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Planet Aura

laynemoorelaynemoore Posts: 0
edited December 1969 in Carrara Discussion

I'm a newbie - let's get that out of the way. I'm running Carrara 8.1 Pro on an iMac OSX Lion. I animated a simple 7 second scene of the camera slowly panning around earth while it rotates. It will be part of a ship flyby.

I created a blue aura that looked the way I wanted in the render preview. Doing the final render, I get a thick over saturated glow around the outer part of the planet that looks nothing like my preview. I messed with it for an hour last night but couldn't figure it out. Any ideas? Even better - is there a good tutorial for planet glow?

Also, the final render showed the planet rotating but the aura also rotated away leaving the final few seconds with no glow. :(

Comments

  • 3drendero3drendero Posts: 2,027
    edited December 1969

    A screenshot would make it easier to understand, here is a guide that may be what you need:
    www.sharecg.com/v/47716/related/3/PDF-Tutorial/A-glow-effect

  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    Aura is a really bad post effect. I never use it because it always looks pixelated and granular, and it doesn't respect any scene scaling, just pixel width (I think).

    If you have any of the plugins that give a fresnel (falloff) effect, you can make another sphere that glows blue (slightly large than your planet and cloud spheres) and set it's transparency with falloff so you can only see the edges. This will give your planet a "halo". Without falloff the transparency won't look very good...

    Carrara's transparency shader has a fresnel setting as of C8..., but I am not familiar enough with it to offer settings suggestions...

  • FenricFenric Posts: 351
    edited December 1969

    I second Holly's suggestion: use a second sphere with Transparency (not Alpha), slightly larger - not the Aura effect.

  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    I just tried to work with the built in fresnel, but I do not think it can be purposed for this...

  • Jay_NOLAJay_NOLA Posts: 1,145
    edited November 2012

    See the 2 Faking Atmosphere videos at:

    http://www.markbremmer.com/3Bpages/darkarts.html#p7GPc1_5

    One is a tutorial and the other video shows you a rendered scene using the technique.

    Also are you just using one sphere with a texture one it for the planet or multiple sphere with your ground terrain on one and your clouds on a slight larger one surrounding the ground terrain one.

    Post edited by Jay_NOLA on
  • evilproducerevilproducer Posts: 9,050
    edited November 2012

    I rarely disagree with Holly or Fenric, but I'll do it here, with some caveats. Here's a sample using the aura for an atmosphere effect that I did awhile ago:
    http://www.youtube.com/watch?v=c2XfqXVtGAQ&feature=share&list=UU6wB1FKPN4DWpuoVsQY2o8Q


    The video uses three spheres. One for the planet surface, one for the cloud layer and one for the "atmosphere." For the atmosphere I used a medium blue shader in the color channel, a numerical slider in the alpha channel set to 1%, and a light blue color in the glow channel. I'll include a screen shots of the shader and the editor for the aura as I'm getting tired of typing.


    Here's the caveats: I wouldn't use the noise functions in the editor and since it's a post effect other post effects won't play nice with it sometimes. It also won't respect lighting as you can see from the dark side of the planet. I just call it "atmospheric refraction." ;-)


    For the animation, I rendered the background layer and the planet separately and composited them in post. Mostly to save render time.

    Picture_2.png
    934 x 768 - 196K
    Picture_1.png
    784 x 501 - 95K
    Post edited by evilproducer on
  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    Here's a quick still render I did with the above settings.

    earth.jpg
    1200 x 900 - 217K
  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    I do see the atmosphere... :)

  • laynemoorelaynemoore Posts: 0
    edited December 1969

    Evil, I will attempt this when I get home. I hadn't thought of using multiple spheres. One of those smack my forehead moments. This forum is great. I appreciate the ideas and your time.

  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    You can also use the "Light sphere" effect, on a bulb, placed at the centre of your planet, although it can be fiddly to set the distance, it's effect is nice (IMO) and worth the time.

    If you don't want to take the time,. here's a scene . https://dl.dropbox.com/u/7907045/planet_fly_in.car

    The shaders for the planet and clouds are all procedural, ..but you can obviously replace those with maps or other shaders.

    earth_bulb.jpg
    800 x 600 - 34K
  • thoromyrthoromyr Posts: 452
    edited December 1969

    Although aura may not be the best solution for the issue at hand I would not dismiss it as useless. Certainly it has provided just the right touch to images for me in the past. It can certainly be fiddly to tweak, though to a great extent that depends on how you are trying to use it.

    I don't know if my example here shows how nice it can look (the image was rendered for print as a poster and looks much better that way), but it certainly makes extensive usef of Aura...

    The_Jellies-1280x720.jpg
    1280 x 720 - 141K
  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    I Agree with Evil producer and Thoromyr, the glow shouldn't be dismissed . but I'm also thinking that if Holly and Fenric are suggesting not to use it ,..then there may be some differences with how this effect is working on the different platforms,. and it may be worth posting a couple of Pics,. so we can see if it's something that's visibly different on PC and Mac.

    My main issue with using the aura in this instance is the fact that it uses Glow in the shader, to power the effect, and it produces an all round light effect.
    The Sunlight should cancel out the effect on the part of the planet facing the light.

    Also Note:
    in the scene I posted above,.. I've left a (hidden) plane (vertex grid) which I had set up with a point at (camera) modifier, and it has a radial gradient shader applied to it, to create the same type of fake aura as you see in Mark Bremmer's tutorial, but using shaders instead of image maps,. this is ok-ish,.. but the effect is all round the planet. ...so I just made it invisible.

  • FenricFenric Posts: 351
    edited December 1969

    No, I don't think the built-in fresnel will do. Go get sparrowhawke's free falloff shader and use that.

    http://www.sparrowhawke3d.com/Sparrowhawke3DPlugins.html

    I didn't mean to suggest that you should ignore Aura forever for everything, just that I don't think it gives a particularly realistic atmospheric shell.

    http://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57723/globe_east_2048.jpg

  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    I was trying to get something useable without a plugin... Carrara's built in fresnel works to make the center of the refractive object show it's effect. For a good atmosphere glow you'd want the edges to show more effect....

    I tried using some other shader tricks: light scattering, translucency.... Some things might work in certain circumstances, but Glow and a fresnel filter is easiest.

    If you are feeling confidant you could use a SPLAT painted with a glowing ring. Parent the SPLAT to your Earth/Clouds group, and make the group point at the camera. Totally fake, but totally controllable...

  • thoromyrthoromyr Posts: 452
    edited December 1969

    3DAGE said:
    so we can see if it's something that's visibly different on PC and Mac.

    I could post some, but all you'd find is that they are identical. I'm almost 100% OS X now (still run Carrara in Wine on linux occasionally), but I've done a fair amount of crossplatform rendering. There may be some area where they do differ, but I've never encountered it.

    My main issue with using the aura in this instance is the fact that it uses Glow in the shader, to power the effect, and it produces an all round light effect.

    It certainly isn't the right choice in all situations.

  • thoromyrthoromyr Posts: 452
    edited December 1969

    holly wetcircuit said:
    I was trying to get something useable without a plugin... Carrara's built in fresnel works to make the center of the refractive object show it's effect. For a good atmosphere glow you'd want the edges to show more effect....

    Did you try subtracting the fresnel from a value?

  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    thoromyr said:
    holly wetcircuit said:
    I was trying to get something useable without a plugin... Carrara's built in fresnel works to make the center of the refractive object show it's effect. For a good atmosphere glow you'd want the edges to show more effect....

    Did you try subtracting the fresnel from a value?
    I'm not sure that would be possible because of where the fresnel control is located. It is not in the "tree" so I am not sure how that could work....

  • thoromyrthoromyr Posts: 452
    edited December 1969

    ah, never mind. I was thinking of Fake Fresnel which is an add on

  • RoguePilotRoguePilot Posts: 239
    edited December 1969

    Hi,

    If you really want to do this with just the built in shader functions, try the fresnel setting in the SSS channel.
    I'd still use a little blur on the SSS layer in post to soften the edge.

    http://fav.me/d5hfc0s

    http://fav.me/d500ijs

  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    RoguePilot said:
    Hi,

    If you really want to do this with just the built in shader functions, try the fresnel setting in the SSS channel.
    I'd still use a little blur on the SSS layer in post to soften the edge.

    http://fav.me/d5hfc0s

    http://fav.me/d500ijs


    Nice work on those!

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