docs(design): 3D terrain with a fixed isometric camera (real Z, 2D sprites preserved) #272

Merged

panda merged 34 commits from design/3d-terrain into main 2026-08-05 19:46:50 +02:00

Conversation 0 Commits 34 Files changed 138 +6910 -62

panda commented 2026-08-04 20:55:35 +02:00

Collaborator

Copy link

Summary

Design-only. Proposes rendering the terrain as real 3D geometry under a fixed orthographic isometric camera, keeping characters/statics as 2D UO sprites billboarded into that world (the Diablo II Resurrected pattern).

Why, in the owner's words: today we simulate Z; in 3D the Z is real. Every recurring failure of recent cycles — cliffs reading as ramps, iso "diamonds"/right angles, terrain unable to occlude the player, roads that must carve the heightfield, the character "climbing like Messner" — is scaffolding to fake verticality inside a 2-D projection.

The invariant that makes this an evolution, not a new game (owner): "alla fine sono asset applicati a celle; pure sul 3D il concetto è identico." The content model is untouched — one terrain per cell, sparse statics, authored Z. A cell was a screen diamond; now it is a quad in space. Zero conversion of the authored world, tiledata, art or statics.

Kept (an earlier draft over-stated a "big deletion"; the owner pushed back and was right):

• the mesh machinery (chunking, windowing, buffers) — only the projection moves to the GPU;
• the display-Z smoothing, which matters MORE in 3D: real lighting is merciless on a raw heightfield's facets (a Minecraft look), so smoothing stays and now also feeds averaged vertex normals;
• the SDF biome blend + atlas, the UO art and its 5 facings, the server, the map format.

Removed: explicit cliff-wall geometry (already reverted — it produced the diamonds) and the manual anti-occlusion overlay (the depth buffer replaces it).

Owner decisions locked: Z scale raised for imposing mountains (display-only, so walkability is unaffected; exact value picked by eye in the spike via ×4/×8/×12/×16); MapEditor posture B in phases — the 3D terrain is a shared component from the start, the editor's 3D view lands right after the spike; multi-level (stacked surfaces) is Phase 2 with a seam left for it.

Gated by a de-risk spike — a real asterra chunk as a 3D mesh, ortho iso camera, one billboard, depth on. Machine gate: flat Z0 must project pixel-identical to today. Owner gates: does it still look like UO, and which Z scale.

How it was tested

N/A — design document only. check-doc-refs clean.

Checklist

• Design-first, spike-gated; no implementation started
• Multi-platform preserved (MonoGame 3D on Win/macOS; SM3 + committed .xnb pattern)
• Server / map format / content model unchanged; display-only
• Invariants Check included in the spec
• Implementation — NOT started; the spike is the next buildable step

Supersedes the rendering half of #268 (pillar 1 retired, pillar 3 fulfilled natively).

## Summary Design-only. Proposes rendering the **terrain as real 3D geometry** under a **fixed orthographic isometric camera**, keeping characters/statics as **2D UO sprites** billboarded into that world (the Diablo II Resurrected pattern). **Why, in the owner's words:** *today we simulate Z; in 3D the Z is real.* Every recurring failure of recent cycles — cliffs reading as ramps, iso "diamonds"/right angles, terrain unable to occlude the player, roads that must carve the heightfield, the character "climbing like Messner" — is scaffolding to fake verticality inside a 2-D projection. **The invariant that makes this an evolution, not a new game** (owner): *"alla fine sono asset applicati a celle; pure sul 3D il concetto è identico."* The content model is untouched — one terrain per cell, sparse statics, authored Z. A cell was a screen diamond; now it is a quad in space. **Zero conversion** of the authored world, tiledata, art or statics. **Kept (an earlier draft over-stated a "big deletion"; the owner pushed back and was right):** - the mesh machinery (chunking, windowing, buffers) — only the projection moves to the GPU; - **the display-Z smoothing, which matters MORE in 3D**: real lighting is merciless on a raw heightfield's facets (a Minecraft look), so smoothing stays and now also feeds **averaged vertex normals**; - the SDF biome blend + atlas, the UO art and its 5 facings, the server, the map format. **Removed:** explicit cliff-wall geometry (already reverted — it produced the diamonds) and the manual anti-occlusion overlay (the depth buffer replaces it). **Owner decisions locked:** Z scale **raised** for imposing mountains (display-only, so walkability is unaffected; exact value picked by eye in the spike via ×4/×8/×12/×16); MapEditor posture **B in phases** — the 3D terrain is a **shared component from the start**, the editor's 3D view lands right after the spike; multi-level (stacked surfaces) is **Phase 2** with a seam left for it. **Gated by a de-risk spike** — a real asterra chunk as a 3D mesh, ortho iso camera, one billboard, depth on. Machine gate: flat Z0 must project **pixel-identical** to today. Owner gates: does it still look like UO, and which Z scale. ## How it was tested N/A — design document only. `check-doc-refs` clean. ## Checklist - [x] Design-first, spike-gated; no implementation started - [x] Multi-platform preserved (MonoGame 3D on Win/macOS; SM3 + committed `.xnb` pattern) - [x] Server / map format / content model unchanged; display-only - [x] Invariants Check included in the spec - [ ] Implementation — NOT started; the spike is the next buildable step Supersedes the rendering half of #268 (pillar 1 retired, pillar 3 fulfilled natively).

panda added 1 commit 2026-08-04 20:55:35 +02:00

docs(design): 3D terrain with a fixed isometric camera — real Z instead of simulated, 2D sprites preserved dbfbd4d65d

panda added 1 commit 2026-08-04 21:01:50 +02:00

docs(plan): 3D terrain de-risk spike — shared camera + mesh maths, real map, Z-scale gate 171001d2f5

panda added 3 commits 2026-08-04 21:19:06 +02:00

feat(render): IsoCamera — shared 3D isometric camera maths derived from the UO projection 4f34ddfc52

feat(render): TerrainMesh3D — world-space terrain mesh with averaged vertex normals ef726f00a1

spike(render): 3D terrain on the real map — ortho iso camera, real normals, depth + billboard d7f2c90790

panda added 1 commit 2026-08-04 21:20:39 +02:00

docs(design): 3D terrain gate PASSED — real verticality confirmed, owner picks Z scale x16 d1800b0c43

panda added 1 commit 2026-08-04 21:24:32 +02:00

spike(render): 3D terrain textured with the real biome art from the asset pack 04ef006d19

panda added 1 commit 2026-08-04 21:25:44 +02:00

docs(design): enumerate the existing visual refinements as a Phase 1 carry-over checklist 9bcbb5ead5

panda added 1 commit 2026-08-04 21:47:55 +02:00

feat(render): 3D terrain in the client — unified projection at Z scale 16, real-normal lighting, height-aware picking 450f08818d

panda added 1 commit 2026-08-04 21:59:17 +02:00

fix(render): ray-march tile picking + movement test suite over procedural terrain with peaks 51c79fee37

panda added 1 commit 2026-08-04 22:04:08 +02:00

docs(design): real Z exposes a walkability gap — steepness/gradient, not just per-step height b0c5e9be00

panda added 1 commit 2026-08-04 22:12:19 +02:00

feat(movement): sustained-climb budget — a route's steepness is limited, not just one step dcbc8c3758

panda added 2 commits 2026-08-04 22:14:49 +02:00

feat(render): projection-aware tiling so cliff faces show rock instead of a stretched smear 0976fd500c

docs(design): record the entity-occlusion approach and its shared-depth-mapping pitfall bae2f5f869

panda added 1 commit 2026-08-04 22:30:39 +02:00

feat(render): entities test the terrain depth buffer — a cliff now hides what is behind it dd290df964

panda added 1 commit 2026-08-04 22:57:15 +02:00

fix(roads): grade roads to the sustainable gradient, not the single-step limit — they were unwalkable by construction 8be3067764

panda added 1 commit 2026-08-04 23:19:45 +02:00

feat(editor): DEBUG automation channel — script the real editing tools reproducibly; rebuild the test mountain and its spiral road f19032b58c

panda added 2 commits 2026-08-04 23:35:40 +02:00

feat(editor): road shoulders — blend terrain beside the carriageway so a road is not a knife-edge causeway 77d533e4ca

feat(render): mobiles join the shared depth buffer — a character behind a mountain is hidden by it e19df07370

panda added 1 commit 2026-08-04 23:49:15 +02:00

fix(editor): densify the road stroke — a fast drag painted disconnected pits instead of a road a2d99472ec

panda added 1 commit 2026-08-05 12:00:26 +02:00

docs(design): landform editor — parametric terrain tools, rotatable/switchable views, editable traces 74d1575e28

panda added 1 commit 2026-08-05 12:05:34 +02:00

docs(plan): landform editor — picking-first, then views, landforms, traces, naturalisation 650a69e9e5

panda added 2 commits 2026-08-05 12:17:07 +02:00

feat(editor): EditorCamera — free orbit camera maths, orthonormal at every angle 76ad7f83fb

feat(editor): MeshPicker — ray-cast picking correct at any camera rotation d7d33b9a31

panda added 1 commit 2026-08-05 12:44:01 +02:00

feat(editor): switchable top-down / orbiting 3D view, with the height window read in bulk 8c5379763a

panda added 1 commit 2026-08-05 12:53:52 +02:00

perf(editor): pick by testing only the cells the view ray crosses — exact, and bounded by the ray not the viewport ba1c1418e0

panda added 1 commit 2026-08-05 13:05:36 +02:00

perf(editor): keep the terrain mesh on the GPU and stop rebuilding it while orbiting 5756508f9f

panda added 2 commits 2026-08-05 13:20:51 +02:00

feat(editor): parametric landforms with a flank profile and a reported max gradient f18c7a598b

feat(editor): landform tool — place a shaped hill or basin, with its climbability reported 47e739914c

panda added 1 commit 2026-08-05 13:31:19 +02:00

feat(editor): roads become re-bakeable Traces, shared by the GUI and the automation channel 699cb57f97

panda added 2 commits 2026-08-05 13:38:58 +02:00

feat(editor): naturalisation — thermal erosion and deterministic seeded roughening 9a24e1af64

feat(editor): warn on exit with unsaved chunks instead of discarding them 1e09538dc9

panda added 1 commit 2026-08-05 13:49:41 +02:00

fix(editor): landform is one placement per click, with a live preview of footprint and profile 8f36192daa

panda added 1 commit 2026-08-05 13:53:50 +02:00

feat(editor): --tool flag for scripted capture; ASCII-safe UI strings (ImGui has no em-dash glyph) 761dda86ce

panda merged commit cc8f2a0b0b into main 2026-08-05 19:46:50 +02:00

panda deleted branch design/3d-terrain 2026-08-05 19:46:50 +02:00

panda referenced this pull request from a commit 2026-08-05 19:46:50 +02:00

docs(design): 3D terrain with a fixed isometric camera (real Z, 2D sprites preserved) (#272)

panda referenced this pull request 2026-08-06 12:50:19 +02:00

fix(client): copertura del terreno consapevole della quota, ricostruita in background #274

panda referenced this pull request 2026-08-06 12:50:37 +02:00

feat(client): terreno 3D — copertura consapevole della quota e ricostruzione in background #273

panda referenced this pull request from a commit 2026-08-06 12:56:02 +02:00

fix(client): copertura del terreno consapevole della quota, ricostruita in background (#274)

Sign in to join this conversation.

Reviewers

No reviewers

Labels

Clear labels   

alpha:wave-0

Alpha — de-risk, do first

  

alpha:wave-1

Alpha — foundations

  

alpha:wave-2

Alpha — features

  

alpha:wave-3

Alpha — refine & stabilize

  

area:assets

Art, sound, the assets.isoa pack and its tools

  

area:combat

Combat system, weapons, balance

  

area:ecology

Natural nodes, harvesting, spawners

  

area:infra

CI, analyzers, dependencies, performance, ops

  

area:render

Client rendering: terrain mesh, shading, sprites, cutaway

  

area:scripting

Lua content scripting host and API

  

area:ui

Client UI, HUD, input, targeting

  

area:world

World model, map format, editor, topology

  

enhancement

New feature or improvement

  

epic

Milestone-level roadmap epic

  

migration

Platform or framework migration

  

post-alpha

Explicitly out of the alpha scope

  

roadmap

Roadmap tracker

  

tech-debt

Accepted debt to revisit

  

type:bug

Something is wrong and reproducible

  

type:chore

Housekeeping: no behaviour change

  

type:design

Design to agree before any implementation

No labels

alpha:wave-0

alpha:wave-1

alpha:wave-2

alpha:wave-3

area:assets

area:combat

area:ecology

area:infra

area:render

area:scripting

area:ui

area:world

enhancement

epic

migration

post-alpha

roadmap

tech-debt

type:bug

type:chore

type:design

Milestone

Clear milestone

No items

No milestone

Projects

Clear projects

No items

No project

Assignees

Clear assignees

No assignees

1 participant

Notifications

Subscribe

Due date

The due date is invalid or out of range. Please use the format "yyyy-mm-dd".

No due date set.

Dependencies

No dependencies set

Reference

marco/IsoMmo!272

No description provided.