BabylonJS/Babylon.js · error · Error

${context}/target/path: Invalid value (${channel.target.path

Error message

${context}/target/path: Invalid value (${channel.target.path})

What it means

Animation channels target a node property via channel.target.path (translation, rotation, scale, weights). When the path is none of these, the interpolation-mapping switch has no case and throws this error. The glTF spec defines only those four valid paths.

Source

Thrown at packages/dev/loaders/src/glTF/2.0/glTFLoader.pure.ts:1888

            switch (channelTargetPath) {
                case AnimationChannelTargetPath.TRANSLATION: {
                    properties = GetMappingForKey("/nodes/{}/translation")?.interpolation!;
                    break;
                }
                case AnimationChannelTargetPath.ROTATION: {
                    properties = GetMappingForKey("/nodes/{}/rotation")?.interpolation!;
                    break;
                }
                case AnimationChannelTargetPath.SCALE: {
                    properties = GetMappingForKey("/nodes/{}/scale")?.interpolation!;
                    break;
                }
                case AnimationChannelTargetPath.WEIGHTS: {
                    properties = GetMappingForKey("/nodes/{}/weights")?.interpolation!;
                    break;
                }
                default: {
                    throw new Error(`${context}/target/path: Invalid value (${channel.target.path})`);
                }
            }
            // stay safe
            if (!properties) {
                throw new Error(`${context}/target/path: Could not find interpolation properties for target path (${channel.target.path})`);
            }

            const targetInfo: IObjectInfo<IInterpolationPropertyInfo[]> = {
                object: targetNode,
                info: properties,
            };

            return this._loadAnimationChannelFromTargetInfoAsync(context, animationContext, animation, channel, targetInfo, onLoad);
        });
    }

    /**
     * @hidden

View on GitHub (pinned to 0592b347b8)

Solutions

  1. Correct channel.target.path to one of: translation, rotation, scale, weights.
  2. Re-export the animation from the source tool with a compliant exporter.
  3. Delete the offending animation channel if it is unnecessary.
  4. Run glTF-Validator on the asset to catch all path issues at once.

Example fix

// before
"channels": [{ "sampler": 0, "target": { "node": 0, "path": "position" } }]
// after
"channels": [{ "sampler": 0, "target": { "node": 0, "path": "translation" } }]
Defensive patterns

Strategy: validation

Validate before calling

const VALID_PATHS = ["translation", "rotation", "scale", "weights"];
for (const ch of gltf.animations?.flatMap(a => a.channels) ?? []) {
  if (!VALID_PATHS.includes(ch.target.path)) {
    throw new Error(`Invalid animation target path: ${ch.target.path}`);
  }
}

Type guard

function isValidTargetPath(p: string): p is "translation" | "rotation" | "scale" | "weights" {
  return ["translation", "rotation", "scale", "weights"].includes(p);
}

Try / catch

try { await loadAsset(); } catch (e) {
  if (/Invalid value \(/.test((e as Error).message) && /target\/path/.test((e as Error).message)) {
    // load without animations or fix the asset
  }
}

Prevention

When it happens

Trigger: Loading a glTF animation whose channels[i].target.path is an unknown string (typo, custom value, or exporter bug); e.g. path "position" instead of "translation".

Common situations: Hand-written animation JSON, assets converted from other formats (FBX/BVH converters) that map properties incorrectly, or corrupted files.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of BabylonJS/Babylon.js@0592b347b8 (2026-08-30). Data as JSON: /api/errors/160ced8685cdef4e. Report an issue: GitHub.