Why these bodies matter
Somaesthetics is the lens that keeps this inquiry grounded. If embodied experience is the medium through which perception, action, and self-presentation happen, then avatar design is never only visual. It reorganizes the felt edge of the body: where the body begins, how it meets the world, and what kinds of relation become possible (Shusterman; Hook et al.).
Weakly bounded bodies matter because they let that edge soften without losing bodily coherence. Across animation theory, media history, XR design, and pain translation, the body can glow, diffuse, swarm, or become collective while still reading as a body when grouping cues, motion, and response remain strong enough to bind it (Wagemans et al.; Johansson; dos Anjos and Pereira; Glowacki).
Once representation changes conduct and self-perception, boundary softness stops being a mood and becomes a design variable. The question is not how strange an avatar can look. The question is what kinds of boundary change alter agency, trust, and social relation without collapsing into noise (Yee and Bailenson; Desnoyers-Stewart et al.; Glowacki et al.).
This essay follows that claim across media history, XR precedent, pseudo-haptic materiality, and pain translation. The through-line is intentionally narrow: bodies do not need sealed surfaces to be experientially real, but they do need coherence.
How transformation stays legible
The core problem can be stated simply: how far can a body transform without ceasing to be experienced as a body? The answer depends on scaffolding. Bodies can lose surface closure and still remain present when grouping cues, motion signatures, and recurrent structure continue to bind the image into something the viewer can inhabit or recognize (Wagemans et al.; Johansson; Richards et al.).
That shifts the problem toward a more useful design rule: do not ask softness to do everything. Keep at least one stable carrier of identity, such as a motion signature, density core, rhythm, or contingent response pattern, so the body's periphery can blur without turning the whole figure into noise. Weakly bounded bodies are not a decorative exception to embodiment research. They are an alternative way of staging embodiment itself (dos Anjos and Pereira; Reeves; Reynolds; Yee and Bailenson).
This is also where the craft sources become unusually useful. Gilland's rule is that stylized effects stay believable when they follow observed forces, preserve an underlying energy, and fit the larger world around them. Bernal and Maes push a comparable point from social VR: expressive fur and particle avatars become relatable not by approaching ordinary anatomy but by making affect and mannerism legible through transformation (Gilland 2009; Gilland 2012; Bernal and Maes).
Historical and conceptual lineage
The most useful historical anchor remains the Eisenstein line around plasmaticness. There, changeable form is not treated as a gimmick but as a refusal of ossification: a body or figure can stretch, melt, assume another contour, and still retain the charge of living form. Abraham Geil helps connect that primary line to a contemporary vocabulary of unstable mimetic identity, while Kristen Whissel shows how digital crowds, morphs, and many-part bodies in later cinema become meaning-bearing structures rather than empty spectacle (Eisenstein; Geil; Whissel).
But that line does not begin with animation alone. Before cinema, phantasmagoria shows used magic lanterns, darkness, smoke, hidden apparatus, and moving projections to make ghosts enlarge, recede, and hover in shared space. Pepper's Ghost translated a related logic into reflective stage illusion, placing apparitions alongside live performers without giving them a solid body. What matters here is that weakly bounded bodies were historically staged as controllable optical events: bodies of light, reflection, concealment, and timed appearance rather than sealed anatomy (Gunning; Owens; Science Museum Group; Royal Collection Trust).
Nineteenth-century spiritualism pushes that grammar further. Owens shows how the seance became a communication scene shaped by telegraphy, table-rapping, photography, and staged expectation, while Simone Natale traces how spirit photographs, stage exposures, magic-lantern entertainments, and superimposition effects feed directly into the visual logic of trick film and early cinema. In that history, ghost images keep wavering between evidence and spectacle, belief and demonstration, stillness and motion (Owens; Natale).
Wilson adds the occult-modernist layer that matters most here. Her account of theosophy, subtle metamorphosis, and ectoplasm shows a repeated effort to render invisible feeling, vibration, and agency as colored clouds, radiating figures, extruded matter, and partially formed bodies. Besant and Leadbeater's Thought-Forms makes that image vocabulary especially explicit by treating thought and emotion as visible form built from color, rhythm, and subtle matter. The value of this archive is not doctrinal. It supplies a historical picture-language for bodies that emanate, protrude, veil, or cohere without hard closure (Wilson; Besant and Leadbeater).
Popular science-fiction television carries the same problem into a mass-media design vocabulary. Star Trek's transporter made body-to-energy conversion into a repeatable visual grammar of glitter, dissolve, and rematerialization, while the franchise's non-corporeal species archive gathered a broader family of clouds, energy beings, host-dependent presences, and patterned light forms. The Zetarians are the clearest fit for this project: a once-corporeal population continuing as a pattern of lights and non-corporeal energy, seeking a compatible humanoid body through which to live again. These references are not the theoretical core of the site, but they are a useful mainstream archive of semi-corporeal body design (ASC Staff; Memory Alpha; Memory Alpha Zetarian).
The wider cluster is worth keeping distinct. The Douwd add disguise, false surroundings, and luminous humanoid dematerialization. Onaya contributes the flowing-and-diaphanous seducer who crosses between corporeal and energetic form. Ronin adds a host-dependent mist that needs an external anchor for cohesion. The Pahvans contribute clouds of glowing blue particles that are inseparable from the larger environment, while the Companion offers a gaseous yellow-orange-red cloud whose relation to the humanoid is intimate rather than merely spectral. Taken together, they show several different mainstream solutions to semi-corporeality: shimmer, humanoid-light, swarm, mist, ambient particle field, and sentient cloud (Douwd; Onaya; Ronin; Pahvan; Companion).
Set beside Bukatman and Whissel, that broader media history stops spectral language from collapsing into a vague mood word. Apparition, ectoplasm, thought-form, swarm, and digital multitude each name different ways a body can become active, relational, and materially persuasive without returning to a fixed shell (Bukatman; Whissel; Wilson; Owens).
What makes this lineage especially useful for current design is that it never really separates appearance from staging. Across phantasmagoria, seance, trick film, theosophical diagrams, and XR, transformation is not only a way something looks. It is a way something moves, phases in, changes state, crosses thresholds, or enters relation. That is why the historical part of the archive matters to the contemporary one: it gives a language for non-solid bodies that are active, expressive, and legible instead of merely decorative (Gunning; Wilson; Liedgren et al.).
Contemporary XR precedents
XR research matters here because it demonstrates that this body logic is not just a theoretical curiosity. Richards and colleagues already showed that presence can be built through spectral embodiment. dos Anjos and Pereira make the question even clearer in contemporary terms by treating abstraction, mesh representation, and point-cloud representation as explicit avatar variables in their own right (Richards et al.; dos Anjos and Pereira).
Danceroom Spectroscopy is a crucial bridge inside that XR line because it turns physics simulation into an embodied encounter rather than a background effect. The participant does not step into a sealed character shell so much as into a responsive field of particles, forces, and feedback. That matters here because it shows that bodily intelligibility can be carried by physically legible interaction before it is carried by anatomical likeness. Set beside the older optical line, it also reads as an updated way of making invisible forces visible and socially graspable (Mitchell et al.; Gunning; Besant and Leadbeater).
The Desnoyers-Stewart sequence makes the particle-body line especially concrete. Transcending Projection begins with point clouds and particle emission tied to mirror identification in shared space. Transcending the Virtual Mirror Stage argues more directly that mixed-reality mirrors can make radically abstract bodies feel ownable. Body RemiXer turns that logic toward intercorporeality through particle auras, touch exchange, and abstract body swapping, while Star-Stuff carries it into constellation bodies that connect strangers through cosmic form (Desnoyers-Stewart; Desnoyers-Stewart, Smith, and Riecke; Desnoyers-Stewart et al. 2020; Desnoyers-Stewart 2022).
The more recent XR cluster sharpens that general point into several distinct precedents. Glowacki's Isness work shows how luminous, weakly representational bodies can be staged as intentional experiences of connectedness, coalescence, and altered self-other relation rather than as visual novelties. Desnoyers-Stewart's ETC gives a different but complementary answer: abstract aura-like bodies can become interaction grammars for touch, timing, and felt social relation at a distance (Glowacki et al.; Glowacki; Desnoyers-Stewart et al.).
The pseudo-haptics literature clarifies why these weakly bounded forms can still feel materially persuasive. Lecuyer surveys how vision can induce impressions of stiffness, friction, texture, and resistance; Pusch and Lecuyer turn that into practical design guidance; Collins and Kapralos show how cross-modal cueing, including sound, can support the same effect. Even the recent molecular-bond-stiffness work is useful here: people can judge different bond rigidities in VR through simulated response alone. The larger point is that believable materiality can ride coherent physics and sensory alignment without requiring skin-like rendering or dedicated haptic hardware (Lecuyer; Pusch and Lecuyer; Collins and Kapralos; Roebuck Williams et al.).
Bernal and Maes widen the XR picture further by showing that expressive, nonhuman avatar forms can become socially legible through transformed figure languages. Their fur shells and particle systems are driven by physiological and affective change, which matters here because it suggests a wider principle: coherence can be maintained through responsive transformation, not only through surface likeness (Bernal and Maes).
Liedgren, Desmet, and Gaggioli supply the final part of the XR picture. They remind us that transition, framing, invitation, and return are central design materials in their own right. Semi-corporeal form often works through staging as much as depiction. The body does not just appear different; it is introduced, stabilized, and interpreted as a different mode of being there (Liedgren et al.).
Why the pain track belongs here
The pain track is not a tangent. It is where the broader theory becomes experimentally sharp. Jennifer Bullington reframes psychosomatic difficulty not as a narrow body malfunction but as a disturbance in the dialogue between body, person, and world. That matters here because it turns avatar form from a cosmetic issue into a way of reworking lived body-world meaning (Bullington).
The existing avatar-pain literature already supports a modest but important claim: changing embodied visual form can affect pain thresholds, pain ratings, and body perception disturbance. Ho, Lewis, Martini, and Solca all show that therapeutic or analgesic consequences can arise through altered embodiment, multisensory modulation, or changes in the visual organization of the body (Ho et al.; Lewis et al.; Martini et al.; Solca et al.).
Once those findings are placed beside the semi-corporeal archive, a stronger research question opens up. Instead of changing only size, color, or texture, what happens if boundary precision, permeability, protective haloing, or distributed body form become the manipulated variables? ETC and Isness matter here not because they are pain studies, but because they show how abstract bodies can remain relationally and experientially operative. Gilland and Bernal matter because they show how such transformations can stay believable and relatable rather than dissolving into arbitrary visual novelty (Desnoyers-Stewart et al.; Glowacki; Gilland 2009; Bernal and Maes).
That line becomes stronger when it is also made reportable. Tactile visualization adds a useful measurement bridge: sensation can be externalized in terms of location, spread, intensity, rhythm, and texture-like quality instead of being reduced to a single pain number. For boundary-softened avatars, that means boundary change can be compared alongside changes in how sensation is mapped and described (Volpato et al.).
Working design rules
The longform argument produces a fairly compact set of design rules. The first is that stable centers matter. A body can become diffuse without becoming unreadable if some anchors remain steady enough for grouping and re-identification. Recognizable cores, rhythms, or movement signatures can hold identity while the periphery blurs, splits, or swarms (Wagemans et al.; Johansson).
The second is that permeability should be stateful. Semi-corporeality works best as a changing condition rather than a static look. Bodies gather, disperse, overlap, merge, and re-individuate. Treating permeability as a state machine instead of a shader choice aligns this line of work with both the plasmatic historical line and the logic of distributed simulation (Eisenstein; Reeves; Reynolds).
The third is that stylization still needs a physical scaffold. Gilland's point is that even highly stylized change becomes believable when it follows observed forces and preserves a coherent underlying energy. That is exactly the right rule for these bodies. The goal is to make the transformation itself intelligible. The same rule helps explain later pseudo-haptic and physics-based XR work: softness, drag, or resistance become believable when the system behaves like a coherent material world instead of an arbitrary effect layer (Gilland 2009; Gilland 2012; Lecuyer; Pusch and Lecuyer).
The fourth is that relation changes everything. Semi-corporeal bodies become most interesting when they mediate contact, coalescence, or social signaling rather than standing alone as self-contained art objects. That is why ETC, Isness, and even Bernal's expressive-avatar experiments matter more here than generic VFX spectacle (Desnoyers-Stewart et al.; Glowacki et al.; Bernal and Maes).
The fifth is that framing cannot be separated from form. Bodies do not mean the same thing in every setting. Whether a transformation reads as aura, apparition, protective field, swarm, or cartoon elasticity depends on pacing, invitation, symbolic register, and scene logic. That is why the media-theory sources and the transition-design sources sit side by side in this archive (Wilson; Bukatman; Owens; Liedgren et al.).
How the argument holds together
Somaesthetics is what holds these materials together. The point is not to accumulate ghostly images, particle systems, and pain papers under one aesthetic mood. The point is to track how designed forms reorganize lived bodily experience, especially at the boundary where self meets world and others (Shusterman; Hook et al.).
Media history supplies a repertoire of boundary operations, perception research explains how coherence survives without sealed surfaces, XR work shows that abstract bodies can still be owned and socially meaningful, and pain studies make the stakes experimentally sharp. That is the common line linking Gilland's physical logic of transformation, pseudo-haptics, Danceroom's physics-based interaction, ETC's aura-touch grammar, and Isness's collective light bodies (Gilland 2009; Wagemans et al.; Lecuyer; Mitchell et al.; Desnoyers-Stewart et al.; Glowacki; Ho et al.).
Read together, these essays move from broad theory to intervention design while the sources page keeps the citation trail legible.
Plasmatic multitudes are not an argument for vagueness. They are an argument for bodies that remain legible while becoming more permeable, more collective, and more transformable than the default avatar shell usually allows.