shader-teardown

Shader Teardown — HLSL → Shader Graph diagram

Turn hand-written shader code into a Mermaid diagram that shows how the same shader should be built in Shader Graph. Every node in the diagram must exist, with those exact port names, in the Shader Graph version the project uses. Use the docs for that version only.

1. Pin the Shader Graph version (always first)

Find the installed com.unity.shadergraph version. Check these in order and stop at the first hit:

1. Packages/packages-lock.json → "com.unity.shadergraph": { "version": "17.3.0", ... }. This is the authoritative source. Shader Graph usually arrives as a URP/HDRP dependency, so it is often not in manifest.json.
2. Packages/manifest.json → "com.unity.shadergraph" (only if it was added explicitly).
3. If a Unity Editor is running with com.unity.pipeline, package_list (see the unity-pipeline-commands skill).
4. No project, or none of the above: ask the user for the Shader Graph version or Unity version. Do not guess silently.

The docs version is the major.minor part: 17.3.0 → 17.3, 14.0.12 → 14.0.

Docs base URL (verified for 14.0, 17.0 and 17.3):

https://docs.unity3d.com/Packages/com.unity.shadergraph@<major.minor>/manual/

• Node library: Node-Library.html → category pages <Category>-Nodes.html (e.g. Math-Nodes.html, UV-Nodes.html)
• Single node: <Node-Name>-Node.html, words joined by - (e.g. Lerp-Node.html, Custom-Function-Node.html)
• Do not use @latest, because it returns 404. Always use the pinned version.

The category set differs between versions. For example, 14.0 has no UI or Custom Render Texture categories, and its Master Stack blocks are listed per pipeline (Built-In-Blocks.html, Universal, High Definition). Don't assume the node list from one version holds for another.

2. Read the shader

Read the whole file, plus any #included project files that hold the logic. Skip Unity's own core includes. Extract:

From the code	Becomes in Shader Graph
Properties { ... } / CBUFFER_START(UnityPerMaterial) vars	Blackboard properties (type, default, reference name)
Tags { "RenderPipeline" = ... }, includes (Core.hlsl = URP, HDRP ShaderPass = HDRP, UnityCG.cginc = Built-in)	Graph target (Universal / HDRP / Built-In)
Lit vs unlit (UniversalFragmentPBR, LightingStandard, or a plain return col;)	Material type (Lit / Unlit / ...)
Blend, ZWrite, Cull, clip() / alpha test, Queue	Graph Settings (Surface Type, Blend, Render Face, Alpha Clipping)
Vertex function math that changes position/normal	Vertex context blocks (Position, Normal, Tangent)
Fragment function results	Fragment context blocks (Base Color, Normal, Metallic, Smoothness, Emission, Alpha, Alpha Clip Threshold, ...)
#pragma shader_feature / multi_compile	Keywords (Boolean / Enum)
Interpolator values passed v2f → fragment	Usually just the matching Input node in the fragment stage, or a Custom Interpolator when the value is computed in the vertex stage