# `react-doctor/r3f-webgpu-no-legacy-material-api`

Legacy shader material API inside an R3F WebGPU Canvas

- **Category:** Bugs
- **Severity:** error
- **Source:** oxlint-plugin-react-doctor
- **Framework:** global
- **Enabled when:** react, r3f

## Validate the diagnostic

Confirm the reported code matches this rule before you edit it.

Confirm the reported code matches `react-doctor/r3f-webgpu-no-legacy-material-api`. Compare it with the Before example and verify the same API, framework, and execution context. Treat it as a false positive only when one of those conditions differs.

## Compare the code

The corrected pattern shows a focused way to address the diagnostic.

### Reported pattern

```tsx
import { Canvas } from "@react-three/fiber/webgpu";
<Canvas>
  <mesh>
    <shaderMaterial fragmentShader={`
      void main() {
        gl_FragColor = vec4(1.0, 0.5, 0.25, 1.0);
      }
    `} />
  </mesh>
</Canvas>
```

### Corrected pattern

```tsx
import { Canvas } from "@react-three/fiber/webgpu";
import { color } from "three/tsl";
<Canvas>
  <mesh>
    <meshBasicNodeMaterial
      colorNode={color(1.0, 0.5, 0.25)}
    />
  </mesh>
</Canvas>
```

## How to fix

Use the corrected pattern as a reference. Preserve behavior that the rule does not require you to change.

### Copyable fix prompt

Copy this self-contained prompt into your coding agent after you confirm the diagnostic.

````text
Fix every confirmed `react-doctor/r3f-webgpu-no-legacy-material-api` diagnostic in the current repository.

Required change:
- Use Three.js node materials and TSL for custom shaders rendered by the WebGPU backend.

Reference transformation:

Before:
```tsx
import { Canvas } from "@react-three/fiber/webgpu";
<Canvas>
  <mesh>
    <shaderMaterial fragmentShader={`
      void main() {
        gl_FragColor = vec4(1.0, 0.5, 0.25, 1.0);
      }
    `} />
  </mesh>
</Canvas>
```

After:
```tsx
import { Canvas } from "@react-three/fiber/webgpu";
import { color } from "three/tsl";
<Canvas>
  <mesh>
    <meshBasicNodeMaterial
      colorNode={color(1.0, 0.5, 0.25)}
    />
  </mesh>
</Canvas>
```

Constraints:
- Confirm the reported code matches the Before pattern.
- Make the smallest change that fixes the root cause.
- Preserve behavior and interfaces unrelated to this diagnostic.
- Reuse existing project components, utilities, and conventions.
- Do not introduce render-phase side effects, render-phase state updates, or Hooks rule violations.
- Adapt identifiers and framework details instead of copying blindly.
- Do not disable the rule or suppress matching code.
- Confirm this rule is enabled for the project: `react, r3f`.

Verification:
- Run focused tests for the changed behavior.
- Run React Doctor and confirm this diagnostic no longer appears.
- Report the files changed and any checks you could not run.
````