Planet Ring

Started by CCC, February 20, 2010, 06:29:02 PM

Previous topic - Next topic

dandelO

When I get a bit of spare time I'll make a full sized example version. Maybe later tonight, probably tomorrow.
I'm wrestling with some cumulus cloud at the moment or I'd do it now... :)

CCC

Don't feel to disappointed about this. I tried scaling up there sizes as well. I made sure the ring were larger then the full-scale planet. I can see the boundary lines but when rendered nothing would show.

dandelO

#47
I'm on it now, next few minutes. You might be pleased to know that the setup was over complicated before, the simple shape shader isn't required at all(I'm still using its inverse to remove an empty space around the planet, this means that you can use a cloud height of 0 and no need to work out weird e+00x numbers for that parameter). The surface layer altitude constraints do a grand job on their own...

dandelO

#48
OK.

Here's a true planetary scaled version(default TG new planet size). This is an easy way to lay a ring around the planet using a cloud layer.

The surface layer's altitude constraints supply the cloud's Y-cut-off limits, the simple shape shader now only describes where clouds shouldn't render. You'll notice shadow casting from both directions - from planet and from ring. Enable ray traced shadows in the cloud layer for this effect.

Again, this is only one layer, you could add as many intersecting cloud layers as you want or, use some kind of circle function for distribution of the same layer, it's up to yourself and whatever you need. This is just an example to build on or use as a reference.

You'll need to assign your own ring distribution functions etc.(like I did with the sin functions above) but this is a basic form for laying a ring layer around the planet using clouds. Nearly 10,000 samples! Lucky it's only a shallow layer, eh! ;)

[attachimg=#]

[attachimg=#]

* You might try rendering this from beneath the planet, I haven't tried that yet so, any render errors, let me know and I'll see if I can iron them out...

dandelO

#49
* Seems almost fine from below the planet. I've spotted a strange line of lighting across the planet's surface, though. I'll try to work out what's causing this tomorrow...

[attachimg=#]

Thanks for the prodding, AL33, I would have never attempted this if not for reading your first post. :)

CCC

No worries, i will try and get a nice surface render going here. 

CCC

Alright, how do you apply the ring to the default planet and dump the second planet? I want the ring and a atmosphere as well. I tried re-routing all of the second planet internals to the the default planet but the ring size needs to be readjusted as right now the sizes allude me and i can not set my camera position on the surface as the current camera position is all weird. No rush to get this figured out today.

dandelO

The default planet's scale is the same as a new planet's scale - Radius = 6.378e+006. You should be able to cut the internal nodes of my uploaded planet and paste them inside the default planet(or, just paste them after the default atmosphere in the main network view) and zoom out for the same effect.

I'm rendering overnight just now, I'll give it a proper go tomorrow. To get the co-ord's for the simple shape shader cloud removal mask, enable 'show b-box in preview' on the default planet and copy the co-ord's from the centre of that to the simple shape shader to line it up correctly... I think that should work correctly.

You'll also need to edit the surface layer's altitude constraints to match the default planet's 'Y' value, it's set up for the floating second planet just now. A little on either side of centre is all you need, see the constraints in the example file, in relation to the example planet's 'Y' value...

CCC

OK, i'll see what happens then. Thank you.   

CCC

Well, i am very certain i have all of the sizes down according to what you said but here is what i did in case i might have overlooked something.

CCC

You know what. I did not have ray traced shadows check marked in the original file i had posted.  ::)  One other issue i am having is no color is showing on the ring itself.

dandelO

In your last post, the sunlight is significantly below the ring. It can't illuminate the ring's top surface from beneath, this is why you don't see any colour on the ring.

I've scaled up the power fractal, it was very small at default size.
If you really need to keep the same sun position, use a little luminosity in a default shader, like this edited.tgd uses.(this will stop you getting much shadow from the planet, mind. I'd raise the sunlight and forget the luminosity for best effect).

Also, I've used the opacity channel to remove some parts of the ring so it looks like it's made up of lots of little pieces and not just a solid ring(this doesn't seem to translate to the ring's shadow, though, sorry).

[attachimg=#]

[attachimg=#]

CCC

Quote from: dandelO on March 08, 2010, 04:26:01 PM
In your last post, the sunlight is significantly below the ring. It can't illuminate the ring's top surface from beneath, this is why you don't see any colour on the ring.

Sheesh, i should have known the obvious.    ;D

As for the file, looks good and once again i will get down to the surface and see what happens.


dandelO

#58
If you stay in the hemisphere above the ring, you should still see it, if you're below it, you'll need to invert the 'Y' axis of the disc(to -1). It's only single sided(and place your sun beneath it again, of course). ;)

CCC