Pearlescence - has anyone simulated it in DS?

richardandtracy

One thing I see on a daily basis with my fountain pens is a lovely sub surface reflectivity, with the reflections from within the plastic appearing to change depth and intensity dependant on the angle of view. I don't think I have seen this in DS. Does anyone know different? I do hope so.

If anyone has seen it, do you have any idea how it was done? I suspect the dual lobe shader would be ideal, but my experiments so far have been total failures. I have tried putting the diffuse texture in the lobe 1 and lobe 2 textures. To no effect. The surface still seemed dead and lifeless

I look forward to suggestions. Regards, Richard.

Hylas

These are from a Allen Art freebie set: https://sharecg.com/v/95893/gallery/21/DAZ-Studio/Iray-Jewelry-Shaders

They do it with Top Coat and Metallic Flakes.

richardandtracy

Hmm. Not entirely the sort of thing I am wanting to simulate, but it might be a better place to start than where I am - thanks. The sort of effect I'd like to simulate is similar to the one in this image: https://www.fountainpennetwork.com/forum/uploads/monthly_12_2015/post-115482-0-43129700-1450232683_thumb.jpeg. The material seems to have depth, and the pearlescence Reflects/shines brightly at two different angles. The external surface of the material is flat, but it looks like the surface you see is inside the external surface, even though it's only a transparency effect and possibly internal ior effects between different colour density layers. (I have turned enough of these materials and made enough pens to know how the materials are through their thickness.) Some of these materials have unevenly distributed swirls of mica flakes added to the resin prior to it setting, but others simply use swirls of nearly imiscible liquid resins to get the effects.

IceCrMn

That looks quite a bit like some of the veined marble shaders for iray I've seen.

I got a render cooking right now, so I can't check my library, but I think it was in one of the nvidia vmaterials packages.

richardandtracy

AHH sounds promising. I'd appreciate it if you could look when convenient. It's not urgent - and it's well past my bed time anyway!

Hylas

Looks to me like that's what Metallic Flakes is made for.

IceCrMn

OK, it's the vmaterials v1.7

after you get them installed 

https://sharecg.com/v/96902/browse/21/DAZ-Studio/NVIDIA-vMaterials-1.7.0-Presets

install instructions on the download page

warning HUGE download(almost 2GB)

it will be in Shader Presets>Nvidia vMaterails 1.7.0>AEC>Stone>Marble

Change the colors and play around with the "Color Detail".

Change the "Scale X" , "Scale Y" to adjust the pattern.(See Top White and Black Pen)

Close up they look like the cheap pens with the stickers on them(you can see the tiling in the shader)

So, it's more marble than Pearlescence.

The link Hylas posted for the AllenArt gem shaders looks more pearly, but doesn't have the marbled veins.

Really good shader set.I use it alot.

(See center Pen.Dyed Orchid)

Maybe can use different metallic flake/top coat maps for that?

WendyLuvsCatz

richardandtracy said:

Hmm. Not entirely the sort of thing I am wanting to simulate, but it might be a better place to start than where I am - thanks. The sort of effect I'd like to simulate is similar to the one in this image: https://www.fountainpennetwork.com/forum/uploads/monthly_12_2015/post-115482-0-43129700-1450232683_thumb.jpeg. The material seems to have depth, and the pearlescence Reflects/shines brightly at two different angles. The external surface of the material is flat, but it looks like the surface you see is inside the external surface, even though it's only a transparency effect and possibly internal ior effects between different colour density layers. (I have turned enough of these materials and made enough pens to know how the materials are through their thickness.) Some of these materials have unevenly distributed swirls of mica flakes added to the resin prior to it setting, but others simply use swirls of nearly imiscible liquid resins to get the effects.

sounds rather like parallax which I have been trying to do in various softwares with different levels of success 

 

not tried it in DAZ yet, the video is Twinmotion and the Twinmotion material nodes datasmith imported then duplicated in Unreal Engine where I investigated it further

is using a type of displacement but it doesn't displace in 3D rather the image moves from camera or viewport position according to a depth map like those depth map Facebook images

richardandtracy

I think Wendy's parallax idea is closest to what occurs in reality. The marble material in the white areas does look flat and looks as if you can't see into the material, as if it's only a surface texture. TBH that's not far from the effects I've been getting myself, and no different from what I actually get from turning home cast polyester resin. It's a nice material, but.. The Celluloid/acrylic materials used in some of the best pens ARE difficult to create, so I was expecting nothing else with reproducing the effect. An alternative, I don't really want to contemplate, is modelling in an internal surface so the outer material can be clear and the inner material be contoured to the apparent surface...

WendyLuvsCatz

maybe several geoshell layers with staggered veins and cutout opacity

richardandtracy

That's a much better idea than I have had so far... Much better than modelling an internal surface. I can see I am going to have to brush up my 2d painting skills from their current 'utterly pathetic' standard.

Spacious

You may be able to get what you're looking for by experimenting with bump/normal and top coat.  If you reverse the bump direction on the the top coat layer from the regular bump, and use the top coat thin film setting with a significant thickness dialed in.

Otherwise, two layers of geometry with the outer layer transparent.  I'd use displacement rather than actually modeling the under layer, but...

richardandtracy

Thanks. That gives me several approaches to try. Would be nice for a simple set of shader settings to work.

WendyLuvsCatz

do you have these?

https://www.daz3d.com/pl-semi-precious-iray-shaders

maybe with translucency and refraction bumped up could work with geoshells, I am playing with them now

I found refraction at 50% lets some show through, second one has 2 geoshells and three shaders offset -1 and -2 

it probably could be subtler

the video looks like stuff in a jar 

the ends are a tarnished metal shader by Jenny Greenless meant to contrast the effect

 

 

video

richardandtracy

I don't have that set, and wasn't even aware of it. Good spot, thank you very much and it's now wishlisted. It's close to Christmas, and my wallet is somewhat empty.. Maybe next month. Your video is showing some of the effects seen but not all. The pearlescence can appear to change reflection angle across the cylinder as it turns. If you imagine the reflection occurs at 30 degrees to the camera, at some points it'll be reflecting from the correct position on the outside of the cylinder, then you'll get a flash of reflection somewhere else, as if there is a surface at 30 degrees to the camera within the material that is reflecting back to the camera. As the cylinder rotates further, the reflection can move faster or slower than the cylinder, as if the apparent internal surface has its own contours unrelated to the cylinder surface. It's a really hard thing to describe, but is really attractive. And strangely it was more common in the 1930's when celluloid was more commonly available. Regards, Richard.

nonesuch00

There are these, but even the author admits they are "pearlish" but not Mother of the Pearl shader materials.

Pearlish Iray Shaders | Daz 3D

Personally, I'd like a good set of such shaders including the mother of the pearl effect made on the interior of abalone shells. 

richardandtracy

Thank you all. It appears that the particular effect I'm looking for probably hasn't been simulated yet. There are a few avenues that look promising that I will need to investigate in slow time (ie when I have time), and it's going to take a while to get right, if I ever manage to do so. Regards, Richard.