high settings....sometime 1% works and sometimes it takes 90%

- instead of invisible lights at 5', try them 1' below ceiling but set as much lower wattage

- do trial eliminations of any odd construction (maybe do a "repair")...look for mismatched walls or any imported objects.  Bad geometry causes bad renders and are hard to find except to delete, render, delete render until bad object found.  Even try without a roof...try weird stuff and you may be surprised.

[Allan Chesney]

Mike,

Dougs comments are all very true unfortunately.  I would also suggest you try to get your settings right using Advanced rendering before you try the animations - should save you a lot of time.

In the examples below I have created a room the same size as yours with 15 downlights.  The ceiling is flat white (created a new material and just set it to white), no emmissive or any other advanced settings.

Basic render was OK but lacks the life of the Advanced

Advanced render has a quality setting of 3, brightness zero, all the lights 10w only and the sun was enabled. The Advanced render still has the same white ceiling but colour bounced off the floor changes that as it does in real life.

I have included the BDL file in case you wanted to look at the settings.

Allan

[Mike D]

I guess I forgot to mention that my renders in the above pics, were all advanced, using animation, Also for those I had reduced brightness to 0.00.

I have not used basic rendering because I never saw decent results, but Allan, your basic renderings look great!!

I have attached three pics below. This is just a quick 38'x38' building, 10' walls, 10' ceilings. I had been using this room to test different emissive settings for the ceiling, and was using 3D Real View Advanced render with Raytrace. This is how I finally was able to brighten up the ceiling in the last of the above pics.


All the below pics are just to see the difference between Basic & Advanced rendering using 3D Real View. I added the wall picture frame and table for reflection purposes, and modified the 4 75 watt recessed ceiling lamps as follows, I turned two of the off, and changed the brightness of the 2 farthest from the camera to 25 watt. the funny thing is with my original room, with all four lights on and at 75watts, I get a great render!!
Brightness 0.00
Level 3
Sun Disabled
No windows or doors
Antialiasing 4

Notice how the 2 Advance renders are too dark with just two 25 watt bulbs
Pic 1 is just Basic (raytrace)
Pic 2 is Advanced, no raytrace.
Pic 3 is Advanced with raytrace.

[Allan Chesney]

Hi Mike,

I find the brightess difference between your images unusual - why not post the file so I can try it?


Allan

[Mike D]

Posted!

Mike