BabylonJS/Babylon.js · error · Error

FrameGraphBloomMergeTask "${this.name}": sourceTexture and b

Error message

FrameGraphBloomMergeTask "${this.name}": sourceTexture and blurTexture are required

What it means

FrameGraphBloomMergeTask merges the source image with a blurred bloom texture, requiring both sourceTexture and blurTexture inputs. record() throws when either handle is undefined.

Source

Thrown at packages/dev/core/src/FrameGraph/Tasks/PostProcesses/bloomMergeTask.ts:23

/**
 * @internal
 */
export class FrameGraphBloomMergeTask extends FrameGraphPostProcessTask {
    public blurTexture: FrameGraphTextureHandle;

    public override readonly postProcess: ThinBloomMergePostProcess;

    constructor(name: string, frameGraph: FrameGraph, thinPostProcess?: ThinBloomMergePostProcess) {
        super(name, frameGraph, thinPostProcess || new ThinBloomMergePostProcess(name, frameGraph.engine));
    }

    public override getClassName(): string {
        return "FrameGraphBloomMergeTask";
    }

    public override record(skipCreationOfDisabledPasses = false): FrameGraphRenderPass {
        if (this.sourceTexture === undefined || this.blurTexture === undefined) {
            throw new Error(`FrameGraphBloomMergeTask "${this.name}": sourceTexture and blurTexture are required`);
        }

        const pass = super.record(skipCreationOfDisabledPasses, undefined, (context) => {
            context.bindTextureHandle(this._postProcessDrawWrapper.effect!, "bloomBlur", this.blurTexture);
        });

        pass.addDependencies(this.blurTexture);

        return pass;
    }
}

View on GitHub (pinned to 0592b347b8)

Solutions

Assign task.sourceTexture to the original scene/source texture handle.
Assign task.blurTexture to the output of the bloom blur (upsampled) task.
Verify the bloom blur task is recorded before the merge task in the graph.

Example fix

// before
bloomMergeTask.sourceTexture = sceneColorTask.output;
context.build();
// after
bloomMergeTask.sourceTexture = sceneColorTask.output;
bloomMergeTask.blurTexture = bloomUpsampleTask.output;
context.build();

Defensive patterns

Strategy: validation

Validate before calling

if (bloomMergeTask.sourceTexture === undefined || bloomMergeTask.blurTexture === undefined) {
  throw new Error("BloomMergeTask requires sourceTexture and blurTexture");
}

Type guard

function isBloomMergeReady(task: FrameGraphBloomMergeTask): boolean {
  return task.sourceTexture !== undefined && task.blurTexture !== undefined;
}

Try / catch

try {
  bloomMergeTask.record();
} catch (e) {
  if (String(e).includes("sourceTexture and blurTexture are required")) {
    console.error("Ensure the bloom blur task runs before the merge task and its output is bound");
  } else throw e;
}

Prevention

Always pair bloom merge with an upstream bloom blur task and bind its output.
Order tasks: source -> downsample/blur -> upsample -> merge.
Add a build-time input completeness check.

When it happens

Trigger: bloomMergeTask.record() with task.sourceTexture === undefined or task.blurTexture === undefined.

Common situations: Using the merge task standalone without the accompanying bloom (downsample/upsample) task that produces blurTexture; failing to link the blur task's output; reordering tasks so inputs are wired after record().

Related errors

AI-assisted analysis of BabylonJS/Babylon.js@0592b347b8 (2026-08-30). Data as JSON: /api/errors/469db28f5adf6a9c. Report an issue: GitHub.