What causes "`Uniforms must have a type: '${uniformLine}'`" in BabylonJS/Babylon.js?

Ensure the uniform line includes an explicit concrete GLSL type (float, vec2, etc.).

BabylonJS/Babylon.js · error · Error

`Uniforms must have a type: '${uniformLine}'`

Error message

`Uniforms must have a type: '${uniformLine}'`

What it means

The uniform regex matched, but the type capture group is empty — the declaration has a name but no recognizable type word. The tool needs the type to map to a ConnectionPointType, so it throws with the offending line.

Source

Thrown at packages/dev/smartFilters/src/utils/buildTools/shaderConverter.ts:145

    const uniformRegExp = new RegExp(/(\/\/\s*\{.*\}\s*(?:\r\n|\r|\n)+)?(uniform .*)/gm);
    const uniformGroups = fragmentShader.matchAll(uniformRegExp);
    for (const matches of uniformGroups) {
        const annotationJSON = matches[1];
        const uniformLine = matches[2];

        if (!uniformLine) {
            throw new Error("Uniform line not found");
        }

        const uniformLineMatches = new RegExp(/^uniform\s+(\w+)\s+(\w+)\s*;?/gm).exec(uniformLine);
        if (!uniformLineMatches || uniformLineMatches.length < 3) {
            throw new Error(`Uniforms must have a type and a name: '${uniformLine}'`);
        }
        const uniformTypeString = uniformLineMatches[1];
        const uniformName = uniformLineMatches[2];

        if (!uniformTypeString) {
            throw new Error(`Uniforms must have a type: '${uniformLine}'`);
        }
        if (!uniformName) {
            throw new Error(`Uniforms must have a name: '${uniformLine}'`);
        }

        // Convert to ConnectionPointType
        let type: ConnectionPointType;
        switch (uniformTypeString) {
            case "float":
                type = ConnectionPointType.Float;
                break;
            case "sampler2D":
                type = ConnectionPointType.Texture;
                break;
            case "vec3":
                type = ConnectionPointType.Color3;
                break;
            case "vec4":

View on GitHub (pinned to 0592b347b8)

Solutions

Ensure the uniform line includes an explicit concrete GLSL type (float, vec2, etc.).
Avoid macros/typedefs in uniform type positions; inline the concrete type.
Inspect the line echoed in the error message and fix the declaration.

Example fix

// before
uniform  textureSize;
// after
uniform vec2 textureSize;

Defensive patterns

Strategy: validation

Validate before calling

src.split('\n').forEach((l, i) => { const m = l.trim().match(/^uniform\s+(\w+)\s+(\w+)\s*;?$/); if (l.trim().startsWith('uniform') && (!m || !m[1])) console.error(`Uniform missing type at line ${i+1}`); });

Try / catch

try { await ConvertShader(path, ...); } catch (e) { const m = e.message.match(/Uniforms must have a type: '(.*)'/); if (m) { addConcreteType(m[1]); } else { throw e; } }

Prevention

Use concrete GLSL types (float, vec2, ...) not macros in uniform declarations.
Never leave a uniform declaration incomplete.
Review shader edits for deleted type tokens.

When it happens

Trigger: A uniform declaration like 'uniform someName;' or whitespace/formatting that prevents the (\w+) type capture from matching.

Common situations: Corrupted or partially deleted uniform lines; macro-based types that the regex cannot capture (e.g. uniform PRECISION float x) resolved differently at parse time.

Related errors

AI-assisted analysis of BabylonJS/Babylon.js@0592b347b8 (2026-08-30). Data as JSON: /api/errors/648850ea01916284. Report an issue: GitHub.