Author Topic: Sub surface scattering again...  (Read 41642 times)

Offline Hannes

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Re: Sub surface scattering again...
« Reply #195 on: December 18, 2014, 08:11:32 AM »
Beer head! That sounds good. Thank you, Otakar. ;D ;D ;D
One last beer!!
I improved the textures for the beer head and gave it a slightly warmer colour.
Enough beer.
For now...

However, as I wrote in the first beer post, rendering the beer body inside the glass makes it black. So I unchecked "visible to other rays". So far so good, the beer renders correctly. But somehow it looks different. Plus when I put the glass onto a reflective surface, everything is reflected but the glass, which is weird. Is there any other way to render this correctly without unchecking the "visible..."-thing? Remember, I tried all combinations of object/shader doublesided on or off plus cast shadows on or off for each object.
You can render thin single sided objects inside other thin single sided objects when they both have a glass shader assigned to, the TG native sphere for example, but once the objects have solid walls, it doesn't work anymore. So, any ideas, or is it just impossible at the moment?

Offline Hannes

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Re: Sub surface scattering again...
« Reply #196 on: December 18, 2014, 12:24:34 PM »
Too much alcohol...
Here's something healthy. This time I used a water shader with a warm white colour in the Volume 1 colour tab instead of a fake SSS shader.
I'm a bit confused that I could render a solid body of milk inside a solid glass this time. There are some faces that are darker, which seems to be an intersection issue. So I tried to make the milk body slightly smaller, but then the milk got darker and darker. Unchecking "Visible to other rays" of the glass object makes the milk bright again, but then the glass is black!

Think I'll cry a bit now...

Offline bobbystahr

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Re: Sub surface scattering again...
« Reply #197 on: December 18, 2014, 01:17:28 PM »
Great milk and interesting problem. Dunno why that'd happen.
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

Offline j meyer

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Re: Sub surface scattering again...
« Reply #198 on: December 18, 2014, 02:28:01 PM »
Mind sharing the glass and milk objects so we can
try with the same or at least showing the wireframes?
Do the objects intersect?

Offline Hannes

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Re: Sub surface scattering again...
« Reply #199 on: December 18, 2014, 03:43:15 PM »
Ok, I guess it shouldn't be a problem to share the glass. It's a free object from here:
http://archive3d.net/?a=download&id=bfab47f8#
Credits go to the maker, whoever he or she is. It's uploaded by Katrin Wagner, so if it's been her, thanks a lot!

I then created the milk body by adding a cylinder and a boolean subtraction operation. The upper surface of the milk is modified so that the rim is slightly higher than the rest.

I tried to subdivide the glass and created a new milk body, thinking that it might work better when it's more detailed, but it was even worse, so here is the original file. It works except those few faces that are kind of dark.

Btw I posted the problem in the Glass shader thread, that Matt had started.

Offline j meyer

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Re: Sub surface scattering again...
« Reply #200 on: December 18, 2014, 05:21:06 PM »
As for the transparency thing I've no idea so far,but the
artefacts you get might be due to bad geometry.
At the bottom and around the top rim of the milk there is some
really nasty geometry.Maybe caused by that boolean operation
you mentioned.Overlapping faces and edges.

Offline Hannes

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Re: Sub surface scattering again...
« Reply #201 on: December 19, 2014, 07:20:48 AM »
I can't stop.  ;)
Cartoon cheese.
I know the holes are a bit faceted, the spheres I used for the boolean operation weren't high res enough. It's just a quick shot for fun.

Offline j meyer

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Re: Sub surface scattering again...
« Reply #202 on: December 19, 2014, 02:04:05 PM »
Played with your tgd last night and what I saw reminds me
of some transparency peculiarities that came up when I tested
the render layers/elements.
http://www.planetside.co.uk/forums/index.php/topic,18176.msg176267.html#msg176267
I assume these are related,but I might be totally wrong.

Keep experimenting!

Offline bobbystahr

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Re: Sub surface scattering again...
« Reply #203 on: December 19, 2014, 03:27:19 PM »
I can't stop.  ;)
Cartoon cheese.
I know the holes are a bit faceted, the spheres I used for the boolean operation weren't high res enough. It's just a quick shot for fun.

Hee hee hee, cool image tho
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

Offline Matt

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Re: Sub surface scattering again...
« Reply #204 on: December 21, 2014, 10:34:52 PM »
Why in all that is holy would Terragen assume anything is in a arcane format like SRGB for CRT monitors? lol It should only use Native RGB/CMYK for plasma/lcd now. You'd think CMYK would work best considering the whole gamut is a natural tone set from the 'real world' and would probably work best for shading such a 'real world' image.

Because most 8-bit images, from most sources, are intended to be interpreted as sRGB. Although it's true that most monitors do a bad job of approximating sRGB.

What is "Native RGB?" Something that is system-dependent?

There is no reason to invoke CMYK when interpreting an image that is encoded with RGB channels, so I don't know what you mean there.

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Also sRGB incorperates both linear, and non-linear gamma corrections leaving you with a adjustment o 2.3 at the end, not 2.2.

Gamma 2.2 is only an approximation to sRGB; I know that it's not exactly the same. However, for most rendering needs it doesn't need to be exactly right. If the final render is gamma corrected by 2.2 and the incoming texture map is corrected by 1/2.2 then the result will be the same, assuming constant lighting and no atmosphere. The same would be true if you used sRGB for both the input and output instead of gamma 2.2, and the lighting would be closer to a true linear workflow (assuming an sRGB source and output display of course), but it's not a big difference in most cases. I think the subtle difference usually gets lost quickly in any colour correction you might want to do to the final image. But I would like to experiment with this some day to really understand how big the difference is.

In the image map shader you can change the gamma correction, but in the Default Shader it (currently) assumes the default of 2.2. If you need more control you can use an image map shader in place of the default shader's built-in image handling.

Quote
Could explain a lot of the anomalies in TG with it.

Since we're being very specific here, what anomalies are you referring to?

Matt
« Last Edit: December 21, 2014, 10:42:02 PM by Matt »
Just because milk is white doesn't mean that clouds are made of milk.

Offline Seth

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Re: Sub surface scattering again...
« Reply #205 on: December 23, 2014, 11:47:54 AM »
That's an awesome Thread !!!

Offline inkydigit

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Re: Sub surface scattering again...
« Reply #206 on: December 26, 2014, 10:53:48 AM »
I echo Seth.... Awesome thread, beer and cheese! Outstanding stuff here!
:)))
J

Offline bobbystahr

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Re: Sub surface scattering again...
« Reply #207 on: December 26, 2014, 01:18:13 PM »
I echo Seth.... Awesome thread, beer and cheese! Outstanding stuff here!
:)))
J

Don't forget the milk...never forget the milk....hee hee hee
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

 

anything