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Mr.Pants
04-23-2004, 02:00 AM
anyone know how i could go about getting this effect i tried using a water shader and messing with it but i just can't get it right
http://www.dnull.com/stargate/stargate-small.jpg

lazzhar
04-23-2004, 02:08 PM
Water Shader wont be enough until you combine it with some other shaders so you perturb the regularity. Then apply it as a bump map.
I wish I could try acheive something like that it needs too much time.
Good luck.

redfuzz
04-23-2004, 11:06 PM
Originally posted by Mr.Pants
anyone know how i could go about getting this effect i tried using a water shader and messing with it but i just can't get it right
http://www.dnull.com/stargate/stargate-small.jpg

Ah..... the stargate puddle.

I've had the pleasure of working on every season of stargate since the pilot. Over the years I've worked at various companies here in

The Puddle is a bit of an inside joke because the vfx supervisors are always telling different artists to match other artist's work, but over the years it has evolved to be far different that the pilot. Partly do to migratring through may hands and many visions and many softwares.

Originally I would do the puddles in Alias Power Animator, I have done some in Maya (early versions), I have heard that they were occasionally attempted in Lightwave. I may be going senile, but I think I did the ones in the pilot in Softimage (pre XSI).

When I rebuilt them from Alias PA to Maya I remember being very keen to keep render times to a minimum. Thus raytracing was avoided as it was used previously.

The ripples that people create as they walk through them are all hand placed and timed, and you can't really see the true effects of that till it's rendered, so quick turn arounds meant more accurate ripple line ups. Also a certain amount of flexibility is required as the desired look can change a lot depending on what environment the puddle is in. I remember much talk of the 'flecks of light' around the bright center, and how different people liked to see them different ways.

My basic memory of it was a Nurbs Circle set to a planar trimed surface. The shader was a blinn (good control of specular and reflection). The reflectivity had a ramp with a facing ratio sampler info attached for a fresnel effect. the color was a dark blue circular ramp. The specular was tight and bright. The bump was the water shader (not the new fancy ocean shader) with another water shader in the color gain to give a good variety of wave sizes. The majority of the look came from a reflection map. Don't forget to connect the outnormal of the bump to the normal camera of the envirnment sphere of the reflection. The environment sphere used a circular ramp with whit in the center and dark blue on the edge, this was color gained with a number of fractals (but youd be surprised how much of the 'light flecks' come from the distortion of the bump map and not the fractals) to get the 'flecks' just right. When this ramp was reflected and distorted by the bump map all was good. To control the placement of the bright spot (which would change the angle the puddle was viewed from, the environment spere placement node was rotated to that the bright spot of the reflection ramp was always nearly behind camera. The ripples for the pass through is the water shader (maped to the color gain of the bump) with the waves turned off and the ripples turned on, ripple time is animated and the projection node is used to place it. Then it goes in Flame/Inferno for glowing and rays and a hand painted reveal matte for the pass throughs.

Either that or I'm crazy....

I'm working at Rianmaker now and I know that a guy here does the puddles in Power Animator still. They have one old lonely copy sitting on an old lonely sgi octane. Perhaps I'll see if he want to add his two cents...I think that this year, with the Atlantis spin off and all they are trying to do the comp in Fusion, but I guess they will have to make sure it matches the same setup on the flame... might be able to track that guy down too.

g

Mr.Pants
04-24-2004, 03:16 PM
Originally posted by redfuzz
The reflectivity had a ramp with a facing ratio sampler info attached for a fresnel effect

thanks for the info i tried doing what you said but when i got here
i did the sampler info utility and i picked the facing ratio but what do i attach to it on the ramp should i do everything on the list

i am using maya unlimited 5.0

redfuzz
04-28-2004, 04:44 PM
from the sample info connect facing ratio to the ramps uv coord V
tis tells the shader that is a normal is facing the camera (=1) then take the color of the ramp at V coord 1 (top of a default ramp). If the normal is facing perpendicular to the camera then the shader takes the color from V coord ) (bottum of ramp).
There is the chance that I'm carazy and got the top and bottum reversed, but I think that's it.
This way you can get a high (white) reflectivity araound the edge of your object and a lower (dark) reflectivity in the center. This is the effect know as fresnel's law or some such.

Check out the ramp shader it dows all sorts of things liek this, all built in for you now.

I think MR. Fresnel was also into light house lens design.
Mr.Fresnel (http://www.the-worms-of-art.com/ContFiles/Tutorials/58-Fresnel.pdf)

The other connection to consider is the output of the bump maps normal camera into the reflection environment sphere's normal camera.

cheers
g

lazzhar
04-28-2004, 05:36 PM
Mr.Pants

The facing ratio could be always cnnected to the V attribue of a Ramp (or to its U if you're using is) then the output of the Ramp is used then.

Gremlin
04-29-2004, 02:09 AM
isnt that sweet having the person who actually made the effect help you out? lol, kudos to cgtalk.com

anywho, i made a shader a year ago that actually looks a lot like that (i can post it if u want) but it was basically just a fractal bump, and some facing ratio color / reflectivity. :D

Cheers,
:beer:

redfuzz
04-29-2004, 04:34 PM
From the compositor who is doing some puddle shots here at Rainmaker. He's talking about the effect of the actors entering the water, which is hand rotoscoped.
g

From: Mathew Krentz
Sent: Wednesday, April 28, 2004 7:03 PM
To: redfuzz
Subject: RE: AT "Rising" - pd 052x03 Puddle Notes

Hey, I don't have a cgtalk account, else I'd help out.. basically to get the feel of depth, it's all done in 2d and I just offset the pass through elements of the actors, color correct it and blur the edges to give fall off. Not sure if that helps out at all. :)

mat

viker
04-30-2004, 01:06 PM
If any one of u actualy manages to make the effect, can u post a pic ! To see :) And compare :P

lazzhar
04-30-2004, 04:20 PM
Originally posted by redfuzz


Hey, I don't have a cgtalk account, else I'd help out..

mat

What a poor guys :( .. i have a second one just send me an email and i'll give it to you ;)

But how easy to do things in 2d while we spend too much time on 3d !!!
Thanks man for sharing :)

SSJTitan
08-27-2005, 10:01 AM
Does any body know how to create the water effect using Lightwave?

Thanks, SSJTitan.

cpan
08-28-2005, 06:50 AM
i did smth similar to that with a softbody nurbs surface:

create a circle and planar it, then select the surface and make it softbody. Then select it's particles and add a turbulation (or what ever it's called) field. Adjust the magnitude, etc and watch the animation :)

now all you need is to create a realistic material that fades from the interior to the exterior of the gate (smth like a ramp + sampler_info material) and has noise textures on the reflection/specular channels etc.. hehy hope u understood smth ;)

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