E5 · Publication Volume 27

3D-View Design

camera, orientation, occlusion, transparency and clipping

Learning objectives

  • Explain the analytical and evidence boundary for camera, orientation, occlusion, transparency and clipping.
  • Translate the geological task into explicit entities, visual channels and state transitions.
  • Test correctness, reading error, uncertainty communication and accessibility with ordinary and adversarial fixtures.
  • Produce an inspectable three-dimensional view with saved camera, clipping and occlusion states from synthetic evidence and defend every transformation.

The lesson is complete only when the learner can identify the visual claim, reproduce the inspected state, cite the governing evidence, explain uncertainty and show that an equivalent core task remains possible through the required fallback. A polished screenshot without state, source and evaluation evidence remains unverified.

This lesson is general and institution-neutral. It uses no real company, individual, property, project or identifiable place. Generic roles such as evidence custodian, visualisation designer, domain reviewer and release reviewer describe responsibilities without implying affiliation.

Analytical decision

Use three dimensions only when depth, topology, intersection or spatial configuration materially supports the task. A dramatic perspective may impair distance comparison and hide evidence. Declare coordinate frame, vertical exaggeration, camera projection, up direction, clipping planes and visible object set. Provide plan or section companions when precise comparison is easier there. The view must expose what is behind, inside or outside the current camera rather than letting occlusion masquerade as absence.

Write the intended conclusion and the evidence required to support or refuse it before choosing layout or interaction. Identify a comparison baseline and the cost of a false positive, false negative and unresolved result. A design requirement is testable only when an observer, input, state, expected output and pass condition are named.

Record non-goals as carefully as goals. A view intended for evidence inspection does not automatically support editing, publication or operational control. Restricting scope prevents an apparently convenient interface from acquiring authority that its evidence and validation do not support.

Scientific content

A three-dimensional view is a projection of a spatial scene through camera, clipping, depth and blending functions. Perspective supports shape and relative depth but introduces size variation; orthographic projection supports measurement but can flatten depth cues. Transparency is order-dependent and can create false mixtures. Clipping reveals interior relationships but changes visible topology. Orientation aids, scale cues, section planes and reversible isolation controls make these transformations inspectable.

Distinguish data semantics from portrayal semantics. A geological object retains identity, geometry, support, status and lineage even when invisible; a mark has position, form, colour, texture, opacity and interaction state only within a view. The mapping between them is versioned and may be many-to-one through aggregation or one-to-many through multiple representations.

Perception is part of the measurement system. Position, length, area, angle, colour and depth are decoded with different accuracy and are affected by context. Use the most accurately read channel compatible with the task, reserve emphasis, and verify that a reader sees the intended ordering and distinctions rather than relying on the designer’s familiarity.

View and interaction model

Represent camera state with projection type, position, target, up vector, field of view or orthographic scale, near and far planes, and viewport. Scene state lists object identifiers, transforms, visibility, opacity, clipping participation, render mode and selection status. Save named viewpoints as versioned analytical states, not screenshots. Picking returns the semantic object and world coordinate obtained from the depth solution, followed by a source card that confirms identity and precision.

Separate source data, semantic model, analytical transformation, portrayal specification, interaction state and rendered output. Each boundary has an input contract, deterministic operation, structured diagnostics and output fingerprint. Rendering never becomes the authoritative store for values or identities, and interface defaults never fill missing scientific metadata.

The state model supports a clean initial state, deep link, save, restore, undo, reset, comparison and static export. Derived state is recalculated from canonical inputs. Concurrency or delayed loading cannot change selection membership, filter meaning or scenario identity; if required content is unavailable, the view exposes a pending or failed state with retained context.

Visual invariants and constraints

| Invariant | Required evidence | Failure behaviour | | --- | --- | --- | | Semantic identity survives every view and state | Stable object identifiers and version | Block linkage or label the object unresolved | | Visual encoding matches the declared quantity and support | Field definition, units, support and style rule | Remove the encoding until the contract is repaired | | Observation, interpretation, alternative and unknown remain distinct | Epistemic status and legend test | Preserve the states and issue a visible conflict | | Filtering, selection, camera and scenario state are inspectable | Serialised state and population counts | Do not publish an unexplained view | | The chapter artefact remains reproducible | Inputs, transforms, parameters, tests and fingerprints for an inspectable three-dimensional view with saved camera, clipping and occlusion states | Quarantine the derivative without replacing its sources |

Test invariants at import, transform, state transition, render, export and replay. A pixel snapshot can detect accidental layout change but cannot prove identity, quantity, membership or accessibility. Combine semantic assertions, numerical comparisons, task results, structural inspection and selected image comparisons. Every failure reports object, state, rule, observed result and expected condition.

Hard failures block only affected conclusions or derivatives and never suppress valid source evidence. Warnings state consequence and review path. Informational findings are not styled like errors. Severity follows scientific and decision consequence, not implementation convenience or the visual prominence of the affected mark.

Quantitative evaluation

For a simple perspective camera, projected coordinate follows x^{\prime}=f x/z after transformation into camera space. Small changes in depth therefore alter apparent size, so screen length is not a world measurement. Evaluate picking error in world units, camera reproducibility, clipped-object counts, visibility of required evidence, frame time by scene complexity and task accuracy against a plan or section baseline. Measure vertical exaggeration effects on angle and apparent separation.

Every reported measure includes population, support, unit, exclusions, aggregation, uncertainty where available, evaluation state and version. Stratify results when averaging can hide a consequential subgroup, device mode, scale, scenario or evidence class. A faster interface is not better when it increases wrong confident answers or hides unresolved evidence.

Define the reference answer and allowable tolerance before testing. Where expert interpretation is non-unique, score evidence retrieval, assumption disclosure, alternative comparison and appropriate unresolved behaviour instead of pretending that one geometry is the only correct answer. Preserve raw observations beside aggregate scores so review can diagnose why a task failed.

Evidence and uncertainty

Separate uncertainty in acquisition, location, classification, transformation, interpretation, model choice and visual reading. A thicker boundary, translucent surface or broad envelope is not self-explanatory. The view and its evidence card identify which quantity is uncertain, the spatial or temporal support, the construction method, calibration scope where one exists and the consequence for the current decision.

Preserve received objects, accepted semantic views, analytical derivatives and delivery artefacts as distinct versions. A rendered mark references the exact derivative and can be traced to inputs and activities. Contradictory evidence remains selectable. Missing or invalid metadata produces an unknown, conflict or blocked status; it does not trigger a guessed colour, coordinate, category or confidence.

Evidence completeness and visual clarity are evaluated separately. Removing a difficult record may make a view cleaner while making the scientific conclusion weaker. Every filter reports eligible, visible, selected, excluded and unresolved counts, with reasons. Aggregation retains links to members and exposes when a minority class or narrow feature disappears at the chosen scale.

Interaction, state and interoperability

Interaction is a typed transformation of analytical state. Selection identifies objects; filtering changes eligibility; focus directs attention; camera and clipping change projection; scenario changes an interpretation bundle; editing creates a new domain version. Controls name the state they change and show the result. Consequential changes enter history with prior and resulting fingerprints and can be undone or replayed.

Views exchange stable semantic identifiers, declared ranges and state events, never screen positions or colours as identity. When an object has no representation in a receiving view, the view reports it as unavailable rather than silently dropping it. Counts and evidence cards allow a reviewer to reconcile the same selection across plan, section, three-dimensional, log and table representations.

A saved analytical state contains dataset versions, transforms, classification and style versions, filters, selection, scenario, camera, clipping, layout and unresolved findings. A static representation serialises that state and supplies ordered figures, legends, summaries and evidence tables. It must preserve the claim and support even though exploratory gestures are no longer available.

Accessibility and responsive fallback

Every consequential state and control has a programmatic name, role, value and status, preferably through native structured elements. Keyboard order follows the analytical sequence; focus is visible and not hidden by overlays. Pointer and touch targets have a non-drag alternative. Colour, spatial position, hover and animation are never the sole carriers of identity, warning or uncertainty.

Complex graphics provide a concise purpose and conclusion, a detailed description of relationships, and access to the underlying structured evidence. State changes announce only information needed to continue the task. Dense scenes offer search, grouping and list navigation rather than thousands of meaningless focus stops. User zoom and text spacing do not remove controls or evidence.

Responsive layouts preserve reading and focus order, shared state, counts, legends and source access. At narrow widths, views may stack or use explicit tabs, but hidden panels remain discoverable and their selected-object counts remain visible. The static fallback records current state and limitations and is verified against the same task-and-evidence assertions as the interactive version.

Governance and review

Assign responsibilities to generic roles: evidence custodian preserves received material; domain reviewer defines geological meaning and consequence; visualisation designer implements portrayal and state; accessibility reviewer tests cross-mode access; independent validator challenges claims; release reviewer accepts, blocks or scopes publication. No role can erase contradictory evidence or approve its own unresolved hard failure without recorded review.

A portrayal change is versioned when it can alter interpretation: field choice, transform, aggregation, class breaks, palette, line grammar, projection, exaggeration, smoothing, camera default, clipping, opacity, filter, label priority or fallback. Regression fixtures compare expected membership, geometry, values, reading tasks and accessibility semantics, not only image pixels.

Exceptions state scope, rationale, evidence, risk, approving role, affected versions and review trigger. They do not turn unknown into known or a failed task into success by relabelling. The website hosting this lesson has no ownership or scientific-authority role; it only delivers the tutorial and is not part of the scientific evidence chain.

Integration checkpoint

an inspectable three-dimensional view with saved camera, clipping and occlusion states
an inspectable three-dimensional view with saved camera, clipping and occlusion states

Read the diagram as a reasoning map for camera, orientation, occlusion, transparency and clipping. Solid relationships are required data or state transitions; checks expose assumptions and failure paths; the evidence card and static path keep the result reviewable outside the interactive scene. No element represents a particular product, company, person or named site.

Integrate an inspectable three-dimensional view with saved camera, clipping and occlusion states into the cumulative SYN-VIS workbench. Re-run earlier task, identity, legend, state and fallback fixtures. Record which assumptions changed, which views consume the new state and whether any previously accepted conclusion must be superseded.

Synthetic worked example

SYN-VIS-05 contains two synthetic surfaces, drill traces and a small interpreted volume. From the default perspective, the front surface hides a trace that contradicts the volume. The reviewed design shows an occlusion count, offers reversible isolation, and links a clipping plane to the corresponding section. A named orthographic viewpoint supports distance checks. Vertical exaggeration is displayed in state and reset for measurement. The saved scene can be reconstructed from identifiers and transforms without relying on an image.

  1. Preserve the received evidence and state the target decision without choosing a visual form.
  2. Resolve identity, quantity, support, status, eligible population and uncertainty source.
  3. Apply the versioned transform, portrayal and state transition while retaining diagnostics.
  4. Test the answer, cited evidence and fallback; then issue accept, block or unresolved with reasons.

Practice and assessment

Build an inspectable three-dimensional view with saved camera, clipping and occlusion states against SYN-VIS-05. Preserve the received package. Create one ordinary fixture, one boundary fixture, one deliberately misleading portrayal, one accessibility stress case and one unresolved-evidence case. Submit the task model, semantic and visual contracts, serialised state, interactive or inspectable artefact, static fallback, measured results and release decision.

Acceptance criteria:

  • The intended geological decision, eligible evidence and consequence of error are explicit.
  • Every visible quantity has identity, support, unit, status, transform and version.
  • Observation, interpretation, alternative, missing and unknown states remain distinguishable.
  • Selection, filters, camera, clipping, scenario and hidden evidence can be inspected and replayed.
  • The same core answer and evidence citation are reachable by required input modes and static fallback.
  • All blocking failures remain visible and machine-readable; no source evidence is overwritten.

Run a structured review in which a second reviewer receives only the submitted package. The reviewer must reproduce the target state, answer the task, cite the same evidence objects, identify the main limitation and explain any unresolved result. Record discrepancies as findings against the earliest responsible layer and supersede, rather than overwrite, corrected artefacts.

Common failure modes

  • Using perspective screen distance as a world measurement.
  • Treating occluded evidence as absent evidence.
  • Applying transparency without exposing depth and blend ambiguity.
  • Changing vertical exaggeration without updating state and scale cues.
  • Saving a screenshot instead of reconstructable camera and scene state.

These failures substitute appearance or convenience for evidence. Diagnose the earliest boundary where the unsupported assumption entered, restore the source statement and intended task, make transformation and state explicit, run dependent fixtures and supersede the affected derivative. A warning written after the image is not a repair when the visual claim remains dominant.

Sources and further reading