Passed it! (Rainbow experiments)

[Mahnmut]

Grass by DandelO, Trees by Xfrog.

[inkydigit]

omg double rainbow!!!!!
what does it mean?....I mean how did you do it?
looks great

[domdib]

Rainbow looks impressive. The grass shader isn't really designed for close-ups though, so either lifting the viewpoint some, or distance shading in a grass object population would give it a more authentic look.

[mesocyclone]

Amazing!!
Though it's a little small, rainbows have a 42º radius for the primary bow

[Dune]

If this is procedural, it's really a great achievement. There is some banding; can you get that any smoother? Care to enlighten us about your method?

[Mahnmut]

Thanks for all your comments.
@ Inkydigit :
It means that I passed not only that storm but also the written part of my final exams
-and how I did it I will tell you later.

@Dombib:
Actually I didn´t care for the terrain that much in this first version, just wanted to show off my rainbow

@mesocyclone:
of course you are right about the angle, the second bow is also to close, but I wanted to have it all in the image.

@Dune:
Yes, the banding is a problem. unfortunately my preview-cropregion was in the righthand part where it is least obvious.
I am sure it can be smoothened somehow, but that will need some finetuning.
What I really don´t understand is why the violet part appears so low, it even looks unconcentric, what shouldn´t be possible.
Could be foreshortening, but I still don´t understand it.
I will share my method and a clipfile, but my ego would like some more comments before I do so.

Best regards,
Jan

[schmeerlap]

Wow! How did you create that rainbow?

(copy, paste, and post the above text to fast track solution) 

John

[TheBlackHole]

[dandelO]

Ah ha! I think I see what you've done here, very good! More altitude in the colours(from a single radius control, I would think ) and push it way back in the distance and you're onto a real winner!

Congrat's on the pass. Twice!

*Edit: TBH, the colours in Jan's rainbow are reversed in the secondary arc. Unless I've missed a previous version edit.

[Hetzen]

I'm not sure how you've done this outside post work. Intrigued.

[Mahnmut]

Thanks Schmeerlap,
your kind words show me that you would like to see my clipfile.

Blackhole, look again, there is only one version of this image yet and the colours are in order. Although I have learned since that secondary spectra  differ in some other ways, but anyone can adjust his rainbow as he likes, so I won´t change much now.

dandelO, Thanks for the congrats.
I am not surprised that you get the clue, maybe I would have tried it with a bunch of spherical distance shaders if I had not seen your metaclouds, that would have been a pain.
So, I used one planets atmosphere with 14 cloud layers.

Funny thing is, I thought I would have to use the intersection of this sphere with two linear distance shaders to cut a slice out of it, but I realized that those shaders weren´t plugged in only after it looked like it does.
There is only a diffuse shimmering of colours that shows it is a sphere, not an arc, and I think the sphere-shape helps blurring the banding, at least where the density is high enough.
I am working on a second version now that I will post tommorow together with a clip file.
But I still dont understand why the violet arc seems to be flatter than the others.
Maybe it is foreshortening and will be solved if the whole thing is bigger and further away like dandelo suggested.
Thanks for your interest,
Best Regards,
Jan

[dandelO]

I had an idea to restrict an atmosphere, like I did with the Saturn ring image called 'the grudge', I posted a while ago, but I can't find a way to constrain an atmosphere node in that way. I don't think it's possible.

I can make a perfect spectrum with one atmosphere node BUT it can't be constrained to a ring conventionally(ignore the red/yellow object in the centre, when it isn't rendered, the colours are correct).


Alas! I didn't go as far as 14 cloud layers! Cool!

[Mahnmut]

It would be seven cloud layers for a single rainbow, and I wonder if your method could work together with mine.
As I said, these spherical cloudlayers arent restricted at all, I wanted to but didn´t by accident.
They are only that thin that they only show up much where you look tangentially to the sphere.

Maybe that explains, what is flubbergasting me at the moment.
It seems that how ever I move the rainbow-planet up and down, (even to the sides) the rainbow stays the same. That makes no sense, there must be a mistake.
For one moment I thought it may really move with the suns counterpoint, but that doesn´t work either.
Test renders are slow on my computer, I think I will just post the TGD in some minutes.
Correction, it seems to be broken.
Let me fiddle with it some more, her comes the beta version of the clipfile, it works if simply thrown into the landscape, but there are some things that I still don´t understand about it. Have fun! I think I will make a better version soon, but maybe it´s just like with the starfields, once the idea is there evolution starts.
Best regards, Jan
I don´t understand it!

[dandelO]

Maybe the same thing as in this thread is like what you are experiencing with the rainbow not being able to be moved... http://forums.planetside.co.uk/index.php?topic=10667.msg109805#msg109805

[cbest]

Grass by DandelO, Trees by Xfrog.

What was the grass made on? Blender?