# Geometry Nodes For Ovrtx

> Author, inspect, and prepare Blender Geometry Nodes assets for predictable OVRTX rendering and USD handoff. Use for procedural geometry, instances, fields, modifiers, or geometry that must survive add-on evaluation through documented add-on and runtime interfaces.

- Skill: `nvidia-omniverse/geometry-nodes-for-ovrtx` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add nvidia-omniverse/geometry-nodes-for-ovrtx`
- Raw SKILL.md: https://api.skillmd.com/api/skills/nvidia-omniverse/geometry-nodes-for-ovrtx/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: Apache-2.0
- Author: NVIDIA-Omniverse (https://skillmd.com/u/nvidia-omniverse)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/nvidia-omniverse/geometry-nodes-for-ovrtx

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# Geometry Nodes for OVRTX

Geometry Nodes is a procedural authoring layer; OVRTX consumes the evaluated
Blender result through the add-on boundary. Preserve the node graph for
editable `.blend` work, but prove that the evaluated result is renderable and
exportable before claiming compatibility.

## When to Use

Use for procedural geometry, instances, fields, modifiers, or geometry that must survive add-on evaluation through documented add-on and runtime interfaces.

## Instructions

1. Save a copy and record Blender/add-on/runtime versions, frame, seed, object
   identity, modifier stack, and node-group inputs. Use deterministic seeds and
   avoid machine-local asset paths.
2. Build a small representative graph first. Give the modifier and node group
   stable names; expose scale, density, material, and seed controls as typed
   inputs. Keep simulation-time dependencies and frame range explicit.
3. Inspect the evaluated dependency graph at the intended frame. Verify finite
   transforms, expected bounds/vertex counts, material assignment, UV or named
   attributes, normals, instance realization policy, and visibility.
4. Test a low-sample Blender preview and then the same scene through
   `ovrtx-current-scene-workflow`. Never call a viewport screenshot proof of
   native OVRTX geometry without checking the active engine and session status.
5. For USD or SimReady handoff, use the add-on's documented export path. Apply
   modifiers or realize instances only when the target contract requires it;
   retain the procedural source `.blend` and record the bake/evaluation choice.
6. Change topology or node inputs in a controlled copy, restart scene generation
   when required, and compare object/prim identity and bounds before and after.

Author node groups through `blender-python-execution` with stable modifier,
node-group, socket, and object names. After each graph mutation call
`view_layer.update()`, obtain the evaluated object from
`bpy.context.evaluated_depsgraph_get()`, and report evaluated bounds and mesh
counts as JSON. Use upstream `blender-modeling` for deterministic mesh helpers
and modifier/instance realization patterns when it is already installed;
otherwise obtain it through `blender-community-skill-bootstrap`.

Read `references/blender-5-node-api.md` before authoring a graph. It contains a
Blender 5.x idempotent node-group transaction using the current interface API,
plus modifier-input and evaluated-mesh rules. Run
`scripts/audit_geometry_nodes.py` with `GN_AUDIT_REQUEST = {"objects":
["GEO-subject"]}` through MCP, or with `--objects` in background Blender.
Require every named object, NODES modifier, node group, geometry interface, and
evaluated mesh check to pass before testing OVRTX. A modifier existing is not
proof that the graph evaluates useful geometry.

## Compatibility checks

- Avoid relying on unsupported custom attributes, anonymous attributes,
  unbounded recursion, or Blender-only Python callbacks in a final handoff.
- Check that generated materials are reachable from the active output and that
  texture/UV attributes have the names the add-on documents.
- Treat a missing mesh, stale instance, wrong frame, or empty render as a
  conversion/evaluation failure, not a reason to substitute a manually modeled
  mesh without disclosure.
- Keep collision proxies and visual geometry separate for OVPhysX; validate
  official authoring and conversion with `simready-addon-install-and-authoring`.
  This skill proves Blender evaluated geometry only.

## Closeout

Summarize the node group/modifier changed, whether evaluated geometry passed,
and any unsupported node or attribute. Add counts, bounds, seeds, paths, or a
full audit only when they help the requested handoff. Clearly label procedural,
baked, native OVRTX, Blender-preview, and postprocessed outputs.