[WIP] Serpent Vase

rexo12

Hello. Been a very long time since I've posted here. Work, uni (and life...) left me with zero time to do any 3D art. This is a small project just to prove to myself I can still finish something!

This is a vase by Tiffany Furnaces i saw (and was infatuated with) in the NY Met. during a trip I took earlier this year.

Above is the single photo I took just to remind myself that it existed for later, before I discovered that there are very few photos of this on the internet, and none of them of a high quality.

This is the current state of my high poly. The snake skin was an incredible pain to work out.

I'm not super happy with the state of the snake heads. I've spent a lot of time mucking around with them, and I have kind of got in too deep to really work out what's wrong with them. Some feedback on these would be greatly appreciated.

The plan is to make this an opportunity to play around with Unreal's Substrate framework properly, which I'm really looking forward to, having spent all year doing my thesis on the engineering side of material layering.

Feedback welcome please!

Eric Chadwick

I think it might help to study snake anatomy, and incorporate that into your sculpt. They tend to have really distinctive, and frankly really beautiful, skull & muscle shapes which you could exaggerate a little. Since they are a focal point of interest.

Fabi_G

This looks like a cool project
Are the snakes posed using curve deformers? I think putting a snake in a more neutral pose would make it easier to do overpaints and adjustments it based on anatomy references. Some distinction between belly and top might improve the look further. Keep it up!

sacboi

Could perhaps subtllely emphasize anatomical features of the skull? 

Hopefully without compromising your references stylistic aesthetic because I share Eric's sentiment, they're indeed beguiling creatures which from one brief encounter in the aussie bush, can most definitly attest too.

rexo12

Appreciate the replies.

I think maybe what I'm missing is the jaw muscles. I also think the start of the neck (erm, body?) is too far away from the end of the mouth, looking at refs the mouth almost hinges right at that point.

The piece itself is much more square than this however.

He also seems to be a bit lumpy at the moment, which i've been trying to refine out but don't seem to be getting anywhere fast. I've unfortunately not set myself up for success with respect to underbelly details, I like the idea but i think I'd need to merge the body and head again.

rexo12

Took a break from the sculpting since I have spent too much time on it. Did some bake tests, and am working on prototyping the glass material. My references have very wide and even specular sources which makes the glass appear much more diffuse than it really is. I did find a single additional image that has better detail:

As well as some broader references for Favrile glass in general.

Annoyingly hard to find material of the glass in motion, everything is just panning across still images which is not useful for understanding how it responds to light. This vase seems to be a special case of Favrile glass too, being much more opaque, and separating the iridescence from the base material is proving to be difficult due to their similarity.

Iridescence experiments in-engine. This is using the Thin-Film helper to modulate the F0/F90 by the surface thickness & IOR (and i suspect also view direction...) Obviously wildly off at the moment. I have been using this article as a reference: https://www.getty.edu/conservation/publications_resources/pdf_publications/color_science.html (chapter on pearlescence/iridescence), alongside Epic's substrate content examples.

Also sketching this out in Substance. The workflow for this is going to be a bit tricky, since there isn't a one-to-one mapping from any of Substance's shading models to the Substrate parameterisation, and there's possibly layers involved too (although I expect I can do without explicit layering). My plan is to do as much as I can with masks and rebuild the material from those masks in the shader graph, rather than exporting parameter textures.

The marbling needs to be more fluid, but also more uniform, if that makes sense? The marbling stays broadly horizontal, particularly on the upper parts of the vase, and the swirls seem to repeat with the ribs of the vase.

Towards the bottom of the vase the swirls appear to 'bulge', too. Finding this balance is probably what is throwing off the rest of the marbling. To generate the marbling I am warping horizontal stripes by some curl noise, which will broadly imitate the actual action that creates this effect: swirling the blown glass in some acid mixture (or so I think, anyway). The vase also seems to have this view-facing purple tint to it that I am unable to really replicate so far.

rexo12

Vase is most of the way there now I think, still need to tweak materials and such. I'm still not sure i've captured the iridescence properly, but without being able to go look at it again (being on the other side of the world) I may just have to settle.

Been blocking out a scene for it too. I like the bell-jar as an idea but it obscures the focal piece (the vase) too much and the mirror version's composition reads much better. Doing both would be too unfocused. Want to carry the flies forward from the bell-jar somehow though. Also thinking of projecting some kind of false reflection in the mirror.

rexo12

Been through several reworks of this. I did some scanning of some native plants near me and used that to rework the central plant, which I think has a much more interesting silhouette now. Also scanned some bits and bobs to populate the scene with secondary and tertiary forms. I think I'm about 80% happy with this now, the right side still feels too empty and I think just a couple more detail elements would help push it to where I'm satisfied, just struggling to think of things that have some sort of symbolic meaning, won't dominate the scene, and also not take another 4 weeks to model.

sacboi

Oh this is absolutely gorgeous, beautifully crafted!

And yes quite cerebral, possibly a composition/scene gracing some antiquarian's abode so maybe add a book?

Edit:

I'm curious about a couple things I've noticed

- In the mirror's reflection, is that figure you?

- Also those black specks seem to be flies or bugs trapped under the glass bell clochet?

Again well done.

Celosia

That's an awesome vase, I love it!

About the shader, I'm late to the game but I might be able to help. Disclaimer: I'm an illustrator, not a 3D artist.

I put something together in Blender, it got plenty room for improvement but I think it's enough to explain what and why. Let me know if you want the file to play with it.



The key to the shader is a good diffuse you can hue shift with fresnel. I've not touched Unreal in years but it must have fresnel since fresnel is so basic, and I know it has something similar to incoming because I recall creating a hue shifting "eyes in the dark" shader once.

This is what I'm doing in Blender. Diffuse in, use fresnel to shift both hue and saturation (more on why both below). The incoming is not vital, it just adds a layer of interactivity, an extra hue shift by texture when you move around the object that isn't 1:1 to the fresnel.



This is a PBR shader + fresnel. Here are the maps with extra contrast so they're visible and saturation in case of the normal (which is a converted bump map). Only the diffuse is as is.

Diffuse, roughness, metallic, normal, fresnel-controlled hue, fresnel-controlled saturation. They'd need adjustment for Unreal because last time I checked it treats some things differently from Blender.



They're all procedural, using noise, wave and normal/gradient textures.

I don't know much about this kind of glass at all and don't have the time to research, so I took the educated guess that the iridescence isn't down to pigment alone, it's structural like humming birds' feathers. It makes the effect a good candidate for fulling the role of micro detail in the texture. I made the glitter fairly large due the distance we expect the vase to be viewed.

Added to that there seems to be a small, tactile-only wave pattern in the vase, so I layered that and the glitter in the normal and other textures.

You can see metallic and roughness differ slightly, they're not the same texture in different grayscale values although they were generated using the exact same noises. That's because using the same texture can make something look artificial, not in the man-made sense but in the unnatural-looking sense. Materials have variation in density, components mixing, etc, so even the same material straight from the factory will have subtle variations in roughness and reflectivity and color. Add the wear of light exposure and age, even little age, and you won't have something that maps out the the exact same textures. Sometimes you can get away with it, but if you can, put a little extra effort and vary them a bit.

When creating textures it's also interesting to experiment and do the opposite of what you'd do normally. Crevices usually are darker, right? What if you make them lighter? You'll be surprised by how well stepping out of what you think it should be can work.

Finally, and that's the only thing I'm really qualified to talk about: Hue x saturation

Color is relative. My favourite color is gray, not because it's gray, but because it's kinda... any color you wish. Put gray by a cold color and it'll look warm, reading as red or orange, place it by a warm color and it'll turn blue or green. It's magic.

Meaning you can shift the perception of a hue by decreasing the saturation. It's subtler, it makes the color you're contrasting against pop more, it's a strategy I use in painting all the time because it works and it's wonderful. When everything is saturated nothing is, but if you pick the saturation levels carefully then your work will have more impact. In the context of that texture I absolutely don't need a warm tone as saturated as the base color for the waves or fresnel, thus I'm not relying on changing the hue alone, I'm delegating some of the temperature shifting to the saturation to make the color warmer without being overwhelming.

And that's it. I hope this helps!

rexo12

@sacboi
Thank you! To answer your questions:
1. Maybe..
2. They are flies! Need to do another pass on them as they still have a uniform material. 

@Celosia
Hey, really appreciate the detailed feedback. There's some very interesting ideas there that I'm excited to try, such as the inversion of expectation. I struggle with not thinking like an engineer and more like an artist sometimes so these little mantras are very helpful for me.

You are spot on in your assessment of the material. I'm using the new substrate framework for this, so I have a lot of freedom to vary the diffuse + specular response. I was using a thin film utility to model the hue shift by simulating the IOR & thickness of the etch layers, but maybe I should just author it directly. Introducing some glints is also a good idea.

There were a few contradictions in my understanding of the surface that I was having trouble reconciling:
- up close, the glass has a lot of macro geometric detail due to the acid etching process used in manufacturing, and is actually quite rough. However, at further distances this becomes a visually smooth and glossy surface.
- There's a view dependence to the specular that is very hard to pin down. You'll see in my references that while the highlights still appear to be mostly white, it's almost as though the colour of the glass shifts from a sort of washed out purple to a light blue or gold depending on where the viewer is. I'm modelling this with a custom specular profile at present, so I can preserve the whiter peaks while introducing that broader view shift, but it still feels a bit off.