{"record":{"id":"96d4cb64ba69f380","repo":"BabylonJS/Babylon.js","slug":"invalid-property-name-in-property-path-tar","errorCode":null,"errorMessage":"Invalid property (${name}) in property path (${targetPropertyPath.join(\".\")})","messagePattern":"Invalid property \\((.+?)\\) in property path \\((.+?)\\)","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/dev/core/src/Animations/runtimeAnimation.ts","lineNumber":250,"sourceCode":"        if (events && events.length > 0) {\r\n            for (const e of events) {\r\n                this._events.push(e._clone());\r\n            }\r\n        }\r\n\r\n        this._enableBlending = target && target.animationPropertiesOverride ? target.animationPropertiesOverride.enableBlending : this._animation.enableBlending;\r\n    }\r\n\r\n    private _preparePath(target: any, targetIndex = 0) {\r\n        const targetPropertyPath = this._animation.targetPropertyPath;\r\n\r\n        if (targetPropertyPath.length > 1) {\r\n            let property = target;\r\n            for (let index = 0; index < targetPropertyPath.length - 1; index++) {\r\n                const name = targetPropertyPath[index];\r\n                property = property[name];\r\n                if (property === undefined) {\r\n                    throw new Error(`Invalid property (${name}) in property path (${targetPropertyPath.join(\".\")})`);\r\n                }\r\n            }\r\n\r\n            this._targetPath = targetPropertyPath[targetPropertyPath.length - 1];\r\n            this._activeTargets[targetIndex] = property;\r\n        } else {\r\n            this._targetPath = targetPropertyPath[0];\r\n            this._activeTargets[targetIndex] = target;\r\n        }\r\n\r\n        if (this._activeTargets[targetIndex][this._targetPath] === undefined) {\r\n            throw new Error(`Invalid property (${this._targetPath}) in property path (${targetPropertyPath.join(\".\")})`);\r\n        }\r\n    }\r\n\r\n    /**\r\n     * Gets the animation from the runtime animation\r\n     */\r","sourceCodeStart":232,"sourceCodeEnd":268,"githubUrl":"https://github.com/BabylonJS/Babylon.js/blob/0592b347b8a4ee0236089ea86a749cacfdb266d8/packages/dev/core/src/Animations/runtimeAnimation.ts#L232-L268","documentation":"RuntimeAnimation._preparePath resolves multi-segment property paths like 'position.x' by walking intermediate properties on the target. If any intermediate property is undefined at its index, the path is invalid for animation and this error is thrown.","triggerScenarios":"Creating a new RuntimeAnimation (via scene.beginAnimation / beginDirectAnimation) whose targetPropertyPath contains an intermediate property that does not exist on the target, e.g. animating 'foo.bar' on an object with no 'foo'.","commonSituations":"Typos in animation target property paths; animating a property on a mesh whose sub-object was renamed (e.g. 'renderingGroupId' vs actual); targets that are null or shaped differently than expected; GLTF-loaded nodes with different hierarchies.","solutions":["Fix the targetPropertyPath to match the actual object structure","Verify each intermediate property exists on the target before beginAnimation","Log the target object and confirm the property chain at runtime","Guard with typeof checks or optional setup before starting the animation"],"exampleFix":"// before\nscene.beginAnimation(mesh, 0, 100, true); // animation targets \"postion.x\" (typo)\n// after\n// fix path in the Animation:\nnew Animation(\"a\", \"position.x\", 30, ANIMATIONTYPE_FLOAT, ANIMATIONLOOPMODE_CYCLE);","handlingStrategy":"validation","validationCode":"function canAnimatePath(target: any, path: string[]): boolean {\n    let obj = target;\n    for (let i = 0; i < path.length - 1; i++) {\n        if (obj == null || obj[path[i]] === undefined) return false;\n        obj = obj[path[i]];\n    }\n    return obj != null && obj[path[path.length - 1]] !== undefined;\n}\n// before beginAnimation:\nif (!canAnimatePath(mesh, animation.targetPropertyPath)) { ... }","typeGuard":null,"tryCatchPattern":"try {\n    scene.beginAnimation(mesh, 0, 100, true);\n} catch (e) {\n    if (e.message.includes(\"Invalid property\")) {\n        console.error(\"Bad animation path:\", e.message, \"on target\", mesh?.name);\n    }\n}","preventionTips":["Verify target property paths against the actual object (log Object.keys)","Watch for typos in targetProperty strings","Re-validate paths after upgrading Babylon or changing loaded asset structure"],"tags":["animation","property-path","validation"],"backgroundTag":"invalid-property-path","analyzedSha":"0592b347b8a4ee0236089ea86a749cacfdb266d8","analyzedAt":"2026-08-30T15:11:20.442Z","schemaVersion":2},"datasetVersion":"2026-08-30T18:17:15.746Z"}