Peak and Regular Tabulated Spectra

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Whaat
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Peak and Regular Tabulated Spectra

Post by Whaat » Wed Jun 03, 2009 9:22 am

Do any of the other exporters implement Peak and regular tabulated spectra?

@ benn/Ono: Is this going to be a required feature in the exporters? If so, how do you suggest we implement them in a user-friendly way? (not easy BTW)

IMO, probably less than 10% of Indigo users even know what this stuff is and probably less than 5% of those users will ever use these features. Should we add additional complexity by supporting these features and thus, alienate other users for the sake of this small percentage of users :?:

Hardcore users who want to render using the most accurate spectral data can always hand-edit the XML files. :wink: Right Wytraven?

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fused
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Re: Peak and Regular Tabulated Spectra

Post by fused » Wed Jun 03, 2009 9:32 am

Cindigo does, but only at a few distinct places (tabulated only in medium and peak only in emission).

I dont think it should be a required feature, but its definitely nice to have.

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Whaat
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Re: Peak and Regular Tabulated Spectra

Post by Whaat » Wed Jun 03, 2009 10:14 am

fused wrote:Cindigo does, but only at a few distinct places (tabulated only in medium and peak only in emission).

I dont think it should be a required feature, but its definitely nice to have.
See, the problem occurs when a user wants to share a material that was created using these features and not every exporters supports it. Right now, SkIndigo can pretty much load any IGM material (load not link) except for ones that contain these types of spectra. When I load the IGM, I do a pre-process check to see if they contain any of these spectrum elements. If they do, I give a warning message that this material cannot be loaded by SkIndigo and must be LINKED instead. I don't mind keeping it this way, but benn and Ono need to decide how they want us to handle these situations.

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Re: Peak and Regular Tabulated Spectra

Post by fused » Wed Jun 03, 2009 10:40 am

Im doing pretty much the same in cindigo, just a small difference: the material loads in any case. warnings are just for info.

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Re: Peak and Regular Tabulated Spectra

Post by benn » Wed Jun 03, 2009 11:38 am

I've been working on my pimped out material editor with preview, so I'd recommend far-out settings like tabulated and peak need not be done by the exporters.

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Re: Peak and Regular Tabulated Spectra

Post by benn » Wed Jun 03, 2009 11:39 am

Sample UI attached...
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Picture 2.png
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Polinalkrimizei
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Re: Peak and Regular Tabulated Spectra

Post by Polinalkrimizei » Thu Jun 04, 2009 8:02 am

WOw benn...! :shock:

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Re: Peak and Regular Tabulated Spectra

Post by PureSpider » Thu Jun 04, 2009 8:20 am

What's that graph for?

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Whaat
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Re: Peak and Regular Tabulated Spectra

Post by Whaat » Fri Jun 05, 2009 1:45 am

Looking good, benn! What sort of workflow do you have in mind for the material editor? I think the smoothest workflow would be something like this:
1) Create Materials in Material Editor
2) Save Materials as IGM
3) Load or Link the materials using an Exporter (Linking probably makes the most sense so you don't have to keep reloading the IGM into the exporter if you make more changes with the material editor)
4) Export and Render
5) Tweak materials in Material Editor and resave as IGM
6) Export and render (No need to reload if materials are linked)

Are you thinking of a similar workflow?

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WytRaven
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Re: Peak and Regular Tabulated Spectra

Post by WytRaven » Fri Jun 05, 2009 4:51 am

Whaat wrote:Right Wytraven?
Huh? What'd I do :lol:
:idea: "A foolish consistency is the hobgoblin of little minds..." - Emerson 1841

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WytRaven
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Re: Peak and Regular Tabulated Spectra

Post by WytRaven » Fri Jun 05, 2009 4:53 am

BTW that mock up is looking promissing Ben :)
:idea: "A foolish consistency is the hobgoblin of little minds..." - Emerson 1841

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Re: Peak and Regular Tabulated Spectra

Post by benn » Fri Jun 05, 2009 2:37 pm

Whaat - that's exactly what I had in mind. Either load the material from your local machine, or save the material to the material database and load it from there directly.

The graph is of a spectrum of wavelength versus absorption. I couldn't understand wth was going on with the various spectral quantities - but the spectral graph makes it way more obvious. :)

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Re: Peak and Regular Tabulated Spectra

Post by WytRaven » Fri Jun 05, 2009 4:15 pm

benn wrote:The graph is of a spectrum of wavelength versus absorption. I couldn't understand wth was going on with the various spectral quantities - but the spectral graph makes it way more obvious. :)
Well in that case you will need a second graph somewhere to show a graph of wavelength versus ior calculated via cauchy.

Now what would really rock is if you could interact with the graphs to visually manipulate the values with the graph updating in real time :)

So for for cauchy you would have a Cauchy A slider/text box (which equates to the ior parameter in indigo material spec) and a Cauchy B slider/text box and then update the graph to show the ior v wavelength curve as the parameters are changed.

For absorption your could do the same thing sort of thing but it would be best if you could drag points on the graph around (a basic spline editor would be best) and then calculate the absorption values through spline interpolation at say 10nm intervals between 350nm and 780nm.

I visually built the absorption table for my diamond material by creating a table in excel for the wavelengths mentioned above, graphed it and then manipulated the values to match the graph against a picture of a real measured graph I found online.

For a lot of info (misinfo?) on the cauchy and tabulated absorption stuff you can take a look at this thread http://www.indigorenderer.com/forum/vie ... f=3&t=2708


...or you could just put it all in the "too hard basket" ;)
:idea: "A foolish consistency is the hobgoblin of little minds..." - Emerson 1841

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Re: Peak and Regular Tabulated Spectra

Post by PureSpider » Sat Jun 06, 2009 12:21 am

WytRaven wrote:...or you could just put it all in the "too hard basket" ;)
...or introduce "WytMode" :lol:

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Re: Peak and Regular Tabulated Spectra

Post by pixie » Sat Jun 06, 2009 1:16 am

PureSpider wrote:...or introduce "WytMode" :lol:
:lol: so true! It's such a pitty that those thread can't be find anymore by search... Benn, please fix this issue.

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