Godrays experiments

Started by Rhalph, September 25, 2009, 02:18:13 PM

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Rhalph

Hello all!

I'm currently experimenting with creating good godrays. I will use this thread to post the results: test renders, WIPs but also final renders.

Let me explain: 9 years ago, when I first began to create 3D landscapes, my ultimate dream was to create a misty forest with godrays, like this one from Digital Blasphemy (this picture was made in 2001!!)
But I had a slow computer (pentium 233Mhz), and I didn't know any software able to create it (or I didn't have the knowledge - I was 15).
During these years I tried Bryce, Vue, World Builder, ... but my computer was still terribly slow, I didn't have the patience to learn to use them enough to create my dream picture. The only software that was fast enough for my computer to create landscapes was Terragen 1, and believe me, I made a lot of renders with rays (first rays in late 2001)... But no vegetation :(

Annnnd... Came Terragen 2. Which had the Power. But that was not the case of my computer (a Pentium 3 1.7Ghz), so my alpha tester years were not productive at all -_-

Now I am no more a student, and I have a work. It allowed me to buy a new computer four months ago and to be back to TG2, with the knowledge level of an almost-newbie.
But I still wasn't able to create those damn rays :P
I knew from the forums that I needed a low cloud to use it as fog, with raytraced shadows in it, but I couldn't manage to make object shadows to form visible rays in this fog.

A few days ago I saw the Moonmagic renders from cyphyr, and asked him some advices... With his help (thanks again cyphyr), and during the frenzy trance caused by an insomnia and a dicease, I managed to create my first f***ing forest god rays \o/

And a few tests later, here is the first test render that I want to show. The sun is a bit like disco lasers, but hey... It's only the beginning :)

cyphyr

Excellent :)
You got it
It doesn't have the subtility of the Digital Blasphemy inspiration but this is an excellent start, Texture and rough up the ground, work on maybe some translucency on the pine needles (not much if at all), and experiment on "texturing" your fog.
Did you use soft shadows and what were the final settings, atmo and cloud quality, render detail etc ?
:)
Richard
www.richardfraservfx.com
https://www.facebook.com/RichardFraserVFX/
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Ryzen 9 5950X OC@4Ghz, 64Gb (TG4 benchmark 4:13)

Rhalph

Thanks :)
No soft shadows, strength 10 for the sun (which is very orange), almost no atmosphere...
1/1 GI, 9 AA, Detail 1, 1680x1050 for the original render (I didn't note the render time -_-)
Oh, and quality 4 for the clouds (58 samples only). I wonder if increasing the atmo quality would have removed the graininess... Because atmo is almost not present in the scene, I kept the default 16 samples.

I'm planning to use another type of trees... One with longer trunks, but I'm afraid to copy the Digital Blasphemy pic, so I don't know. Anyway, longer trunks would mean bigger rays and would remove this "disco" effect. As for the decoration of the ground, I don't know ^^
Maybe some grass, but I never planned on bringing much detail on it. After all these years of hoping to make this type of pictures, I always thought about the trees and the rays, never about the ground :D

cyphyr

No way you'd be copying the Digital Blasphemy pic, well you could but what would be the point? Be inspired by an image you love and create something in homage to it. I'm sure what ever you create will have more of "Rhalph" in it than "Digital Blasphemy".
Increasing the atmo quality may help with the grain as would raising it in your cloud but really this is one of the least grainy "God rays" pictures I've seen in a long time.
:)
Richard
www.richardfraservfx.com
https://www.facebook.com/RichardFraserVFX/
/|\

Ryzen 9 5950X OC@4Ghz, 64Gb (TG4 benchmark 4:13)

Tangled-Universe

Cool rays, very well done!
I know a nice forest with grasses and bushes etc. where these rays would look great ;)

Cheers,
Martin


pfrancke

As the image from years ago inspired, so does what you do!  It is looking good and I'd like very much to see how it continues to develop.  I fear these things are always a matter of give and take, seems that you can't have everything.  So you have to choose where to focus.  And the discussion about the settings is very interesting.  I never would have guessed about the low atmosphere for instance.

Seth

testing on some forest from mine, i had less "laser results" with deeper atmosphere Rhalph.
but, of course, it is harder to have good contrast with deep atmo...
As I don't know your settings, I don't know if it will do something good to you.


Henry Blewer

I get great godrays from setting the atmosphere samples to 128. The key is to get the sun behind an object or cloud. Do a small render at 0.5 quality, 320 x 200. Look where the halo of the sun is. Move the sun so it just clips the edge of the clouds/objects, you'll want the halo partially obscured. Now render at the same settings. When the 'look' is what you had in mind, do the full render. For the godrays to really 'shine' the render quality should be 0.9 or 0.95. I never go for more than that.

http://farm3.static.flickr.com/2669/3867244825_8c8a7d7047_o.jpg

You can see the light rays spilling from around the clouds in this pic.
http://flickr.com/photos/njeneb/
Forget Tuesday; It's just Monday spelled with a T

Seth

Quote from: njeneb on September 26, 2009, 02:09:00 PM
I get great godrays from setting the atmosphere samples to 128. The key is to get the sun behind an object or cloud.



this is not the same technique used by Rhalph. And you can try to put your sun behind an object, i am not sure you'll get rays.
you can have good godrays with low atmo sample but using clouds as fog...

Henry Blewer

My way works without fog and I usually get them by accident.
http://flickr.com/photos/njeneb/
Forget Tuesday; It's just Monday spelled with a T

Seth

errr... can you show me your rays caused by objects using your way ?

Henry Blewer

#12
I'll see if I can find the tgd. One I did recently with the free edition is here
http://farm4.static.flickr.com/3467/3765638110_6d3742e591_o.jpg
and here
http://farm3.static.flickr.com/2552/3797705323_c270fc30f7_o.jpg

Come to think of it, I can't think of any I did using objects, except one through some trees. It was some time ago. These are both sky effects. If I can find one I'll post the link.

Edit: Just looked quickly through my Flickr stuff. Not one through objects. This will be the next experiment! Ah, inspiration...
http://flickr.com/photos/njeneb/
Forget Tuesday; It's just Monday spelled with a T

Seth

that's what I said, no rays with object without clouds :)
I may be wrong though, so if anybody has another way to do it...

cyphyr

Rays are cast in two ways, from clouds and onto clouds. If they're cast from clouds you don't need raytrace shadows enabled. If they're cast onto clouds (or clouds pretending to be fog as in our case) then you'll need ray trace shadows enabled.
:)
Richard
www.richardfraservfx.com
https://www.facebook.com/RichardFraserVFX/
/|\

Ryzen 9 5950X OC@4Ghz, 64Gb (TG4 benchmark 4:13)