Has anyone a good explaination what this node does? I just can't wrap my head around it. How and when is it supposed to be used?
Can anyone link me to a throughout explaination?
Thanks a lot.
Gaussian Spectrum
Moderators: ChrisHekman, aoktar
Hi Dino,
Been looking into it myself, and I think in basic terms it's a way to give you colour based on realistic spectra.
Someone please correct me if I'm wrong here.
It's best described in images and a (very badly drawn) graph

So inputting those values (roughly) into the GS node (wavelength in μm not nm like the graph) and putting it in the Spec channel (Index = 1) gives you this:

Increasing the width value will widen the spectra included and eventually desaturate to white.
You can of course add variation to the wavelength to give you varying colours:

cheers
brasc
Been looking into it myself, and I think in basic terms it's a way to give you colour based on realistic spectra.
Someone please correct me if I'm wrong here.
It's best described in images and a (very badly drawn) graph


So inputting those values (roughly) into the GS node (wavelength in μm not nm like the graph) and putting it in the Spec channel (Index = 1) gives you this:

Increasing the width value will widen the spectra included and eventually desaturate to white.
You can of course add variation to the wavelength to give you varying colours:

cheers
brasc
Rig#1 Win 10 x64 | GTX 1080Ti | GTX 1080Ti | GTX 1080Ti | i7 7900K 4.7GHz | 64GB
Rig#2 Win 10 x64 | GTX 1080Ti | GTX 1080Ti | GTX 1080Ti | i7 3930K 4.4GHz | 32GB
Rig#3 Win 10 x64 | GTX 1070| GTX 1070| GTX 1070| i7 2600K 4.8GHz | 32GB
Rig#2 Win 10 x64 | GTX 1080Ti | GTX 1080Ti | GTX 1080Ti | i7 3930K 4.4GHz | 32GB
Rig#3 Win 10 x64 | GTX 1070| GTX 1070| GTX 1070| i7 2600K 4.8GHz | 32GB
Hi,
perfect explanation, brasco
In simple words we could consider it like another way to input colors. Since Octane converts the RGB colours to a spectrum, using this node, the color is not converted. It works in a similar way as the HSV space where the Hue is given by the Wavelength, the Saturation by the Width value (in the opposite direction, lower values will give more saturated colors), and finally the Value is given by the Power value. You can use it in any color input pin, for example in texture emission node gives much better results compared with a classic RGB node
ciao beppe
perfect explanation, brasco

In simple words we could consider it like another way to input colors. Since Octane converts the RGB colours to a spectrum, using this node, the color is not converted. It works in a similar way as the HSV space where the Hue is given by the Wavelength, the Saturation by the Width value (in the opposite direction, lower values will give more saturated colors), and finally the Value is given by the Power value. You can use it in any color input pin, for example in texture emission node gives much better results compared with a classic RGB node

ciao beppe
Hi, can you elaborate on this
"for example in texture emission node gives much better results compared with a classic RGB node"
what do you mean by better results? accurate color? faster render?
Thanks
Sandi
"for example in texture emission node gives much better results compared with a classic RGB node"
what do you mean by better results? accurate color? faster render?
Thanks
Sandi
Hi,
here are some explanations by roeland:
viewtopic.php?f=9&t=23669&hilit=gaussian
viewtopic.php?f=30&t=39041&p=177911&hil ... an#p177911
viewtopic.php?f=30&t=32201&p=139325&hil ... an#p139325
ciao beppe
here are some explanations by roeland:
viewtopic.php?f=9&t=23669&hilit=gaussian
viewtopic.php?f=30&t=39041&p=177911&hil ... an#p177911
viewtopic.php?f=30&t=32201&p=139325&hil ... an#p139325
ciao beppe
wow thanks beppe! using the gaussianspectrum for colored emission is wonderful solution. i will definitely remember it.bepeg4d wrote:Hi,
here are some explanations by roeland:
viewtopic.php?f=9&t=23669&hilit=gaussian
viewtopic.php?f=30&t=39041&p=177911&hil ... an#p177911
viewtopic.php?f=30&t=32201&p=139325&hil ... an#p139325
ciao beppe

4x 980ti EVGA | 5930k | Asus X99 E WS 3.1 | corsair 64GB RAM |SSD 500GB system + SSD 2TB working files + 6TB HDD storage WD |
Phanteks Enthoo Primo | 1600W EVGA T2 BLACK | It's the fastest 4x980ti build: http://goo.gl/hYp8e0
https://yambo.me
Phanteks Enthoo Primo | 1600W EVGA T2 BLACK | It's the fastest 4x980ti build: http://goo.gl/hYp8e0

https://yambo.me
Extremely helpful! Thanks!bepeg4d wrote:Hi,
here are some explanations by roeland:
viewtopic.php?f=9&t=23669&hilit=gaussian
viewtopic.php?f=30&t=39041&p=177911&hil ... an#p177911
viewtopic.php?f=30&t=32201&p=139325&hil ... an#p139325
ciao beppe
Thanks for the links!
- MildMustard
- Posts: 125
- Joined: Tue Jun 10, 2014 6:00 am
Anyone know how to find the width and power of the wavelength on a given metal, like Copper on http://refractiveindex.info/?shelf=main ... age=Rakic/ ?