A multipurpose technology used by many factions, Solid Volumetrics are an advancement in standard Volumetric Display technology which allows for the production of tangible images and objects through the use of specialized projector systems.
Though volumetrics in general are widespread in use, solid volumetric systems are far more uncommon and sometimes even rare in the Kikyo sector. In comparison to standard volumetric systems, which may be highly compact, these often require relatively large, complex projectors which are several times the size of intangible volumetric systems. This large size limits their use, but in addition, the solid volumetric projectors are more complex and require much larger quantities of energy to sustain them. As a result, these are most often stationary in nature, hidden or blended into the background to keep them concealed at whatever buildings or facilities they are employed at. Typically, these are used to create photo-realistic, solid objects for a variety of purposes, primarily as an interface through which AIs or other individuals may interact with others, and even training systems for various applications.
Throughout history, volumetrics, often referred to as holography in the distant past, have been used extensively. As the technology advanced, its core principals and end results remained relatively the same, though new methods of achieving them arose. With these changes in the technology, volumetrics advanced to the next level - it was discovered how to make their projections tangible, but in most circumstances, the feature comes at a tradeoff. Most Solid Volumetric projector systems are not only larger, but more costly and with a higher energy consumption. As a result, the systems were mainly used in stationary roles.
Standard volumetric designs use specialized projectors to generate and control the behavior of visible light. Meanwhile, solid volumetric systems focus on not only this, but also direct control over various particles to simulate the presence of matter. Atmosphere or cold plasma used specifically for the purpose is compressed and held in a thin layer, the particles themselves made to be 'stationary' in place relative to one another. This creates the illusion of solidity when physically contacted, as the particles do not noticeably move when touched. At the same time as this is done, the visual appearances are handled by the more standard extensions of the volumetrics.
As many factions use similar or closely related technology, various methodologies exist with which to generate same or similar results. The most common method of producing solid volumetrics would be the usage of powerful but closely controlled and confined electromagnetic fields. As an example of different methodology and implementation, the Yamatai Star Empire often uses airborne femtomachines in their solid volumetric systems and some forcefield systems as well. These form vertexes from which edges can be drawn between individual units, creating trillions of simple shapes such as squares, triangles and so forth, which would all come together to generate a photo-realistic projection.
In general, more advanced systems may even vary the behavior of their particle fields, giving accurate simulations of various textures, elasticity, and so forth. Lower end systems may be unable to accurately simulate elements such as iridescence or sub-surface scattering. The inability to do this often gives such projections a 'flat' or unnatural look which fittingly falls into what is known as the 'Uncanny Valley', where a sense of 'wrongness' may be noticed by viewers. Higher end systems may compensate for such deficiencies in the volumetric object's characteristics by using sensors observing the surrounding light sources and then directly simulating what would occur if the object where real. The very highest systems instead directly make the volumetric field have the same light characteristics as actual objects - these are often the largest and most expensive systems, used in upscale theater or other similar applications.
Despite any differences, the vast majority of systems share a certain trait; bad weather such as a rainy downpour or snowstorm will adversely affect the quality of the Solid Volumetric projection.
An entirely different family of technology, Hard Light can do many of the same things solid volumetrics do but follows an entirely different methodology: That of creating real matter using a nucleus of photons, not one of protons and neutrons. This nucleus can act as a simple transistor meaning hard-light can be programmed to act in different ways, even altering the electron shell arrangement and its behavior (and therefor its atomic properties) of specific components. In addition, with a nucleus of photons (which are almost massless), hard light is incredibly light and by default transparent.
While hard light specifically is unaffected by weather conditions, changes in lighting may reveal transparent hard light which is present. In addition, while a hard-light object is permanent (though prone to damage as conventional matter is, needing a projector to repair it and not just machining or tooling), maintaining, forming or repairing hard-light is incredibly energy intensive.
These are notes from Fred, prior to the article being approved; they've been left here as a resource allowing players to understand the thought process and details of what went into this article. This is particularly important, as solid volumetrics have been in the setting for a long time, but have not had an article until now.