Glass

Started by MGebhart, May 21, 2010, 05:50:46 PM

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MGebhart

Here is a Glass shader I made. I used a reflection shader and not a water shader.

If you noticed I turned off shadows. You will never get a realistic Glass shader until Terragen address light caustics.

NOTE: If I'm missing something, let me know.
Marc Gebhart

domdib

That looks good. Does it render quicker than a water shader? You're right that caustics would be nice, but let's not forget that Terragen is first and foremost a Terrain renderer. The fact it can do all this other stuff is just gravy.

dandelO

#2
I read Matt or Oshyan saying here before that Terragen will render real caustics if you use high enough GI detail and sample quality. I don't think a baseline was posted, just something like that phrase in an older thread, maybe about a year ago.
So, apparently, it's possible.

EDIT*

Quote from: Oshyan
Very cool results. The water topic has been set "Sticky".

In theory the GI may be able to create caustics, but I don't think it's really practical. Best to wait for a proper caustics solution which would not rely solely on the "fuzzy" GI.

- Oshyan

Sorry, I should have said 'may'. Not 'will'.

MGebhart

Hi D,

The render took 59 min.

Detail .9
AA 8
GI 2, 2, 8

Reflection samples 16
Refraction 1.15
Reflection 1
Specular Roughness .02

This is faster than the water shader by far and looks better.

I'll try the high GI settings but, it would be easier to fake the caustics in post production.
Marc Gebhart

MGebhart

Is it real or is it Memorex?

Low res render.
Marc Gebhart

Klas

Quote from: MGebhart on May 21, 2010, 05:50:46 PM
Here is a Glass shader I made. I used a reflection shader and not a water shader.
Place something behind the "glass". Is it visible or is this only a reflective sphere?

TheBlackHole

@Klas
Hmmm, how about the floor? ;D
They just issued a tornado warning and said to stay away from windows. Does that mean I can't use my computer?

Klas

@TheBlackHole
Hmm... the floor is mirroring in the sphere? Like the sun? Or do I miss something?

gregsandor

Nice, but an hour to render that is far too long.  What we need is a way to do glass fast with decent quality.  By the way the index of refraction for most common glasses is something between about 1.5 and 1.6.

MGebhart

Hi,

I was just fooling around with a fake photoshop caustics post work. Took about 30 seconds.

I agree with an hour taking to long and the refraction value. I choose the 1.15 because it looked the best.

Yes, this is transparent and not just a reflective sphere. If I get a few minutes I'll throw something behind it and render.
Marc Gebhart

jritchie777

I think you are on to something.  Did two exact renders except for the surface shader on the lake.
I did one with the default water shader, then I replaced it with the reflective shader.  It shaved 2 minutes off the render time.

Render with water shader:  5 minutes 37 seconds
Render with reflective shader:  3 minutes 30 seconds

You be the judge, but I like the reflective shader, thanks for sharing your work with us.  This will also help with some of my renders that I use water shaders for other effects, now I will use the reflective shader instead!

JR

Seth

#11
Quote from: MGebhart on May 22, 2010, 05:49:02 PM

Yes, this is transparent and not just a reflective sphere. If I get a few minutes I'll throw something behind it and render.

Waiting for this because in your exemple render, it really looks like it is only reflecting the ground, as Klas stated. Plus we don't see the darker part (base part) of the sphere, so I did think it wasn't transparent at all but only reflecting light fooling us into beleiving it is glass :) I really wait for next exemple with an object behind the sphere ! my second question is : how does this shader react with another sun orientation (I personnaly had some big surprise just changing the light) and on another kind of object ?
though it is really nice looking ^^

Quote from: jritchie777 on May 22, 2010, 08:03:58 PM

You be the judge, but I like the reflective shader, thanks for sharing your work with us.  This will also help with some of my renders that I use water shaders for other effects, now I will use the reflective shader instead!


no transparancy on your reflective shader. it doesn't match the water shader on your exemple render. ;)

dandelO

I think that Seth and Klas are right, I've tried exhaustively to create transparency with a reflective shader, no cigar.

I remember Walli posting an example here before with transparency from a reflective shader, I tried matching his settings on my own, still nothing. I put it down to Walli using a different unreleased version of Terragen that the general public did not have. After the new release, though, I tried again and had the same negative results.

I can easily create a fake reflective transparency effect, like this appears to be. I will try this in an imported model instead of a native TG sphere to remove 'double sided surface' manually but, since a TG sphere is single sided anyway, I'm not sure it'll make much difference.

I'm probably missing something really simple, if you have indeed made transparency here, Marc. ???

dandelO

#13
Also.

Reflection samples will have no effect on the surface, until you start adding 'reflection softness'. You could use a sample of '0' for the same result as your '16'.
Unless you enable softness, samples don't matter.

EDIT:

Tried your settings, with the exception of softness = 0.1 and samples = 32. Also, a refraction index of 1.15 returns a black surface reflection. Here, IOR is 8.
There are 3 spheres here, one is behind the centre sphere, it isn't visible.
0.5 render detail - 4 minutes. What are we missing?

[attachimg=#]

dandelO

And here's Walli's post from before... http://forums.planetside.co.uk/index.php?topic=8031.msg85835#msg85835

I still cannot match this on my own with a reflective shader. A water shader, no problem.
Confused. ???