{"record":{"id":"488f7104bb605e75","repo":"stride3d/stride","slug":"operator-cannot-be-null-on-this-instance","errorCode":null,"errorMessage":"Operator cannot be null on this instance","messagePattern":"Operator cannot be null on this instance","errorType":"exception","errorClass":"InvalidOperationException","httpStatus":null,"severity":"error","filePath":"sources/engine/Stride.Rendering/Rendering/Images/ColorTransforms/ToneMap/ToneMap.cs","lineNumber":190,"sourceCode":"        [DefaultValue(0f)]\n        public float Brightness\n        {\n            get => Parameters.Get(ToneMapShaderKeys.Brightness);\n            set => Parameters.Set(ToneMapShaderKeys.Brightness, value);\n        }\n\n        public override void PrepareParameters(ColorTransformContext context, ParameterCollection parentCollection, string keyRoot)\n        {\n            base.PrepareParameters(context, parentCollection, keyRoot);\n\n            Operator.PrepareParameters(context, Parameters, \".ToneMapOperator\");\n        }\n\n        public override void UpdateParameters(ColorTransformContext context)\n        {\n            if (Operator == null)\n            {\n                throw new InvalidOperationException(\"Operator cannot be null on this instance\");\n            }\n\n            // Update the luminance\n            var elapsedTime = timer.Elapsed;\n            timer.Restart();\n\n            var luminanceResult = context.SharedParameters.Get(LuminanceEffect.LuminanceResult);\n\n            // Get the average luminance\n            float adaptedLum = luminanceResult.AverageLuminance;\n            if (TemporalAdaptation)\n            {\n                // Get adapted luminance\n                // From \"Perceptual effects in real-time tone mapping\" by Grzegorz Krawczyk, Karol Myszkowski, Hans-Peter Seidel, p. 3, Equation 5\n                adaptedLum = (float)(previousLuminance + (luminanceResult.AverageLuminance - previousLuminance) * (1.0 - Math.Exp(-elapsedTime.TotalSeconds * AdaptationRate)));\n                previousLuminance = adaptedLum;\n            }\n","sourceCodeStart":172,"sourceCodeEnd":208,"githubUrl":"https://github.com/stride3d/stride/blob/96fad776d210c221682aac1ccdf4c79dc046fc38/sources/engine/Stride.Rendering/Rendering/Images/ColorTransforms/ToneMap/ToneMap.cs#L172-L208","documentation":"ToneMap.UpdateParameters throws InvalidOperationException when the Operator property is null. Tone mapping requires a ToneMapOperator to compute the tone curve; without it the parameter update cannot proceed. Unlike argument checks, this indicates the instance itself was misconfigured before rendering.","triggerScenarios":"Adding a ToneMap transform to a ColorTransformGroup and rendering without ever setting its Operator property, or setting Operator to null after construction.","commonSituations":"Creating ToneMap via a parameterless path or deserialization that skips Operator assignment; copying transform setups where only some fields were carried over; forgetting to choose between ACES/Hable/Reinhard operators.","solutions":["Set a tone-mapping operator before rendering, e.g. toneMap.Operator = new ACESOperator();","Pick the operator matching your desired look (ACES, Hable/Uncharted2, Reinhard) in scene setup.","If Operator was nulled dynamically, restore it or disable the ToneMap transform."],"exampleFix":"// before\nvar toneMap = new ToneMap();\ngroup.PostTransforms.Add(toneMap); // Operator null\n// after\nvar toneMap = new ToneMap { Operator = new ACESOperator() };\ngroup.PostTransforms.Add(toneMap);","handlingStrategy":"validation","validationCode":"if (toneMap.Operator == null)\n    toneMap.Operator = new ACESOperator();\ngroup.PostTransforms.Add(toneMap);","typeGuard":"bool IsRenderable(ToneMap t) => t?.Operator != null;","tryCatchPattern":"try { group.Prepare(); }\ncatch (InvalidOperationException ex) when (ex.Message.Contains(\"Operator cannot be null\"))\n{ toneMap.Operator = new ACESOperator(); }","preventionTips":["Always set Operator at ToneMap construction time","Validate the full transform pipeline before first render","Use object initializers so required fields are set inline"],"tags":["invalid-state","tonemap","color-transform"],"backgroundTag":"internal-invariant-violation","analyzedSha":"96fad776d210c221682aac1ccdf4c79dc046fc38","analyzedAt":"2026-09-14T02:59:31.279Z","contentChangedAt":"2026-09-14T02:59:31.279Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}