Open-Source, Scientifically-Accurate Materials Presets

[Thom Blair III]

I would LOVE to have a set of open-source, scientifically-accurate preset materials to choose from so that I don't have to figure out all the physics properties for each substance each time I create a material.

For example, I would love to have presets for: water, gas, glass, metal, stone, clay, fabric, leather, skin, plastic, fire, etc.

Ideally, the physics properties of the presets would be true to life, using the same technical data physicists use.

In the short-term perspective, such accuracy will guarantee the most realistic renderings/simulations.

In the long-term perspective, the accuracy could be of great importance when 3D scanning & printing become more mainstream.

Is there an ongoing move to collect material data from physics labs and make sure the data is formatted in such a way as to be useable by the CGI industry and the 3D scanning/printing industry?

It seems to me such a merger is the inevitable future of CGI, 3D scanning/printing and engineering in general.

I know currently Epic Games, as part of the company’s $100 million Epic MegaGrants program, is awarding the Blender Foundation $1.2 million in cash to further the success of Blender, the free and open source 3D creation suite that supports the full range of tools empowering artists to create 3D graphics, animation, special effects or games.

The Epic MegaGrants initiative is designed to assist game developers, enterprise professionals, media and entertainment creators, students, educators, and tool developers doing outstanding work with Unreal Engine or enhancing open-source capabilities for the 3D graphics community.

Perhaps Adobe, the 3D scanning/printing field, and the engineering fields should begin working with Epic Games and/or Hollywood CGI companies to formulate a roadmap for future integration of all these industries and their respective platforms.

Perhaps material data could be gathered from sources such as:
- national laboratories like Jefferson Lab or Fermilab
- academic institutions like MIT
- engineering platforms like MATLAB

Ideally, I'd love to see kids playing with modeling software on platforms like Hack, people repairing broken products at home via 3D scanning/printing, and high school students producing award-winning Hollywood movies on shoestring budgets in their spare time.

How can I help stimulate/facilitate this vision and merger of industries?

[Thom Blair III]

So, I have found some material databases. If you know of any, please feel free to add them on here. Maybe we can make a suitable database from multiple sources:

1.- ASM Alloy Center
http://www.asminternational.org/portal/site/www/info/aco/
Provides access to worldwide equivalencies for alloys, mechanical, physical and chemical property data, and corrosion characteristics in various environments. Covers: Alloy data sheets, Stress-strain curves, Creep curves, Time-temperature curves, Engineering graphs, Thousands of significant alloy designations. With over 5,000 Alloy Digest Datasheets, the Alloy Center is a flexible and convenient tool for identifying and selecting alloys.
 
2.- Granta CES Selector
https://grantadesign.com/industry/products/ces-selector/
“CES material and process Selectors are used by mechanical engineers, designers, materials specialists, and materials developers to achieve reductions in component cost, enhanced product performance, better design quality, and design innovation” (UK)
 
3.- Materials Design http://www.materialsdesign.com/
“is the leading atomistic simulation software and services company for materials. Help customers across many diverse industries design new materials, predict their properties and generate value through innovation.” (USA)
 
4.- MatWeb http://www.matweb.com/
“This searchable online database of engineering materials and includes data sheets of thermoplastic and thermoset polymers such as ABS, nylon, polycarbonate, polyester, polyethylene and polypropylene; metals such as aluminum, cobalt, copper, lead, magnesium, nickel, steel, superalloys, titanium and zinc alloys; ceramics; plus semiconductors, fibers, and other engineering” (USA)

[Thom Blair III]

Refractive index database:
https://refractiveindex.info

Note: In the "Shelf" section, they have an option for "3D - Selected data for 3D artists":

[Vincent Gault]

hey, you have the base material in substance Designer, that can be helpful for some metals.
indeed that we (or the community) can improve

[Thom Blair III]

Is there some way I can help gather data? Are there specific data types or sets of data that you are looking for?

I don’t own Substance3D, I’m just a big fan of mechanical engineering (like 3D scanning & printing) and realism in CGI.

[Vincent Gault]

One interesting solution would be to create a Substance file in SD, with as much properly set materials as possible.

[Thom Blair III]

Yes, that sounds like a good idea.

One thing I had been thinking is that if an open source database of material properties is online, each 3D modeling program (Substance3D, Autodesk, Blender, Unity, etc.) could have an interface / add-on that allows people to browse the database and select (and/or save locally) data presets as they are working. That way users wouldn't have to have unnecessary data on their computer if they didn't want it, but could get it real-time as they are modeling.

One thing many groups say is their data is not formatted for 3D modeling, which is to be expected.

So, I was thinking any modeling software accessing the database would need an add-on/interface translating the data into a format appropriate for their software.

[Vincent Gault]

could be great, indeed but a bit beyond our scope for now

[Thom Blair III]

Ok, sounds good.

[Thom Blair III]

Oh my gosh! I just saw an ad for the functionality I was hoping 3D design software could incorporate! It's called COMSOL:
https://comsol.com/comsol-multiphysics
It's SO cool! Perfect for 3D printing & super realistic animations. Check it out!

[Vincent Gault]

Oh my gosh! I just saw an ad for the functionality I was hoping 3D design software could incorporate! It's called COMSOL:
https://comsol.com/comsol-multiphysics
It's SO cool! Perfect for 3D printing & super realistic animations. Check it out!

Once again, I can thhe the interest, but it's really out of SD scope

[Eggfruit]

It may be out of the scope for allego, but it's still interesting for the community to collect this kind of data.

As you may imagine, surface measurements are mostly important in texturing.

Surface color information is split into (specular) reflectance and diffuse color. Reflectance is the amount and color of light reflected directly at the surface, while diffuse is light that enters the material and comes back out.
The reflectance color is primarily important for metals. Most non-metals share roughly the same reflectance value, but outliers are also interesting. Reflectance is directly related to ior. But ior is usually found as a single value, which gives no indication of color. Finding reflectance or ior values in rgb color would be a very interesting one. Some full spectra can be found, like in the link you profided, but it's very hard for artists to translate this to rgb.

(Micro-)surface roughness (or glossiness) is another important one. In real life roughness is a result of microscopic geometry, but in cg a roughness value is used to simulate this. I'm not sure how this can be accurately measured and translated to a usable roughness value though.

Roughness is not material dependant per-se as every material can be polished to a shine or roughed up to a certain extend. But common standards or median values can often be found. A layer of latex paint on a flat surface will usually result in the same roughness for instance.

Check this out for a bit more information about these values: https://marmoset.co/posts/basic-theory-of-physically-based-rendering/
Allegorithmics own guides on physically based rendering, going into more detail and examples of use-cases: https://www.substance3d.com/pbr-guide
And a slightly more technical take, with some charts of some known values: https://seblagarde.wordpress.com/2011/08/17/feeding-a-physical-based-lighting-mode/

[Vincent Gault]

This is definitely important and interesting.