We first introduced X-Rite Pantone’s Total Appearance Capture technology some weeks ago. This technology allows a full, high-quality digital scanning and characterization of material surfaces for use in high-end computer-aided design, with the goal of creating photorealistic renderings in an easy and predictable way.
The Total Appearance Capture technology will be publicly revealed by X-Rite during the Press Days of the Geneva International Motor Show on 5 – 6 March 2013, with session scheduled at 9:00 – 11:00 – 14:00 – 16:00 – 18:00 on both days.
Recently we had the opportunity to discuss some of features of this technology with X-Rite researchers – you can read this exclusive interview below. You can also find more information visiting X-Rite’s website.
What is, in your opinion, the most important benefit that this technology can bring to the industry?
Having a predictable and system-independent representation of material appearance with true WYSIWYG (“What You See Is What You Get”).
Today’s material representations generally cannot be transferred between systems, require lots of manual tweaking or even shader programming, are heavily dependent on lighting and don’t capture all aspects of material appearance.
What was the most complex technical challenge you had to face when trying to simulate the complex behavior of materials?
We are not simulating – that’s a different topic (which can be combined with our approach). We essentially measure the reflectance behaviour of the material so that this behaviour can be recreated during rendering.
One of the main challenges we were facing is the sheer amount of data that is acquired during a TAC scan and how to compress that into something that a standard rendering package can easily deal with; of course we had to develop methods that do this without sacrificing fidelity.
Are the generated materials modifiable in a post-processing workflow (for adjusting certain parameters, or creating a library of similar material presets)?
In general, the need to modify materials is greatly reduced and in many applications even eliminated altogether when you use TAC materials; this is a direct consequence of the TAC method – it just captures the full appearance of a surface.
To some extent, however, it is modifiable, since some customers want to achieve a certain look or create something new based on a measured material.
Rendering software has evolved a lot in the latest years. From the designer’s perspective, what are the main practical benefits of using these physically-accurate materials – ease of setup, final quality, etc.?
First of all, for many designers, the TAC materials will be the first to fully exploit their rendering system’s capabilities. Rendering systems have come a long way and are now extremely powerful, but the material definition is usually the weakest link in the chain. This is where the designer will see a quantum leap in realism and productivity.
The designer can now deal with materials of virtually any complexity (3D-structure, arbitrary anisotropic reflectance behaviour, mixture of arbitrary materials) without requiring any setup despite selecting the file and adjusting (scaling) texture coordinates.
You are currently working for supporting a wide range of rendering engines. Are you just interested in CAD-oriented packages or are you also working to support visualization-oriented 3D software?
Our materials are actually used in both worlds. As an example, we support PI-VR’s VRED, which is a visualization-oriented rendering package.
Does this technology require an increased computational power? What are – generally speaking – the differences in terms of rendering times compared to the various current rendering engines (both biased and unbiased)?
Compared to a standard shader (diffuse/specular texture, normal map) and depending on the representation and desired fidelity you can expect the shaders to be somewhat slower.
Considering that the measured representation has integrated all the complex light-transport mechanisms (shadowing, inter-reflections, scattering) that make a material look real, customers seem to find this acceptable. The alternative would be to model the micro- and meso-geometry of the material and performing all the light transport computations during rendering…
Will you provide – or are you evaluating the possibility of providing – a way for designers to “create” their own materials by specifying their physical properties?
For specific material types like paint and textiles, yes. X-Rite has a long history in “formulation”, a key component of formulation is the math to go back and forth between the physical properties of a material and its appearance.
Are you targeting other markets besides the industrial design field (Visualization for Movies and games, Arch Vis, VFX)?
Yes, we do. The TAC method and material model is very versatile – we achieve unprecedented realism and accuracy over a very wide range of materials. Besides industrial design, we are targeting product design in general, the movie industry, architecture, and advertisement.
When can we expect this technology to become available for the material producers and for the final users (visualization designers)?
This is either available already or will be available in 2013.
A question about the business model: are you planning to spread the costs only among the manufacturers to maximize the adoption rate, or also among the final 3D users?
We follow both ways: in one case, the end users have their materials scanned and therefore pay for it per scan. In another case, material manufacturers come to X-Rite and have their materials scanned; they then provide those to their customers, e.g. as part of a combined physical-virtual material sample set or catalog.
Finally, a couple of more specific technical questions.
How are texture patterns handled – do they use bitmap textures, procedural textures or other system?
The texture is part of the measured data. In fact the representation does not contain just a single texture but thousands of textures that are extracted from the compressed representation during rendering. Internally, special algorithms are used to reduce tiling or to hide seams.
Is the UV mapping of an object still required in case of complex geometry and patterns?
Yes, UV-mapping is required.
Do these materials require a particular rendering setup? (Global Illumination, CG lights, etc.)
We recommend to use the materials with GI because only then one can really appreciate their full beauty and realism. Nevertheless, real-time rendering, e.g. using OpenGL is also supported.
(Image Courtesy: X-Rite for Car Body Design)