Author Topic: How to achieve realistic led glow  (Read 2762 times)

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Offline Lag

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How to achieve realistic led glow
« on: November 24, 2018, 12:10:02 pm »
Hi guys,

I'm working on creating some renders for a mouse and having trouble achieving the right looks on the leds. How can i make my leds looks like the attached file?

I know some of it it's done in post processing, but i need to make it look right first in the render and then finish it in photoshop. Right now for the LED's i'm using a 'Plastic (transparent)' as material and it looks fine but it doesn't look like a shinning led. If i change my material to 'Area Light Diffuse' it looks more like a light but it kind of breaks the realism.

Any suggestion is appreciated.


Offline TGS808

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Re: How to achieve realistic led glow
« Reply #1 on: November 24, 2018, 09:51:21 pm »
Change the Plastic (Transparent) material to the Emissive material. Emissive emits light but not as much as an Area Light. It's good for things like the small LEDs that you have on your mouse. You can leave your color gradient set up the same way that you have it now. Dial up the intensity of the Emissive material but not too high. Then in the Image tab, turn on Bloom. Adjust the Bloom Intensity, Radius and Threshold. You may have to go back and forth between adjustments for the intensity of the Emissive material and the settings of the Bloom as one will affect the other but it shouldn't take too much tweaking to get the look you want.

Offline RRIS

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Re: How to achieve realistic led glow
« Reply #2 on: November 26, 2018, 06:33:06 am »
I'm currently working on a product with a led strip behind transparent plastic, what I ended up doing was creating a cloudy plastic, then using an emitting material as a layer using a gradient set to viewing direction as opacity map (gradient goes from black to white to black). This gradient also centers the led in the strip, so that there's some room for the plastic to have highlights and reflections visible in some areas.

Online MWo

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Re: How to achieve realistic led glow
« Reply #3 on: November 26, 2018, 09:51:28 am »
I would try to use point lights und a strip of and advanced material with roughness in transmission.
Then render with caustics enabled without global illumination.
Then red up with a lot samples and adding glow.


This should look awesome.

Offline Will Gibbons

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Re: How to achieve realistic led glow
« Reply #4 on: December 07, 2018, 11:19:42 am »
Orrrr if you're using KeyShot 8, use the improved Bloom feature in Image Styles!

Offline DetroitVinylRob

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Re: How to achieve realistic led glow
« Reply #5 on: December 10, 2018, 09:57:01 am »
As a long time automotive lighting designer, I'd like to share how I view the challenge of rendering realistic LED glow.

First, there are many here on the forum that can speak about KeyShot in particular, and rendering in a broader sense, far more in depth then I. And yet, perhaps the biggest single issue in rendering realistic, life like, lit LED features that becomes brutally apparent to me, is not so much all the great rendering techniques (trickery) that one can employ to fine-tune an interesting image, as is getting the bones of the solid model correct in the first place.

Take a really good look at many (real) products that you are trying to simulate in a render first. Try to take pictures for inspiration and a record to check your work against.

Look how LED source light rarely portrays its hue and intensity as a uniform, opaque, first surface, image but rather shows as a point light source, fading its glow over distance, (physically) under a clear optical outer lens. Most LED or other lighting source elements often use parabolas (reflecting and collecting) and inner optical (refracting pillows or lightly textured) lenses to focus, pipe, and direct or disperse light. With a modest model these will give you far more believable depth, detail, and realism to the lit elements rather then winding up with a cartoonish, 2-D graphic, "Tron" like appearance.

Caveat: By design one may desire a very uniform and consistent lit appearance for their product but, the reality is rarely that controlled.

Just my two cents.
« Last Edit: December 10, 2018, 10:12:55 am by DetroitVinylRob »

Offline TGS808

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Re: How to achieve realistic led glow
« Reply #6 on: December 10, 2018, 02:26:25 pm »
Caveat: By design one may desire a very uniform and consistent lit appearance for their product but, the reality is rarely that controlled.

Which is why we like to work in the virtual world. It's easier to control than reality.  ;)

Offline RRIS

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Re: How to achieve realistic led glow
« Reply #7 on: December 13, 2018, 01:23:57 am »
As a long time automotive lighting designer, I'd like to share how I view the challenge of rendering realistic LED glow.

First, there are many here on the forum that can speak about KeyShot in particular, and rendering in a broader sense, far more in depth then I. And yet, perhaps the biggest single issue in rendering realistic, life like, lit LED features that becomes brutally apparent to me, is not so much all the great rendering techniques (trickery) that one can employ to fine-tune an interesting image, as is getting the bones of the solid model correct in the first place.

Take a really good look at many (real) products that you are trying to simulate in a render first. Try to take pictures for inspiration and a record to check your work against.

Look how LED source light rarely portrays its hue and intensity as a uniform, opaque, first surface, image but rather shows as a point light source, fading its glow over distance, (physically) under a clear optical outer lens. Most LED or other lighting source elements often use parabolas (reflecting and collecting) and inner optical (refracting pillows or lightly textured) lenses to focus, pipe, and direct or disperse light. With a modest model these will give you far more believable depth, detail, and realism to the lit elements rather then winding up with a cartoonish, 2-D graphic, "Tron" like appearance.

Caveat: By design one may desire a very uniform and consistent lit appearance for their product but, the reality is rarely that controlled.

Just my two cents.

True, but once you start modeling reflectors, lightpipes, lenses, etc. you're looking at rendertimes of hours vs. minutes. I always enjoyed simulating that sort of stuff in Maxwell Render years ago, but in the end only one thing counts in a commercial project. Does it look right? Then that's good enough 99% of the time.

Offline DetroitVinylRob

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Re: How to achieve realistic led glow
« Reply #8 on: January 08, 2019, 10:46:20 am »
True, but once you start modeling reflectors, lightpipes, lenses, etc. you're looking at rendertimes of hours vs. minutes. I always enjoyed simulating that sort of stuff in Maxwell Render years ago, but in the end only one thing counts in a commercial project. Does it look right? Then that's good enough 99% of the time.

"Does it look right?"

That's just it, in reality, I'm suggesting it does not.
...and with all the rendering trickery applied, it doesn't look like a photograph of a real thing, it looks like a rendering, cartoonish, it has no depth of rightness, just my humble opinion.

Fact: I can't sell that to my customers.
« Last Edit: January 08, 2019, 11:11:18 am by DetroitVinylRob »

Offline Niko Planke

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Re: How to achieve realistic led glow
« Reply #9 on: January 10, 2019, 01:53:19 am »
There is a simple and likely faster way to get a more realistic look without having to model the LEDs them selves.

By using IES lights instead you can control the light sources directionality. The LED manufacturer should be able to provide the ies information.
The problem here, compared to an area light source, is that point/ies light sources are infinitely small and therefore not directly visible. One option is to encapsulate the light sources in a Scattering medium.
The scattering medium will introduce a glow around the light source(both point and area light) and make point light sources visible, which is what we are going for here.

Overall i think a scattering medium will give the most realistic glow effect, while the already mentioned new bloom effect in image styles will give more direct control and the fastest results.

For the  Mouse example i would probably try:
* An Arealight (or an array IES lights if you do not like the "Tron look")
* Cloudy plastic with an almost white transmission color and low cloudiness to emulate the plastic cover above the leds
* A "thin" scattering medium with an almost white transmission color and comparably high Transparency distance to create the Glow around it.
      It will need a bit of fiddling but you will probably want to have a bright transmission color and a comparably high transparency distance. You can use a bright albedo color to controll the amount of glow.
      The Fog material in the library are a good starting point, i had to make the Transmission color brighter to make sure that the medium is only visible around bright light sources.
      The exact settings depend on you desired outcome and lighting set up.

An other challenge is that especially RGB leds on light strips tend to have separate light sources for the colors with a slight offset, this creates "fringes" of color on the edges of sharp shadows. But it figure it can usually be ignored without loosing realism.
For the sake of rendering speed that might be best handled in Post if the effect is desired.