Author Topic: Render atmosphere without god rays  (Read 2132 times)

Offline Darknight

  • Member
  • *
  • Posts: 67
  • Ever tried? Ever failed? Try Again. Fail better.
    • Personal Website
Render atmosphere without god rays
« on: May 27, 2014, 09:18:37 PM »
Hey guys,
I was wondering if there's a way to turn off the god rays feature. I dont want god rays since i will be making additive godrays added in post.
Thanks,
Mukul.
It's not who you are that matters, it's what you do.

Offline bobbystahr

  • Member
  • *
  • Posts: 9320
  • Turn, and face the Strange Ch Ch Changes...D Bowie
Re: Render atmosphere without god rays
« Reply #1 on: May 27, 2014, 10:28:35 PM »
Hey guys,
I was wondering if there's a way to turn off the god rays feature. I dont want god rays since i will be making additive godrays added in post.
Thanks,
Mukul.

Disable/unclick defer atmo/cloud and make sure Receive shadows from surface in the Atmosphere Tab is also unclicked
something borrowed,
something Blue.
Ring out the Old.
Bring in the New

bobbystahr

Offline Darknight

  • Member
  • *
  • Posts: 67
  • Ever tried? Ever failed? Try Again. Fail better.
    • Personal Website
Re: Render atmosphere without god rays
« Reply #2 on: May 28, 2014, 12:48:23 AM »
Hey guys,
I was wondering if there's a way to turn off the god rays feature. I dont want god rays since i will be making additive godrays added in post.
Thanks,
Mukul.

Disable/unclick defer atmo/cloud and make sure Receive shadows from surface in the Atmosphere Tab is also unclicked

Thanks. I turned off defer atmo/cloud in the render node but I couldn't locate the Receive shadows from surface anywhere. But already I can see a difference.
It's not who you are that matters, it's what you do.

Offline Tangled-Universe

  • Terrevangelist
  • *
  • Posts: 6101
    • CGScenery.com - Terragen Tutorials!
Re: Render atmosphere without god rays
« Reply #3 on: May 28, 2014, 06:12:05 PM »
Defer atmo/cloud has nothing to do with it I'm afraid.
Defer atmo/cloud means that TG will render it using the raytracer engine instead of the rasterizer engine (used for everything by default, except for objects).

God rays are essentially shadows in the atmosphere.

With that in mind then 2 entities can cast shadows into the atmosphere, terrain, clouds or both.

So if your terrain creates the shadows then indeed disable "receive shadows from surfaces" (default setting anyway).
If your clouds create the shadows then disabling "receive shadows from surfaces" won't help.

What you like to do then is to tell the renderer to render the clouds, but not the shadows generated by those clouds.

In TG your cloud node has a setting called "enable primary rays", this means that the renderer will render the clouds visible.
Below that you can find "enable secondary rays", which means that if a primary ray has "found" a cloud it will shoot rays from there which will calculate shadows, GI etc. of that particular part of the cloud.
It's probably not exactly how it works, but for me it kind of works to think of it like that.

So when we disable secondary rays in the clouds we should not have godrays anymore.
And that works.....howeeeeevvveerrrr...your clouds look totally different, because all the detail and shadows within the clouds themselves are also generated by secondary rays!

Offline Tangled-Universe

  • Terrevangelist
  • *
  • Posts: 6101
    • CGScenery.com - Terragen Tutorials!
Re: Render atmosphere without god rays
« Reply #4 on: May 28, 2014, 06:14:04 PM »
A kind of workaround is to use the 2D shadowmap function and set everything to 0 there.

You will notice that because of these settings the clouds will cast shadows all over your terrain, so be aware of that.

You can try increasing the resolution with steps of 10, but you will soon notice that godrays will re-appear.

Offline Darknight

  • Member
  • *
  • Posts: 67
  • Ever tried? Ever failed? Try Again. Fail better.
    • Personal Website
Re: Render atmosphere without god rays
« Reply #5 on: May 28, 2014, 10:23:36 PM »
A kind of workaround is to use the 2D shadowmap function and set everything to 0 there.

You will notice that because of these settings the clouds will cast shadows all over your terrain, so be aware of that.

You can try increasing the resolution with steps of 10, but you will soon notice that godrays will re-appear.
I toned down the haze by quite a bit and now there seems to be a lot less rays. Looks like this should work for me now. I just went by the science behind volumetrics...less particles in the atmosphere = less volume = less god rays! Thanks for the suggestions buddy! Here is the result.
It's not who you are that matters, it's what you do.

Offline bobbystahr

  • Member
  • *
  • Posts: 9320
  • Turn, and face the Strange Ch Ch Changes...D Bowie
Re: Render atmosphere without god rays
« Reply #6 on: May 29, 2014, 01:08:14 PM »
Thanks for your fine explanation TU...it explained a couple of things I was quite fuzzy on....
something borrowed,
something Blue.
Ring out the Old.
Bring in the New

bobbystahr

Offline Oshyan

  • Planetside Staff
  • *
  • Posts: 12366
  • Holy snagging ducks!
Re: Render atmosphere without god rays
« Reply #7 on: May 30, 2014, 03:44:07 AM »
Wow, that is a gorgeous cloudscape! T-U's explanation is pretty good in case you need to go that route, but it looks like you've got what you need.

- Oshyan

Offline Darknight

  • Member
  • *
  • Posts: 67
  • Ever tried? Ever failed? Try Again. Fail better.
    • Personal Website
Re: Render atmosphere without god rays
« Reply #8 on: June 02, 2014, 09:03:58 PM »
Wow, that is a gorgeous cloudscape! T-U's explanation is pretty good in case you need to go that route, but it looks like you've got what you need.

- Oshyan

Thanks man! :)
It's not who you are that matters, it's what you do.

Offline D.A. Bentley

  • Member
  • *
  • Posts: 231
    • D.A. Bentley
Re: Render atmosphere without god rays
« Reply #9 on: March 10, 2018, 11:26:30 PM »
Just what I was looking for!  Thanks!

Amazing clouds too Darknight.