Need to light a sign

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TSPCo
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Joined: Thu Jan 12, 2012 1:48 am

Need to light a sign

Post by TSPCo » Fri Feb 24, 2012 3:41 pm

I have a sign on a model, in real life it could be lit from within, with fluorescent lamps. Lit from outside with fluorescent lamps shining on it.
Here is what I tried so far, an 8' fluorescent ies from below, and above. I get bright spots that look like point lights 8 ft apart, not right.
I tired a emitter material on the surface of the sign, long render time. I tried a lampshade material (which I really do not know how to use) long render time no light. Subsurface scattering (wax) no light output. I really need a fast simple solution. Along the same lines perhaps some pointers on using long lamps and ies. The 2x4 troffers I used inside this same model look great, using the twilight light components.
I will keep trying things on my own but some ideas would be of great help.

derei
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Re: Need to light a sign

Post by derei » Fri Feb 24, 2012 3:48 pm

Please show us some visuals of what you did... or better, share the model. Also, a visual of what the result are you expecting can help.
ARTIST AND DESIGNER DEREI.UK

TSPCo
Posts: 66
Joined: Thu Jan 12, 2012 1:48 am

Re: Need to light a sign

Post by TSPCo » Fri Feb 24, 2012 4:19 pm

First version with IES file from an 8' fluor fixture. Perhaps is it the position on the ies light, that is giving me trouble.
Attachments
signwall.skp
(264.2 KiB) Downloaded 565 times

derei
Posts: 470
Joined: Fri Nov 26, 2010 3:11 pm
OS: WIN7 Pro x64
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Re: Need to light a sign

Post by derei » Fri Feb 24, 2012 5:39 pm

This is what I did using a fluorescent tube.
Try to think as in real life. If you want to use spot lights (or IES), consider to put it at the end of a metallic arm which will keep the light at a distance from wall and oriented trough the wall. It can be positioned above or under the sign. Because putting a light so close to the wall will cast burning lights to the wall and will lit the sign only from below. So it's no way to have the light reflected from the face of the sign.
Also, consider a ambient light... even in the darkest night, there is a small ambient lighting (stars, moon, city lights)...
Attachments
no ambient light
no ambient light
2012-02-24_191517.png (316.1 KiB) Viewed 11727 times
with small ambient light
with small ambient light
2012-02-24_192102.png (523.12 KiB) Viewed 11730 times
signwall.skp
the scene, changed
(269.65 KiB) Downloaded 567 times
ARTIST AND DESIGNER DEREI.UK

Fletch
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Re: Need to light a sign

Post by Fletch » Sat Feb 25, 2012 1:40 am

Fastest rendering with Easy 1-7 (even works with 8) is to paint the front face of the letters with a unique material/color and set that material to be an emitter, but change the emitter type from "Normal" to be "Fake".

In real life, that sign would not be sufficiently lit with a fluorescent light under it as built in the example model supplied above. Normally several spot lights are hung out from the wall to shine back onto the face of the letters. In that case, start with a spot light provided in the free Twilight Ligh Components and adjust as needed. turning on Physical Sky and setting it to intensity of .25 is a good quick evening sky setting.

TSPCo
Posts: 66
Joined: Thu Jan 12, 2012 1:48 am

Re: Need to light a sign

Post by TSPCo » Sat Feb 25, 2012 1:47 am

I ended up using two IES based facade floods on the sign area, and added two more of the same on each outside edge of the building for a better balanced look. Not perfect but it looks OK. I will try your approach as well.

Gareth
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Re: Need to light a sign

Post by Gareth » Sat Feb 25, 2012 2:53 am

if the sign is 3D, lighting it from underneath will produce unwanted shadows

here is a quicky using fake emitters on the signage, and another invisible fake emitter sitting in front of the sign
Attachments
TW Screenshot.JPG
TW Screenshot.JPG (76.62 KiB) Viewed 11705 times

Fletch
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Re: Need to light a sign

Post by Fletch » Sat Feb 25, 2012 3:57 am

Fake emitters are only fake if rendered with Easy 1-7
They actually emit light in Easy 9 or 10 (MLT or MLT/BiPT in Kerkythea)
This is not a problem of any kind, but it should just be understood that if a fake emitter is applied to something with a lot of triangles (like these text signs) then in Easy9 or 10, they become 100s of lights, and may effect render times accordingly.

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