# How EffectComposer is used in child objects

**URL:** <https://discourse.threejs.org/t/how-effectcomposer-is-used-in-child-objects/78331>\
**Category:** Questions\
**Tags:** shaders\
**Created:** [February 19, 2025, 8:42am UTC](https://discourse.threejs.org/t/how-effectcomposer-is-used-in-child-objects/78331 "2025-02-19T08:42:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![lyl](https://avatars.discourse-cdn.com/v4/letter/l/dfb087/32.png) [@lyl](https://discourse.threejs.org/u/lyl)\
**Post date:** [February 19, 2025, 8:42am UTC](https://discourse.threejs.org/t/how-effectcomposer-is-used-in-child-objects/78331/1 "2025-02-19T08:42:19Z")

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I declare two Mesh objects that are parent-child, and when I want to use EffectComposer post-processing to highlight the outline of the child object and not highlight the parent object, I add the child object to selectedObjects, but this doesn’t achieve the desired effect. Sub-objects cannot be highlighted separately. What is the reason and how should it be solved?

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**Author:** ![mjurczyk](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.threejs.org/mjurczyk/32/10995_2.png) [@mjurczyk](https://discourse.threejs.org/u/mjurczyk)\
**Post date:** [February 19, 2025, 11:20am UTC](https://discourse.threejs.org/t/how-effectcomposer-is-used-in-child-objects/78331/2 "2025-02-19T11:20:49Z")

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If you mean EffectComposer from [react-postprocessing](https://react-postprocessing.docs.pmnd.rs/effect-composer) - then it’s only top-level, regardless where you’d actually put it within the hierarchy. You can’t limit scope of postprocessing pass by appending EffectComposer only to a specific group / object.

Hard to help without seeing the code - if you actually put the list of objects to be outlined in `selectedObjects` prop, then it’s a typo since that prop is called `selection` ([docs](https://react-postprocessing.docs.pmnd.rs/effects/outline)) ?