[hdesbois]

I'll try to post a tutorial some day.
HD

[hdesbois]

rendering: emerald, emerald.ior
data extrapolated from : http://www.britannica.com/eb/art-1059




data:

1 1.57 3.23 32
1.578000000 0.000000000
1.580000000 0.000000000
1.583000000 0.000000000
1.585000000 0.020820000
1.586000000 0.022120000
1.586000000 0.039300000
1.585000000 0.050550000
1.583000000 0.055050000
1.580000000 0.056660000
1.578000000 0.048930000
1.576000000 0.027830000
1.574000000 0.005643000
1.574000000 0.000550900
1.575000000 0.000000000
1.577000000 0.000000000
1.579000000 0.000000000
1.581000000 0.001056000
1.584000000 0.002928000
1.586000000 0.009986000
1.587000000 0.022450000
1.587000000 0.039090000
1.587000000 0.051210000
1.586000000 0.051820000
1.585000000 0.048520000
1.583000000 0.043910000
1.582000000 0.039810000
1.582000000 0.035780000
1.582000000 0.032500000
1.583000000 0.029410000
1.584000000 0.027090000
1.586000000 0.026080000
1.580000000 0.025270000
1.580000000 0.025270000

S.L.: 21
Render Cost: MEDIUM
Remarks: N/A

[Thomas An.]

nice find hdesbois. It would be great to have an editable graph like that within Maxwell!

I am afraid adjusting directly n,k curves would not be usefull at all. It is an entirely abstract process that the mind has no prior references to build any intuition for it.

Both the n and the k curves control color (both interact towards reflectance). ... and at the same time control absorbance / attenuation

... this would be good only as an academic curiocity, but that is about it (IMHO).

[Tyrone Marshall]

Stellar work Hdesbois! I will be preparing a thumbnail of the new IOR files you have recovered. This set will be named in your honor! Keep them coming!

I especially love the "Blood Red Ruby"!

[hdesbois]

Thanks!
medium blue sapphire.
Data from:
http://minerals.gps.caltech.edu/FILES/Visible/index.htm




data:

4 352.2 802.2 90
1.799000000000 0.000000365
1.799000000000 0.000000311
1.799000000000 0.000000264
1.793000000000 0.000000254
1.791000000000 0.000000258
1.791000000000 0.000000340
1.791000000000 0.000000330
1.794000000000 0.000000340
1.796000000000 0.000000280
1.799000000000 0.000000199
1.797000000000 0.000000153
1.793000000000 0.000000136
1.788000000000 0.000000130
1.784000000000 0.000000129
1.782000000000 0.000000131
1.783000000000 0.000000136
1.786000000000 0.000000146
1.789000000000 0.000000164
1.791000000000 0.000000192
1.785000000000 0.000000223
1.782000000000 0.000000261
1.780000000000 0.000000236
1.777000000000 0.000000221
1.775000000000 0.000000200
1.773000000000 0.000000197
1.771000000000 0.000000184
1.770000000000 0.000000182
1.768000000000 0.000000187
1.767000000000 0.000000197
1.766000000000 0.000000209
1.765000000000 0.000000223
1.764000000000 0.000000239
1.763000000000 0.000000255
1.762000000000 0.000000271
1.762000000000 0.000000288
1.761000000000 0.000000305
1.761000000000 0.000000321
1.761000000000 0.000000337
1.762000000000 0.000000353
1.762000000000 0.000000367
1.763000000000 0.000000381
1.764000000000 0.000000394
1.765000000000 0.000000405
1.765000000000 0.000000415
1.766000000000 0.000000424
1.766000000000 0.000000432
1.767000000000 0.000000439
1.768000000000 0.000000444
1.768000000000 0.000000449
1.769000000000 0.000000454
1.769000000000 0.000000457
1.769000000000 0.000000461
1.768000000000 0.000000465
1.768000000000 0.000000470
1.768000000000 0.000000474
1.768000000000 0.000000479
1.767000000000 0.000000484
1.767000000000 0.000000491
1.767000000000 0.000000497
1.767000000000 0.000000505
1.767000000000 0.000000513
1.767000000000 0.000000522
1.767000000000 0.000000531
1.766000000000 0.000000542
1.766000000000 0.000000553
1.766000000000 0.000000565
1.766000000000 0.000000578
1.765000000000 0.000000591
1.765000000000 0.000000606
1.765000000000 0.000000620
1.764000000000 0.000000637
1.763000000000 0.000000653
1.763000000000 0.000000671
1.762000000000 0.000000691
1.762000000000 0.000000710
1.761000000000 0.000000731
1.761000000000 0.000000753
1.760000000000 0.000000774
1.760000000000 0.000000799
1.760000000000 0.000000823
1.759000000000 0.000000848
1.759000000000 0.000000876
1.758000000000 0.000000902
1.758000000000 0.000000929
1.757000000000 0.000000959
1.757000000000 0.000000988
1.756000000000 0.000001014
1.756000000000 0.000001045
1.755000000000 0.000001075
1.755000000000 0.000001101
1.754000000000 0.000001131

S.L.: 21
Render cost: MEDIUM
Remarks: k values calculated from absorbance values to the best of my knowledge (that's not saying much). N values conjectural. Some anormalous dispersion added near absorption maxima. I think getting the exact refraction at all frequencies is not crititcal with coloured dielectrics, since many frequencies are absorbed and dispersion is not likely to show anyway. Unlike any other transparent ior material so far, this one has no "0 absorption band". That implies that even blue light is attenuated, so it should be checked at various scales. Ruby and emerald materials should not be scale dependant.

[glebe digital]

These are great Henri, keep 'em coming.

[hdesbois]

amethyst.ior

data from same source as above.



data:

4 301 791 49
1.555 0.000000052842
1.554 0.000000004472
1.554 0.000000123441
1.553 0.000000341618
1.553 0.000000781668
1.554 0.00000135039
1.554 0.00000176503
1.555 0.000001818371
1.556 0.000001623866
1.556 0.000001420629
1.554 0.000001273005
1.554 0.000001124059
1.553 0.0000009326
1.552 0.000000742694
1.551 0.000000637823
1.551 0.000000644304
1.55 0.000000736976
1.55 0.000000885941
1.549 0.000001077424
1.549 0.000001286445
1.549 0.000001495769
1.548 0.000001696899
1.548 0.000001862037
1.548 0.000001993023
1.549 0.000002074785
1.549 0.000002119814
1.55 0.000002110447
1.551 0.000002066551
1.551 0.000001981828
1.551 0.000001889659
1.549 0.000001782748
1.548 0.000001672778
1.547 0.000001577174
1.546 0.000001479307
1.546 0.000001386951
1.545 0.000001297993
1.545 0.000001218053
1.544 0.000001169096
1.544 0.00000111906
1.543 0.000001064441
1.543 0.000001054824
1.543 0.000001050929
1.542 0.000001029809
1.542 0.000001019892
1.542 0.000001062702
1.541 0.000001085989
1.541 0.000001113502
1.541 0.000001151557
1.541 0.000001210209
1.541 0.000001242389

S.L.: 20
Render cost: MEDIUM
Remarks: absorption has been scaled down after conversion to match the scale of the test scene. Unscaled version is here :

4 301 791 49
1.555 0.00000320568
1.554 0.00000310894
1.554 0.00000334688
1.553 0.00000378324
1.553 0.00000466334
1.554 0.00000580078
1.554 0.00000663006
1.555 0.00000673674
1.556 0.00000634773
1.556 0.00000594126
1.554 0.00000564601
1.554 0.00000534812
1.553 0.0000049652
1.552 0.00000458539
1.551 0.00000437565
1.551 0.00000438861
1.55 0.00000457395
1.55 0.00000487188
1.549 0.00000525485
1.549 0.00000567289
1.549 0.00000609154
1.548 0.0000064938
1.548 0.00000682407
1.548 0.00000708605
1.549 0.00000724957
1.549 0.00000733963
1.55 0.00000732089
1.551 0.0000072331
1.551 0.00000706366
1.551 0.00000687932
1.549 0.0000066655
1.548 0.00000644556
1.547 0.00000625435
1.546 0.00000605861
1.546 0.0000058739
1.545 0.00000569599
1.545 0.00000553611
1.544 0.00000543819
1.544 0.00000533812
1.543 0.00000522888
1.543 0.00000520965
1.543 0.00000520186
1.542 0.00000515962
1.542 0.00000513978
1.542 0.0000052254
1.541 0.00000527198
1.541 0.000005327
1.541 0.00000540311
1.541 0.00000552042
1.541 0.00000558478

It renders black with the test scene, but it coulb be interesting to try a jewel scene with it, since the preview looks ok. As the absorption is not the same for all wavelengths, the colour may actually change with thickness of the object just like the color of the light change with water depth. Thin parts are more pinkish, thich parts almos black.

[glebe digital]

Thanks!
medium blue sapphire.
Data from:
http://minerals.gps.caltech.edu/FILES/Visible/index.htm

Some very useful minerals in that site, but how to use the data from that format? Seems to be different to Sopra Any hints would be great........there's a calcite in there I reckon would be a great substitute for travertine/limestones etc.

[hdesbois]

hi,
The data are just absorbance values. You can approximate extinction coefficient by multiplying by wavelength and dividing the result by one billion. Then you have to tweak your k value by trial and error. Or you can try using formulas to get it accurate directly (divide by sample thickness, multiply by ln10, divide by 4Pi, multiply by wavelength), but you may still end with strange results hat will need tweaking, especialy (i don't know why) when the sample thickness is low. Maybe this is not the right formula. I strongly recommand that you crop/interpolate the dataset prior doing anything else. Then you still have to figurate the n part from another source, but as I explained earlier, this is not as critical as for a colorless material.
Concerning calcite, what is on the site are cristals of different tints, and I don't think they could help for limestone etc. Complex ior are useful for metals and transparent materials. The rest can be done much more efficiently using standard material system.

HD

[hdesbois]

yellow beryl. ior




data from same source as above.

Data:

4 380 725 69
1.581 0.00000658236
1.58 0.00000606298
1.579 0.00000560118
1.579 0.00000512394
1.578 0.0000046296
1.577 0.00000422091
1.577 0.00000380398
1.576 0.00000346525
1.575 0.00000311472
1.575 0.0000027591
1.574 0.00000247078
1.573 0.00000219849
1.573 0.00000199672
1.572 0.00000181204
1.572 0.0000016434
1.571 0.00000152061
1.57 0.00000140944
1.57 0.00000131316
1.569 0.00000123798
1.568 0.00000116945
1.568 0.0000011088
1.567 0.00000106312
1.567 0.00000102704
1.566 0.000000986931
1.566 0.0000009436
1.565 0.000000900112
1.564 0.000000858228
1.563 0.000000816893
1.563 0.000000775736
1.562 0.000000735315
1.562 0.00000070013
1.561 0.000000664577
1.561 0.000000605556
1.56 0.000000591325
1.559 0.00000058069
1.559 0.000000546453
1.558 0.000000512288
1.557 0.000000479798
1.557 0.000000444144
1.556 0.00000042113
1.556 0.000000413772
1.555 0.00000041184
1.554 0.000000415478
1.554 0.000000419951
1.553 0.00000042372
1.553 0.000000411037
1.552 0.000000403942
1.552 0.000000402825
1.551 0.000000415152
1.551 0.000000436375
1.55 0.000000470232
1.55 0.000000518033
1.549 0.000000576
1.549 0.000000643452
1.548 0.00000071864
1.548 0.000000808401
1.547 0.000000922812
1.546 0.000001054557
1.546 0.000001199434
1.546 0.0000013608
1.546 0.00000154496
1.546 0.00000176045
1.546 0.00000201894
1.547 0.00000231157
1.547 0.0000026432
1.548 0.00000302727
1.549 0.00000346906
1.549 0.00000395538
1.551 0.00000446256
1.552 0.0000049851

S.L.: 20
Render Cost: MEDIUM
Remarks: scale sensitive material.

[hdesbois]

aquamarine.ior




Data from the same source as above.

Data:

4 380 725 69
1.58 0.000000088217
1.58 0.000000061831
1.58 0.000000051812
1.58 0.000000048901
1.581 0.00000004542
1.581 0.000000043477
1.581 0.000000048073
1.581 0.000000052664
1.581 0.000000065079
1.581 0.000000083576
1.581 0.000000075895
1.581 0.000000054506
1.581 0.00000004367
1.58 0.000000038737
1.579 0.000000037193
1.578 0.000000037174
1.576 0.000000038709
1.575 0.000000041594
1.574 0.000000041736
1.573 0.000000044864
1.572 0.000000047688
1.571 0.000000050949
1.569 0.000000053582
1.568 0.000000057791
1.567 0.00000006175
1.566 0.000000064539
1.565 0.000000066785
1.563 0.000000072512
1.562 0.00000007826
1.561 0.000000079879
1.56 0.000000084005
1.559 0.000000089051
1.558 0.000000094068
1.557 0.000000097392
1.555 0.000000102438
1.554 0.000000108253
1.553 0.000000113036
1.552 0.000000119498
1.551 0.000000124089
1.55 0.000000129979
1.549 0.000000134299
1.548 0.00000014002
1.547 0.000000146645
1.546 0.000000151636
1.545 0.00000016095
1.544 0.000000166617
1.544 0.000000177022
1.543 0.000000185884
1.542 0.000000197625
1.542 0.000000210938
1.541 0.000000226076
1.542 0.000000240348
1.542 0.000000255968
1.543 0.000000274706
1.545 0.00000030069
1.546 0.000000327828
1.548 0.00000036168
1.55 0.000000395675
1.552 0.00000044153
1.554 0.000000490725
1.555 0.00000053856
1.558 0.000000607253
1.56 0.000000676545
1.562 0.00000076172
1.564 0.0000008568
1.566 0.000000966555
1.568 0.00000109411
1.57 0.000001220505
1.572 0.0000013698
1.574 0.000001527213

S.L.: 2O
Render cost: MEDIUM
Remarks: scale sensitive material.

[Tyrone Marshall]

Thanks a million Hdesbois!

Your collection has a home here:

ref: http://www.maxwellrender.com/forum/view ... 406#157406

[hdesbois]

thanks,
more are coming, and, hopefuly, a tutorial. Some materials are already available for downloading in goodies section. If some people want to help with rendering, it would be great: weather is now very hot here, and I have some overheating problems with my rendering box. I suggest rendering first orange garnet and new emerald. New ruby might have some scale issues with current scene but should work fine with gemstone sized objects. I'd like to release some colored glasses with matching refraction allowing material mixing. Stay tuned!
HD

[hdesbois]

orange garnet




Data from same source as above.

Data:
4 430.5 720.5 59
1.827 0.000003071187
1.828 0.000002687471
1.829 0.000002066826
1.829 0.000001593108
1.827 0.000001435293
1.825 0.000001464888
1.823 0.000001554188
1.821 0.000001523582
1.819 0.000001443965
1.818 0.000001486413
1.816 0.000001588533
1.813 0.000001609433
1.812 0.0000014715
1.81 0.000001338445
1.808 0.00000126126
1.806 0.000001242468
1.804 0.000001239596
1.802 0.000001264882
1.801 0.000001299324
1.799 0.00000132694
1.798 0.000001328584
1.797 0.000001305281
1.797 0.000001248879
1.798 0.000001172389
1.798 0.000001101881
1.798 0.000001047229
1.799 0.000001004024
1.8 0.000000975657
1.8 0.000000937389
1.801 0.000000911419
1.801 0.000000889732
1.801 0.000000881763
1.802 0.000000870869
1.802 0.000000868775
1.801 0.000000871205
1.799 0.000000856116
1.798 0.000000830768
1.796 0.000000814676
1.795 0.000000801748
1.793 0.000000793009
1.791 0.000000783081
1.79 0.000000757643
1.788 0.000000747656
1.787 0.000000743035
1.785 0.000000738057
1.784 0.000000741764
1.783 0.000000748809
1.781 0.000000749286
1.78 0.000000756324
1.779 0.000000748792
1.778 0.000000741881
1.776 0.000000742397
1.775 0.000000734761
1.774 0.000000734031
1.773 0.000000743301
1.772 0.000000744585
1.771 0.000000737286
1.77 0.000000740543
1.769 0.000000742259
1.768 0.000000745451


S.L.: 19
render costs: LOW (would have been MEDIUM with 1.0)
Remarks: scale sensitive material

[hdesbois]

ural emerald



data from same source as above.

Data:

4 380 725 69
1.586 0.0000033497
1.586 0.0000033649
1.585 0.000003442725
1.584 0.000003604375
1.583 0.000003825
1.584 0.000004063163
1.584 0.0000042968
1.584 0.000004466438
1.585 0.00000452235
1.585 0.000004450813
1.585 0.000004270975
1.585 0.000003926963
1.585 0.0000035772
1.584 0.00000326185
1.583 0.000002932875
1.582 0.000002586675
1.581 0.00000226895
1.58 0.000001983225
1.579 0.000001747225
1.578 0.0000015105
1.577 0.0000013236
1.576 0.000001164243
1.574 0.000001036105
1.573 0.000000957454
1.572 0.00000091625
1.571 0.000000895113
1.57 0.000000930878
1.569 0.000000997813
1.568 0.000001079
1.567 0.000001195688
1.566 0.000001316918
1.565 0.000001472588
1.564 0.0000016794
1.563 0.000001878888
1.562 0.000002127125
1.561 0.000002383725
1.56 0.0000027006
1.559 0.000003008625
1.558 0.0000033345
1.558 0.0000036225
1.558 0.00000393675
1.559 0.000004214925
1.56 0.000004532675
1.561 0.00000489685
1.562 0.0000053385
1.563 0.000005703638
1.564 0.000006116775
1.565 0.000006578963
1.566 0.00000700445
1.567 0.000007376563
1.568 0.000007690725
1.569 0.000007673975
1.57 0.0000080064
1.571 0.000008459175
1.572 0.000008568625
1.574 0.000007930413
1.575 0.0000077253
1.576 0.000007624225
1.577 0.000006815575
1.578 0.000005988938
1.579 0.0000056984
1.58 0.000007396288
1.581 0.00000564075
1.582 0.000004807663
1.582 0.00000424025
1.578 0.000003826388
1.575 0.0000035216
1.57 0.000003290788
1.566 0.0000031338
1.562 0.000003039563


S.L.: 19
Render cost: LOW (1.1)
Remarks: scale-sensitive material