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View Full Version : Trying to get a glowing crystal/ice effect... help?


SanguineJackal
09-03-2011, 06:26 PM
Hey guys,

Been a while since I've had the time (and since my computer has had the power) to work in 3D, but I'm back on it with an ambitious project for a contest that finishes at the end of this month.

The contest is to design a game environment and render a video of it. No biggie, except I've never modeled an environment in 3D ever.... I've never even made a concept painting of one!

So I am modeling some of the smaller stuff (modular?) to stick into the environment. After I've done that I'll work on the actual terrain. I am of course using Softimage (and will later be using Sculptris to help with some of the stuff to bake).

But I am hoping to get some glowing crystal pieces and/or glowing "ice" if you will. It's on an alien planet, a glacier cave almost but the mountain the glacier covers has rich crystal deposits. And I want a subtle glow to give the cave some illumination, a la FFX's Macalania Woods....

http://static.desktopnexus.com/thumbnails/371997-bigthumbnail.jpg
http://2.bp.blogspot.com/-Wa7qdMIQrhk/TW3aFx3XHGI/AAAAAAAAAbw/INYqWWbxY_U/s1600/Tribute_to_Macalania_by_MelancholiesChild.jpg

...And to give the ice shelves that almost eerie illumination they always seem to have.

http://ericguthphotography.files.wordpress.com/2011/03/glacier-caves-12-of-19-e1300005541362.jpg?w=499
http://www.deviantart.com/download/255623211/turbulent_by_ivanandreevich-d486w4r.jpg

Here is my speedpainted concepts, just playing with colors. But the crystals on the left were painted using reference and that's sort of the look I am hoping for.
http://www.conceptart.org/forums/attachment.php?attachmentid=1315021&stc=1&d=1315075266

Does anyone have any tips on achieving either of these looks? I've searched and searched and can't find anything quite what I need... :x

Ohmanoggin
09-06-2011, 09:27 PM
I would check into Sub Surface Scattering (sss). The ice formations you use as reference definitely display this phenomenon. There is a shader called "Fast Simple misss" in the illumination nodes in the render tree.

For the bright spots you see in the illustrations, you could apply a lens flare property to lots of lights, using the star and glow options.

Hope this helps,
Ohmanoggin

pelos
09-09-2011, 06:18 AM
what he is mentioning is setting up Sub surface scattering into the material for the rocks.
before jumping to SSS, i would like to know do you need to make this in a game engine? what type of material does the engine support? or just model it and render it?

if not, before jumping into SSS that takes long to render i might consider just regular reflecction and refractions plug into a incident gradient from the camera. if you have access to a post effect add a glince effect on that too.

SanguineJackal
09-10-2011, 04:47 PM
I would check into Sub Surface Scattering (sss). The ice formations you use as reference definitely display this phenomenon. There is a shader called "Fast Simple misss" in the illumination nodes in the render tree.

For the bright spots you see in the illustrations, you could apply a lens flare property to lots of lights, using the star and glow options.

Hope this helps,
Ohmanoggin

I noticed a couple different SSS shaders in there, and just playing around with them I got some interesting results but not quiiiiite what I was looking for. But frankly, I was just playing around with values.... I don't know half of what I was changing!


what he is mentioning is setting up Sub surface scattering into the material for the rocks.
before jumping to SSS, i would like to know do you need to make this in a game engine? what type of material does the engine support? or just model it and render it?

if not, before jumping into SSS that takes long to render i might consider just regular reflecction and refractions plug into a incident gradient from the camera. if you have access to a post effect add a glince effect on that too.

We don't have to make it in a game engine; just model and render, and animate a flythrough. No animations, no game physics, poly limit, etcetera either. Something about the SSS I put on that ice looks a bit off though.

Ohmanoggin
09-13-2011, 02:21 PM
Play around with the location of light sources. Try putting one behind the object.

Ohmanoggin

ViCoX
09-13-2011, 07:06 PM
Like Pelos said. Forget the SSS, it has very little do with crystals. Same goes for diffuse, it should be close to 0.

What you should be focusing is reflections, blurred reflections, refractions and LIGHTING.
Crystals reflect and refract so normal lights wont cut it because they woth show in reflections or refractions. (yes you can turn it on in area lights)
Use surfaces that emit light. You can even use HDR taken from real light source ect.

Once get good looking stuff with those, start playing with SSS.
There is HUGE over use of SSS in 3D for some weird reason.

SanguineJackal
09-14-2011, 05:02 PM
Like Pelos said. Forget the SSS, it has very little do with crystals. Same goes for diffuse, it should be close to 0.

What you should be focusing is reflections, blurred reflections, refractions and LIGHTING.
Crystals reflect and refract so normal lights wont cut it because they woth show in reflections or refractions. (yes you can turn it on in area lights)
Use surfaces that emit light. You can even use HDR taken from real light source ect.

Once get good looking stuff with those, start playing with SSS.
There is HUGE over use of SSS in 3D for some weird reason.

I've never messed with HDR before. And sadly my lighting abilities are... rather pathetic, to be honest. But if this is going to be a cave and the walls are meant to glow from the outside in, and provide some of the light, while the large crystals dotting the ground provide the stronger light, getting them to refract off of each other shouldn't be a big issue, right?

Like this:
http://farm5.static.flickr.com/4061/4426427851_fbc1e0ee23.jpg

That's all caustics and such, correct?

I only have Softimage, so I'm trying to figure out how to set up a decent looking shader for the right look. The best shader I've seen is for Cinema4D, there's not a lot available for XSI sadly...

EDIT: Found some basic glass stuff while messing with menus in there and am trying some stuff out...

Ohmanoggin
09-14-2011, 09:53 PM
"...But if this is going to be a cave and the walls are meant to glow from the outside in"

You are essentially saying light is scattering inside the surface from the outside, that is sub-surface scattering.

Have you tried putting a bright light behind your object (relative to camera)? I realize sss can be tricky to get going, but once you see the glowing effect you can tweak it to your needs. If you still can't see it try this:
1. Get Primitive / Character / XSIman.
2. Connect Fast Simple sss to the material node.
3. Place a point light behind the man and increase intensity to 3.
4. Draw a quick render region over it with Q.

You should see the effect. Now you can play with properties to see how they effect the scattered light. Also try different light setups.

To render with HDR images try this:
1. Render / Pass / Edit Current Pass.
2. On the Pass Shaders tab hit add and select the environment shader.
3. Select and HDRI image. You can get these for free off web. Let us know if you need a source.
3. Move the Background slider to 0, or you will see the environment texture in the background of renderings.
4. Render / Render / Render Manager / Final Gathering (tab). Turn on FG to see when you Preview or Render.
or Render / Regions / All Options to see in render regions (Q).

When you turn on Final Gathering and use an environment shader, you are using image based lighting. The environment shader, is similar to having a large sphere over your scene, with a texture applied to the sphere. If you put a sky texture, all your reflections would see a sky. In this case, we used an HDR image which has a larger range of intensity giving a more powerful effect with image based lighting. If you made an HDR textures from photos of a live environment, the object you are rendering can appear to be lit similar to the real environment. This is a common use for image based lighting.

For final gathering, you do not need light from light sources. However, you need one light to exist for FG to run. You can turn light intensity to 0 if you do not want light to contribute.

You can also place grids or other surfaces in the scene to light it with FG. Just apply constant white for pure white light, or textures as desired.

P.S. I am assuming you know what FG is. There are many sources on the web for good info and Softimage help and user guide has some good info too.

Hopefully this will get you started.
Ohmanoggin

Ohmanoggin
09-14-2011, 10:05 PM
You mentioned "caustics" but that is more useful if you are trying to see how light projects on objects after it passes through a transparent medium. For example, a shark underwarter picks up light patterings from the waves on the surface.

However, caustics is very expenstive to render and effects like this are easily faked by using a slide project shader on a light source which renders instantly. Caustics still might be useful, but you are bighting off a lot already.

Ohmanoggin

SanguineJackal
09-14-2011, 10:32 PM
After much searching, I found a good "ice cube" shader... honestly a simple Google search sufficed but I crawled through the Autodesk forum and some others first, silly me.

This is kinda what it looks like, and will probably work well for the crystals.

SanguineJackal
09-14-2011, 11:00 PM
Ohmanoggin, I'll give those a try. We're about to run out the door but I'm playing with the XSIMan character. :D

SanguineJackal
09-15-2011, 06:32 PM
Have you tried putting a bright light behind your object (relative to camera)? I realize sss can be tricky to get going, but once you see the glowing effect you can tweak it to your needs. If you still can't see it try this....

Got it. Played around with the settings and found what I wanted! Now if I could just make the surface shiny I'm all set!

To render with HDR images try this...

I keep getting the error "File Does Not Exist" whenever I click any file. What the heck?? :(

P.S. I am assuming you know what FG is. There are many sources on the web for good info and Softimage help and user guide has some good info too.

Hopefully this will get you started.
Ohmanoggin

Yep, it's been a while since I messed with FG but I have used it before. I think in that class we just mapped an HDRI to a sphere as a texture and then used FG....

Ohmanoggin
09-15-2011, 08:24 PM
Q: Now if I could just make the surface shiny I'm all set.

A: There is a setting for specular color to boost the highlights on the surface.

However, now might be a good time to look at "Passes" and "Partitions". This will let you override your current material, and isolate elements of your rendering to composite on top of the original. In your case you can isolate the reflections or specular highlights and add those the the matted color of the SSS in the main pass. If this sounds useful read up on Passess and Partitions and also Render Channels. Partitions are nothing more than a directory list of objects. Your scene creates two partitions, one for all objects and one for all lights. You can create your own partitions with specific objects and then select a partition and perhaps add a new material like Phong or Architectural Shader (for something shiny) to override all the materials that have already been applied. Let us know if you have some difficulty on these topics. Doing everthing in the render tree is another option, but you will definitely need to master Passes anyway.


Q: I keep getting the error "File Does Not Exist" whenever I click any file. What the heck??

A: I read .hdr files all the time. Hmmm. Any chance you selected the zipped file instead of the texture? Here is a link that has some good hdr images.

http://xedium3d.com/tutorials/hdri/
http://ict.debevec.org/~debevec/Probes/
Download all_probes.zip (Just above first image).
try the image: "rnl_probe.hdr" it has a good range of colors.

Hope this helps,
Ohmanoggin

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