Author Topic: Simulate an LED light pipe scenario  (Read 209 times)

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Offline JOEYMAC

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Simulate an LED light pipe scenario
« on: October 04, 2019, 02:36:38 pm »
Hello,

I am a toy designer and I use clear plastic light piping on my toys that is accompanied with led's.  In the assembly I assign a clear plastic to the light piping plastic but how can I add a light to the scene to light up the light piping plastic? Any help would be great!  I want to simulate it in Keyshot not PSD like I usually have to do.   The plastic is too dark in the key shot renderings and not lit. 

Thanks in Advance!!

Joe


Offline MWo

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Re: Simulate an LED light pipe scenario
« Reply #1 on: October 05, 2019, 02:12:06 am »
Hey and welcome to this community.


This topic was discussed several times here. So the search will give you many examples and tips to achieve, what you’re looking for.
There are fast, quick and dirty solutions. And there are accurate and photorealistic solutions that costs some render time.


For the pipe I would use a dielectric material instead of plastic or an advanced type.
The LED’s can be represented as small objects as a base of the light material.


It is important to use real life scale. Otherwise you have to in- or decrease the Lumen value of the light material.


Rendering to a 32bit PSD would help in post.


Hope that helps to find your track.


Cheers
Marco


PS: weiter in short form on a mobile.

Offline JOEYMAC

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Re: Simulate an LED light pipe scenario
« Reply #2 on: October 07, 2019, 09:36:22 am »
Thanks MWo,

A dielectric material is plastic, glass or ceramic.  I have tried using glass and plastic for the led light pipe itself.  For the leds just assign an LED to another object behind the light pipe plastic?  I will try that.  Is there a package that is uploaded to this forum that has light piping used in the scene?  That would be so helpful.  Thanks for your help!

Joe


Offline NM-92

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Re: Simulate an LED light pipe scenario
« Reply #3 on: October 07, 2019, 11:36:18 am »
It is also important to use the "product" lighting preset. This mode let's light go through transparent objects by increasing the light bounces or so

Offline JOEYMAC

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Re: Simulate an LED light pipe scenario
« Reply #4 on: October 08, 2019, 11:17:59 am »
Thanks for the tips!

Offline DetroitVinylRob

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Re: Simulate an LED light pipe scenario
« Reply #5 on: October 10, 2019, 06:29:56 am »
I hope you might find some utility in this...

It's all a question of what your customer anticipates and how much time you have but...

First off, most light pipe scenarios present with a LP encapsulated in a dark housing environment, the inside of your product body, often they also need a closeout panel/reflector behind them that is usually molded white plastic or chromed to brighten up the LP and limit a peak-through condition. Often there is an additional outer lens (sometimes with optics or texture) above the LP on first surface. All these modeling things add realism. Be accurate with material thicknesses in you CAD modeling. I also highly recommend Global Illumination with a bounce count that is increased beyond the exact number of reflections/refractions in the physical part. TRY MORE until you reach diminishing returns (secondary and tertiary bounces add tonal shift, highlight detail, and dimensional transparency).   

I highly encourage you to utilize "dielectric" material (abbe/refractive index) for your light pipe(s) and add an IES-light at the focal point of your LED if at all possible for the most realistic presentation. IMHO it is worth the extra effort and will keep your product presentation from appearing 2D and cartoon like. And you really should not shortcut on using real material specs. Ks is designed to perform accurately to real material properties.

Here is a good resource for relevant material specs: https://refractiveindex.info/?shelf=organic&book=polycarbonate&page=Sultanova

(I have been a transportation/product designer for over forty years, twenty one of it as a lighting designer, and over ten years in ray-trace based rendering. Our product work MUST be photo accurate and repeatable for approval by all the major automotive brands on the planet.) Just saying
« Last Edit: October 14, 2019, 06:12:04 am by DetroitVinylRob »

Offline TGS808

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Re: Simulate an LED light pipe scenario
« Reply #6 on: October 10, 2019, 04:48:56 pm »
I hope might find some utility in this...

It's all a question of what your customer anticipates and how much time you have but...

First off, most light pipe scenarios present with a LP encapsulated in a dark housing environment, the inside of your product body, often they also need a closeout panel/reflector behind them that is usually molded white plastic or chromed to brighten up the LP and limit a peak-through condition. Often there is an additional outer lens (sometimes with optics or texture) above the LP on first surface. All these modeling things add realism. Be accurate with material thicknesses in you CAD modeling. I also highly recommend Global Illumination with a bounce count that is increased beyond the exact number of reflections/refractions in the physical part. TRY MORE until you reach diminishing returns (secondary and tertiary bounces add tonal shift, highlight detail, and dimensional transparency).   

I highly encourage you to utilize "dielectric" material (abbe/refractive index) for your light pipe(s) and add an IES-light at the focal point of your LED if at all possible for the most realistic presentation. IMHO it is worth the extra effort and will keep your product presentation from appearing 2D and cartoon like. And you really should not shortcut on using real material specs. Ks is designed to perform accurately to real material properties.

Here is a good resource for relevant material specs: https://refractiveindex.info/?shelf=organic&book=polycarbonate&page=Sultanova

(I have been a transportation/product designer for over forty years, twenty one of it as a lighting designer, and over ten years in ray-trace based rendering. Our product work MUST be photo accurate and repeatable for approval by all the major automotive brands on the planet.) Just saying

Hey Rob, I've seen you chime in on these "how do I do LED lights" threads in the past and you always seem to have good advice about how to get it done right. You've also mentioned before (and above) that your product work specifically needs to be photo accurate when it comes to LEDs and lights but I don't think you've ever posted any of your work here (at least not that I recall seeing). If you're allowed to post it and if you don't mind, I'd be interested in seeing your results. I'm sure others would too. Thanks!

Offline DetroitVinylRob

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Re: Simulate an LED light pipe scenario
« Reply #7 on: October 11, 2019, 05:30:34 am »
I'd really like to post some render example realizing possibly how valuable it might be to see the differences. The issue is almost all of what I do is based on proprietary customer data and just isn't something I can display. Have been trying to work on some generic example. My apologies