Greetings! This is my first post!
I am new to the whole terragen 2 program so bare with me please :)
I have been giving the assignment to make a skybox. Now i have these weird black rays, looks like ray trace, or shadows on this grey piece of Haze ( I presume).
(http://img140.imageshack.us/img140/7506/screenhunter01nov241027.jpg)
Thanks!
I hope you can see the black line in the center. I need to get rid of that and those black rays on the haze
Try adding a fractal terrain in the Terrain Tab. Go to the Displacement Tab of the fractal terrain and reduce the displacement amplitude to about 100. Try the render again.
You can also increase the haze in the atmosphere. I noticed the light rays are noisy. In the atmosphere controls, click on the quality tab. Increase the number of samples to 32. It should look less noisy. The maximum recommended setting for this is 64.
The color of the land can be changed in the Shaders Tab. Click on the Base Layer, then the Color Tab. A color picker will pop up when you click on the color box.
Welcome to the forum. ;D
Hi DJ,
Welcome to the forums :)
How did you set this up? Is this stitched? How did you light the scene, with/without GI? How did you set up your atmosphere? Is there terrain under the dense atmosphere?
Quite some questions, so I PM-ed you about it to see if I can take a look at it. I've never seen something like this before.
The bottom looks quite dense so the maximum of 64 samples is possibly the minumum level to start with.
The thicker/denser the atmosphere the more samples one needs in general, so there's no hard limit to that at all.
Cheers,
Martin
Wow fast reply's. I e-mailed you with the file Tangled Universe.
Also. The quality is so low because these are quickrenders. I see the errors all over them and i dont want to spend 20 minutes rendering with these errors :).
The Planet Surface is desabled. It does not show anymore, so the black line in the center of the screenshot has been fixed. But now I am still getting these weird black rays.
Thanks again for the replies!
I suspect it are the shadows of the the clouds. The blackspot is south of he sun, located in the north. I want these shadows not so strong on my haze.
Hi Dirk Jan,
I examined your file in notepad and saw you don't use any weird settings.
The atmo samples AND cloud samples should be increased though.
Both are at 16, so for atmosphere I'd start at 64 and that probably won't give the smoothest result, but will be a good start.
The cloud samples is a bit of different story. Don't look too much at it. The quality setting is the most meaningful and in general a value of 1 should give very good results. The number of samples required to achieve a detail level of (say) 1 depends on the cloud's density, depth and edge sharpness.
Therefore it's not very meaningful to say "I still have noise in my clouds while I use 256 samples".
So, for starters I'd also increase the cloud's quality to about 1.
To make the clouds' shadows less dark you could try a couple of things.
The strong shadows are probably cast due to: high density of clouds or too low light propagation settings.
You could start decreasing density of the cloud. This will make the clouds brighter (as there's more influence of the glow) so compensate for that with the diffuse and scatter colour. If this does not work then increase the "light propagation" (cloud node). Increase it with 2-fold increments and make test-renders.
Be aware that you're not limited to the sliders maximum value. You can enter any numerical value in a field and throw it at the renderer.
Cheers,
Martin
Thanks alot. I will try this out tomorrow when I am back at work to see how much it affects my skies. Thanks!
I rendered it at 64 atmosphere samples and cloud quality at 1. It's not entirely noise-free but quite smooth I'd say.
The dark pinched rays at the left of the centre is the centre of the atmosphere node I think.
The position of the atmosphere-node is @ -6.378e+006 metres and has a radius of 6.378e+006 metres, because the planet has the same position and radius.
Since you have disabled the planet I think that that's what you are seeing.
Perhaps TG2 isn't designed to render these rare conditions where there's no planet but only atmosphere.
Martin
Terragen seems to have a "cut off" point below the planet horizon beyond which the atmosphere is not rendered whether or not the planet surface is enabled. I don't know if this is your situation...
Also the phenomenon you see of converging shadow lines in the lower half of your image is an entirely natural (if a little uncommon) one known as Anti-crepuscular rays (http://www.atoptics.co.uk/atoptics/antray1.htm)
Ricchard
Quote from: cyphyr on November 24, 2010, 12:23:01 PM
Terragen seems to have a "cut off" point below the planet horizon beyond which the atmosphere is not rendered whether or not the planet surface is enabled. I don't know if this is your situation...
Also the phenomenon you see of converging shadow lines in the lower half of your image is an entirely natural (if a little uncommon) one known as Anti-crepuscular rays (http://www.atoptics.co.uk/atoptics/antray1.htm)
Ricchard
What you describe first is the "floor" setting in the atmosphere node. I've tested this and this is not the problem.
At default it is -16000m and the converging shadows are at about -5000m I'd estimate roughly.
Which makes me think now that my thought about the centre of atmosphere doesn't make sense at all :)
Maybe it are indeed Anti-crepuscular rays!
Martin
Quote from: Tangled-Universe on November 24, 2010, 12:38:41 PM
What you describe first is the "floor" setting in the atmosphere node. I've tested this and this is not the problem.
At default it is -16000m and the converging shadows are at about -5000m I'd estimate roughly.
Ooh must test this, it may be a solution I've been looking for :)
Richard
The dark rays in the atmosphere are caused by shadows cast from the clouds. The point where all the rays converge to one point is where you are looking directly away from the sun. Since you are not rendering the planet's surface, you are looking very deep into the atmosphere, something none of us have ever seen in real life because the ground is never more than a few kilometres below us, so it looks a bit strange when we can see so deep into the atmosphere, but not necessarily wrong. (But I guess if you could see this in real life there probably would be more scattering which would make these deep rays less prominent.)
The really dark rays are below the horizon. The first question I would ask is whether they will even be visible inside the game or environment where this skybox will be used. Even up to a few degrees below the horizon your rays are not excessively dark - it is only when you look much lower that they seem too strong.
You can reduce the contrast of the rays by adding more environment/ambient light to the atmosphere. Either one of the following will work: Increasing the "strength in atmosphere" setting on the Enviro Light node, or increasing the "Ambient" setting in the Atmosphere node. Doing this will weaken the rays where you probably do want them though. The rays above the horizon seem nice and natural, and if it were me I would not want to diminish those.
EDIT: Make sure that your render settings have both "GI relative detail" and "GI sample quality" at 1 or higher, otherwise your Enviro Light will have no effect. The Enviro Light is needed to lighten the shadows by accounting for scattered light.
Enabling soft shadows on the sunlight might help to soften the rays a little bit. It might keep the rays where you want them but diminish them over longer distances. But be aware that soft shadows will probably increase noise which you would need to compensate for with higher number of samples in the sunlight node or in the atmosphere node (or both).
Matt
It has been a while and I want to thank you all for the support.
Goodluck!