Lightbox Effect?

[2dhipoo]

I'm trying out the demo version of Twilight Render on Sketchup Pro 8.

Right now I'm trying to simulate light boxes in a central business district streetscape. It took me a while to figure out a solution, but I'm using the Light Emitter template for the lightbox (I was trying to use a light within the box before). But the rendering is taking a long time, already past half an hour and it's not projecting light from within the box. I mean, I want the light box to cast light and their associated shadows and not just glow, as what it seems to be doing right now. What am I missing?

Also... I very much would like an evening ambiance but I've set SU to 2pm in the afternoon. Why is the scene so blue?

[Fletch]

Light emitting surfaces take a long time to resolve/render with biased methods like render settings 1-7. They work best with Easy 09 and Easy10.

For faster method - you will want to use this technique:
Subject: Light Bulb - aka "Come on, baby, light my bulb!"
see also these topics about lighting:
Subject: pointlight / light emitter
Subject: Diagram of a Spotlight

A great place to learn about lighting is:
Subject: Best Of Tips and Tricks - The Master List

Any sky gives blue light (even in real life) - this is why shadows are always a little blue... but the physical sky in Twilight changes depending on time of day.
Subject: Bye-Bye Blue Sky

But I would suggest some creativity with the physical sky to get an evening effect:
Subject: Moonlight Effect with Twilight's Physical Sky
Subject: Default Sky Setting for Twilight... and speed up SU

Evening Sky? Try a Late October Sky (assuming Boulder Colorado location) at 4:45pm, then DISABLE THE SUN in the Twilight Sun/Sky Dialog. Leave Physical Sky on.

this may or may not help:
Subject: Experiments with evening lighting

[2dhipoo]

oh dear. I was hoping for a radio button or checkbox solution but thank you Fletch. What's the average learning curve time needed to reach a fair level of expertise in Twilight?

[Fletch]

To do very basic rendering, about 10 mins. I know 2 9 year olds that render with Twilight. They just build, and hit render.

To do advanced lighting setup will take some practice and experimenting. People who purchase Twilight get a free packet of many different types of lights to download. Then one can use them right away to start nearly any kind of light component in Twilight. They come with a video tutorial and everything. There are many free things for licensed users, many tutorials, scenes to learn from, etc.

I would say lighting is the "hard" part - but it's not because of Twilight, it is the same with any rendering. Lighting is most important, and most difficult.
The most difficult type of scene to light is, for me, an evening shot. (So you picked a nice scene to start with. )

If you have any question, you can post, and we will try to help.

Here are some starter light components for you:
Subject: Can Light and 2x2 or 2x4 Standard Ceilight Light Components
Subject: 5 IES Spotlight effects (including SU model and IES files)

[Fletch]

Here's a quick "sketch" of the look you are going for, please open the file and render with Easy 05 Medium +, and let us know what you think.

It uses 2 spotlights inside.

streetlamp-glowing-Medium+RenderSetting-30s.jpg (109.93 KiB) Viewed 13753 times

[Fletch]

Here is a rendering with pointlights and spotlights disabled, and the emitter material only supplying the light. (+sky of course)
Rendered with Easy 09.

[2dhipoo]

Wow! You actually made a copy of the model???

The most difficult type of scene to light is, for me, an evening shot. (So you picked a nice scene to start with. )

Yes, well... I need/ed to test the capabilities of Twilight Render; best way to do this was to dive feet first into the deep end. So far I seem to be floating Night rendering is of second greatest interest because we can either do an inaccurate but fanciful rendering in Photoshop or outsource it to a rendering company. The greatest interest is accurate and quick shadow studies. Clients get finicky about those tree things being close to buildings you know...

Alright, so to get a lightbox I can either use one rendering option with lights or another without? From what I tested out on my own, I definitely like easy render 05 because it's fast (seconds versus 20+ minutes) but it seems that easy render 09 has warmer colors. Note that I took out the grille just so I could concentrate on the lightbox itself.

So here's render 05 without lights, using your settings:

light_emitting_test_render05_06s.jpg (87.81 KiB) Viewed 13522 times

Next, while not changing any settings or adding lights, I rendered with 09:

light_emitting_test_render09_22m.jpg (266.08 KiB) Viewed 13517 times

Then I added lights; according to your settings the box did not project enough light out so I upped size to 6 and strength to 8 and used three point lights and no spots:

lightbox_render05_3pointlights_6size and 8str_39s.jpg (114.39 KiB) Viewed 13518 times

And finally, I reached the attachment post maximum but I did another render09 to compare with lights ON but it looks virtually the same with render09 lights OFF. There's probably an FAQ referring to this, isn't there?

So... how can I make easy render05 look warmer?

[Fletch]

So... how can I make easy render05 look warmer?

Change the color of the light source in the settings for the pointlight.
You only need 2 point lights, not 3, just change the power of the light to get it stronger.
Subject: Color of Lights / Light Render Speed Comparison

[2dhipoo]

Thanks Fletch. This design got thrown out soon after my last post so I stopped working on lightboxes. It was a good tutorial for me for Twilight though However, I did use what you suggested (using fake emitters) in another render and I was able to get a good lightbox impression without taxing render time on prelim (this one has zero pointlights inside the box with fake emitter set to 300):

lightbox dusk crop.jpg (38.97 KiB) Viewed 13359 times

[Fletch]

Very good. but if it's producing light, then it is not a fake emitter and it is taking long to render. The material must be set as shown above.
The easiest way for a fake emitter lamp material is to use the "Lampshades Fast Fake" Material Library provided with Twilight.