[tom]

Yeah, Torolf did this test and it's quite beautiful! Thank you TOROLF!

[ignacio]

Tom I think there was a compartion with a real picture. Is it right? You have the real test??

Ignacio

[tom]

Yes, thank you Ignacio

This is a forced dispersion test I've done with beta before release.
I say "forced" because it uses a very low abbe to show the spectrum clearly.
On the top row, you're viewing the original visible spectrum. Bottom row parted into two, the lower part is the original rendering of the reflection screen and the upper part is blured in photoshop to match the result with the original spectrum. The question mark shows the color beyond violet means ultaviolet. I'm not sure if it should be there and it will be checked soon.

[Aldaryn]

This was a great test Tom, and its geat to have a correct spectrum.

Btw, I always get distinct bands of colors instead of a soft transition, when I do dispersion tests, is there a way to control how accurate the solution is? Or this is just a small bug right now, and I sholud always get a smooth spectrum solution in time?

[tom]

it's all about conditions aldaryn, let's see your tests and look what's going on.

[tom]

this i not bug because it's a "forced" test with an extreme abbe number.
as you see in Torolf's artistic output, the prism disperses it smoothly.

[Aldaryn]

Really simple, brigth bars behind sphere with abbe 2. So, yuo say the banding is only because of the extreme conditions? I've expected to get a smooth transition even in situations like this.
Anyway, I really like the new spectrum.

[Aldaryn]

I think none of them, its just an extreme situation, and this is how its now handled.
I doubt that you'll ever need a better specrum resolution in everyday rendering tasks.

Still, I would really love to render images like this (WinOSI)

[tom]

if you supply same conditions, may took long but it should render the same...
maybe torolf can setup the scene since he's good at winosi

[Aldaryn]

I've downloaded the winosi scene, and gave it a try, but even with an abbe value of 2 the spectrum was not wide eneugh, and some strange artifacts (brigt colorful dots) appared.
Im not really good at optics, so, someone with some free time, and knowledge might give it a try.

[Becco_UK]

This is a photo' I took one day in August, 2003. At the time it was to replicate a natural gradient in an image (that never was finished!).

Kept the photo' thinking it may come in useful another time and here we are in the era of Maxwell Render. - May be useful dispersion comparisons?

[Becco_UK]

lolec: The photo is one of several natural dispersion patterns I see every sunny morning in my living room. On the window panes are a few crystal ornaments, so as the morning sun hits them they create the sort of patterns you see.

This pattern, being cast on the floor, caught my eye so I simply placed some paper on the floor and took the photo'. A drawing would only show me crouching, holding a camera!

I took this because I wanted a natural gradient rather than something computer generated.

It may be worth keeping in mind that first the sunlight went through a single pane of glass before going through the crystal object - this may have affected the result - but some natural rainbow photo's I have suggest the gradient is correct.

A few more photo's would be needed to verify the above gradient.

Let's hope for some sun in the next day or so!