Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add rondorkerin/gamestack --skill procedural-geometrygit clone --depth 1 https://github.com/rondorkerin/gamestackWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/rondorkerin/gamestack/procedural-geometry)<a href="https://agentmods.dev/skills/rondorkerin/gamestack/procedural-geometry"><img src="https://agentmods.dev/badge/skills/rondorkerin/gamestack/procedural-geometry/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/rondorkerin/gamestack/procedural-geometry"><img src="https://agentmods.dev/badge/skills/rondorkerin/gamestack/procedural-geometry.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00369 | $0.01517 |
| Opus 5 | $0.00185 | $0.00758 |
| Sonnet 5 | $0.00074 | $0.00303 |
| Haiku 4.5 | $0.00037 | $0.00152 |
Grade A, and why
procedural-geometry scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 45 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Procedural Geometry
How to generate the geometry of a game — terrain, meshes, structures, and scatter — so it is correct (watertight, manifold, properly wound, performant) and varied (perceptually distinct, not parametric oatmeal). Geometry generation is engineerable math: noise as a substrate, modulation and erosion for believability, constraints and hand-placed anchors for "designed-looking" structure, blue-noise for scatter, and topology validators as the non-negotiable correctness floor.
Tier: technical craft (→
gamestack-core). Engine-agnostic geometry-generation math underneath generated terrain, structures, and meshes.
When to use this
- Generating terrain (heightfield or voxel/SDF), and deciding which representation the design actually needs
- Choosing and wiring a mesh-extraction (marching cubes vs dual contouring), erosion, and LOD/chunking pipeline
- Generating structures with L-systems, shape grammars, or wave function collapse / model synthesis
- Authoring the mesh topology validator (winding/normals, manifold, degenerates, watertight)
- Scattering vegetation/props with blue-noise placement, environmental masking, and instancing
- Diagnosing terrain that looks like "noise", structures that read as generated, or meshes with black faces / broken collision
Scope
This skill owns the math and algorithms that produce geometry — meshes, terrain, structures, scatter. It is deliberately narrow. Adjacent concerns live in sibling skills:
- What content means and whether it's perceptually varied at scale (quests, lore, items, the oatmeal problem for content) →
procedural-generation. This skill is the geometric statement of the same hybrid (hand-anchor + constrained fill); that skill is the narrative one. - Making a generated level legible, navigable, gated, and paced →
level-design. This skill is the geometry engine underneath it — grammars/WFC produce the rooms;level-design's principles make them readable. Geometry serves legibility; it does not replace it. - Gating generated output for perceptual sameness and intentionality →
procgen-review. Its oatmeal test runs on the geometry this skill emits; the topology validator here is the correctness floor below that quality gate. - Rendering, culling, and draw-call budgets for the meshes produced →
3d-graphics-and-rendering. Texturing/shading them →shaders-and-vfx. - Macro/world spatial layout, biomes as places, exploration pull →
open-world-design(this skill is the terrain math underneath that layer).
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 45 lines · 369 tokens per session scan A 32938fa075e9
procedural-geometry is a skill published in the GitHub repository rondorkerin/gamestack (27 stars, last pushed 2mo ago), licensed MIT. It adds 369 tokens to every session and 1,517 once invoked, about $0.0018 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
ux-design
Guided, section-by-section UX spec authoring for a screen, flow, or HUD. Reads game concept, player journey, and relevant GDDs to provide context-aware design guidance. Produces ux-spec.md (per screen/flow) or hud-design.md using the studio templates.
architecture-review
Validates completeness and consistency of the project architecture against all GDDs. Builds a traceability matrix mapping every GDD technical requirement to ADRs, identifies coverage gaps, detects cross-ADR conflicts, verifies engine compatibility consistency across all decisions, and produces a PASS/CONCERNS/FAIL…
localize
Full localization pipeline: scan for hardcoded strings, extract and manage string tables, validate translations, generate translator briefings, run cultural/sensitivity review, manage VO localization, test RTL/platform requirements, enforce string freeze, and report coverage.
vertical-slice
Pre-Production validation — build a production-quality end-to-end build to confirm the full game loop is achievable before committing to Production. Run after GDDs, architecture, and UX specs are complete. Produces a PROCEED/PIVOT/KILL verdict that gates the Pre-Production → Production transition.
quick-design
Lightweight design spec for small changes — tuning adjustments, minor mechanics, balance tweaks. Skips full GDD authoring when a system GDD already exists or the change is too small to warrant one. Produces a Quick Design Spec that embeds directly into story files.
soak-test
Generate a soak test protocol for extended play sessions. Defines what to observe, measure, and log during long play sessions to surface slow leaks, fatigue effects, and edge cases that only appear after sustained play. Primarily used in Polish and Release phases.