problem recreating TG09 sun in TG2

[shadowphile]

I liked this sun I had in TG09 (see image), where the flare blends evenly into the sun and falls off rather sharply, with some leftover ambient fall off.  It might not be accurate but I think it has great perceptual reality.

I can't recreate it in TG2.  The only tool to add the halo is the atmosphere shader, with power and intensity.  That doesn't work right and I have to put extremely large numbers to even get close to the look.
Otherwise, the sun just looks like a sharp disk.
I've played with many other settings without results.
Anybody help me out?
thanks

[Henry Blewer]

Matrix did some T2 renders a few months ago. The sun had image maps applied, looked very cool. (I do not want to be Paris Hilton, rich yes, but the h_ word no) You might put a camera in front of the sun. Then use a distance shader on a cloud layer so the cloud is tight in front of the sun. Use a low density on the cloud. I'm not sure this is what you a wanting, but it could be a neat effect.

[Seth]

I agree that it is not the same but after only 2 minutes of tweaking, i get this...
so I really don't think it should be too hard to reproduce your TG0.9 sun...
and I don't see what's wrong about "extreme" values... they are just numbers... don't be afraid of them

[Tangled-Universe]

I must admit I also spent about half an hour on this but couldn't achieve the same effect. Well, a little, but not like this.
I'm happy you posted this, otherwise he'd have to play with my crappy suggestion

I think you should make a sticky topic with the title "values are just numbers"

Martin

[choronr]

I agree that it is not the same but after only 2 minutes of tweaking, i get this...
so I really don't think it should be too hard to reproduce your TG0.9 sun...
and I don't see what's wrong about "extreme" values... they are just numbers... don't be afraid of them

Thanks Seth, this is a valuable piece of information.

[Seth]

just keep me in touch with your advancement on getting closer to your TG 0.9 sun.


@Martin : lol ! 

[neuspadrin]

Well, with terragen you either

a) can use super high numbers just go for it and see what happens
b) dont use them on render quality settings.. usualy high = VERY VERY high.  Don't bump up "Quality" to 100 good luck with that...

[shadowphile]

thanks for the inputs folks.
Seth, your result was the about the type of sun I was getting, but the TG09 has a harder edge that I kept trying to sharpen by increasing the glow power and compensating with lower intensities.  I was down to 1e-11 intensity and powers of 10.  I started getting a donut effect and the sun disk edge was still discrete.  Also couldn't pull in the glow edge beyond a certain point, just wouldn't get any smaller.
I was concerned with the extreme numbers because if I have to use extreme measures to do something supposedly simple (like in TG09), then maybe I'm using the wrong tool...   

Turns out my biggest problem was the disk size.  I had a 6 deg disk in TG09, had to drop it to 1.5 in TG2.  For some reason too large a disk can't blend well with the atmo halo.
I still need to add that fainter streaming asymmetric glow but this is a good start. (probably a low-altitude effect)
I should go back to TG09 and see exactly what it does there.
For the curious:
sun strength = 6
haze density = .08
bluesky density = .47
haze glow amount = 1e-6
haze glow power = 6
bluesky glow amount = .015
bluesky glow power = .75
enviro light = .19

[Seth]

I guess TG 0.9 was more far from real atmosphere than TG2 is... that's why you may have some problem to reproduce something absolutely unreal with it.

[Matt]

TG Classic rendered a halo/corona around the sun, in addition to the glow in the atmosphere. TG2 doesn't do that because it's not particularly realistic, but you can create a similar effect by using a second atmosphere with different settings to produce just the tight glow around the sun. The wider "streaming" glow comes from the default atmosphere.

Start with a default atmosphere. Reduce camera exposure to 0.25 (or -2 EV on the slider in the preview). Then paste in the following and connect it in series with your default atmosphere.

Code Select Expand


<terragen_clip>
<planet_atmosphere
name = "Tight sun glow"
gui_use_node_pos = "1"
gui_node_pos = "0 180 0"
gui_group = ""
enable = "1"
input_node = "Atmosphere 01"
gui_use_preview_patch_size = "0"
gui_preview_patch_size = "1000 1000"
enable_primary = "1"
enable_secondary = "0"
centre = "0 -6378000 0"
radius = "6378000"
seed = "0"
haze_density = "0.100193"
haze_horizon_colour = "0.349999994 0.349999994 0.349999994"
bluesky_density = "0"
bluesky_horizon_colour = "0.224999994 0.3585940003 0.4499999881"
bluesky_additive = "0"
bluesky_additive_colour = "0.05000000075 0.270938009 1"
redsky_decay = "0"
haze_exp_height = "3000"
bluesky_exp_height = "8000"
ceiling_adjust = "7"
ceiling = "56000"
floor = "-16000"
haze_glow_amount = "1"
haze_glow_power = "3"
bluesky_glow_amount = "0"
bluesky_glow_power = "0"
enviro_light = "0.5"
enviro_light_tint = "1 1 1"
ambient = "0 0 0"
fake_dark_power = "0"
fake_dark_sharpness = "10"
bluesky_density_colour = "0.1000000015 0.3400000036 1"
redsky_decay_colour = "0.9048374295 0.7117702961 0.3678794503"
improved_glow_model = "1"
number_of_samples = "16"
adjust_to_distance = "1"
sample_jitter = "1"
enable_ray_traced_shadows = "0"
>
</planet_atmosphere>
</terragen_clip>


I couldn't match the v0.9 image as closely as I'd like because you can't use very high glow powers without introducing artefacts. But it's not bad.

Matt

[aymenk2003]

         

[shadowphile]

thanks Matt, I will give it a try, after I finish the current (loooong) render.
I wouldn't have recognized what you were coding except I just happened to dig into a TGD file to fix a problem with Neon22's batch file.  I know just where to paste this.

[Matt]

Just in case you didn't know, you can paste this into the node network in the GUI (it's just a node copy/paste clip). No need to edit the .tgd file.

Matt

[shadowphile]

ah, good to know.  You mean paste into a text file with a .tgc extension and then importing it, right?  Can't see a more direct way to paste directly into the GUI.

[FrankB]

just click into the node network view once and then ctrl+v