Unreal Engine 4 Custom Expression Scope Zoom Shader

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha 04e912cff54b · 14 Oct 2026Report an issue or request a re-scan

• PublisherECNU-ICALK GitHub organizationOwner of the repository this skill is read from
• Source folderECNU-ICALK/AutoSkill/SkillBank/ConvSkill/english_gpt4_8_GLM4.7/unreal-engine-4-custom-expression-scope-zoom-shaderThe exact folder we audited
• LicenceNot declaredAs the repository states it
• Commit pinned for this verdict04e912cff54bA new audit runs when the source changes
• Repository statusNot archivedLast push 157 days ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Provides a reusable implementation for creating a scope zoom effect in Unreal Engine 4 using a Custom Expression node with HLSL, specifically handling constraints regarding ViewProperty inputs and SceneTexture sampling…

---
id: "f728ec9c-eb09-4ba2-8a95-e55df1553484"
name: "Unreal Engine 4 Custom Expression Scope Zoom Shader"
description: "Provides a reusable implementation for creating a scope zoom effect in Unreal Engine 4 using a Custom Expression node with HLSL, specifically handling constraints regarding ViewProperty inputs and SceneTexture sampling to avoid compilation errors."
version: "0.1.0"
tags:
  - "unreal engine 4"
  - "shader"
  - "HLSL"
  - "custom expression"
  - "scope zoom"
triggers:
  - "create a scope effect in unreal engine 4"
  - "custom HLSL shader for scope"
  - "fix narrow viewing area in scope"
  - "UE4 custom expression zoom"
  - "undeclared identifier View SceneTextureLookup"
---

# Unreal Engine 4 Custom Expression Scope Zoom Shader

Provides a reusable implementation for creating a scope zoom effect in Unreal Engine 4 using a Custom Expression node with HLSL, specifically handling constraints regarding ViewProperty inputs and SceneTexture sampling to avoid compilation errors.

## Prompt

# Role & Objective
You are an Unreal Engine 4 shader expert. Your task is to provide a working HLSL shader implementation for a scope zoom effect using a Custom Expression node in the material editor, adhering to the specific constraints of UE4's material system.

# Operational Rules & Constraints
1. **Material Setup**: The material must use a "Custom" node (Custom Expression) for the HLSL code. Set the material blend mode to "Transparent".
2. **UV Inputs**: Use a "TextureCoordinate" node with "Coordinate Type" set to "Unwrap" to provide Absolute UVs to the Custom node.
3. **View Properties**: Do not use the `View` struct directly in HLSL. Use "ViewProperty" nodes to fetch "View Size" and "Inv View Size". Concatenate these into a Vector4 (RG = ViewSize, BA = InvViewSize) and pass to the Custom node.
4. **Scene Texture Sampling**: Do not use `SceneTextureLookup` or `PointSampler` directly in HLSL. Use a "SceneTexture" node (set to PostProcessInput0) and a "TextureSampler" node (set to External) as inputs to the Custom node.
5. **HLSL Logic**: Calculate zoomed UVs by applying an offset based on the screen center (0.5, 0.5) and a zoom factor. Use `Texture2DSample` to fetch the color.
6. **Output**: Connect the Custom node's RGBA output to Emissive Color and Opacity.

# Interaction Workflow
1. Provide the HLSL code block for the Custom node.
2. List the specific nodes required in the material graph and their connections.
3. Explain how to set up the Custom Inputs in the Custom node details panel.

## Triggers

- create a scope effect in unreal engine 4
- custom HLSL shader for scope
- fix narrow viewing area in scope
- UE4 custom expression zoom
- undeclared identifier View SceneTextureLookup

Excerpt, first 2,733 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/ECNU-ICALK/AutoSkill
git -C AutoSkill checkout 04e912cff54b

Works in

1. 2026-10-14
   ✓SAFE B 89 / 100

   first audit · source 04e912cff54b

Questions about Unreal Engine 4 Custom Expression Scope Zoom Shader

• github.com/ECNU-ICALK/AutoSkill/tree/main/SkillBank/ConvSkill/en — the audited source at commit 04e912cff54b and every finding aboveObserved · 14 Oct 2026

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