# Subtractive Blueprint Object

**URL:** <https://forums.unrealengine.com/t/subtractive-blueprint-object/297427>\
**Category:** Blueprint\
**Tags:** unreal-engine, Blueprint, question\
**Created:** [October 27, 2014, 8:58pm UTC](https://forums.unrealengine.com/t/subtractive-blueprint-object/297427 "2014-10-27T20:58:27Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![night\_tig3r\_13](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@night\_tig3r\_13](https://forums.unrealengine.com/u/night_tig3r_13)\
**Post date:** [October 27, 2014, 8:58pm UTC](https://forums.unrealengine.com/t/subtractive-blueprint-object/297427/1 "2014-10-27T20:58:27Z")

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I was wondering if i could make a blueprint object class spawn in as a subtractive object so it would make a space in a long object and moving at the same time.

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**Author:** ![TJ\_V](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/tj_v/32/1008648_2.png) [@TJ\_V](https://forums.unrealengine.com/u/TJ_V)\
**Post date:** [October 28, 2014, 4:46pm UTC](https://forums.unrealengine.com/t/subtractive-blueprint-object/297427/2 "2014-10-28T16:46:42Z")

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Hi night\_tig3r\_13,

If you are talking about the BSP additive and subtractive geometry, they can’t be referenced by blueprint and can’t be manipulated at run-time.

However here is one possible solution, you could create a material with Location Based Opacity and add that to a blueprint. Here is a tutorial on how to set that up.

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Another way would be to create the effect in a modeling program by animating it.

TJ

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**Author:** ![shauki](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@shauki](https://forums.unrealengine.com/u/shauki)\
**Post date:** [August 24, 2015, 8:43am UTC](https://forums.unrealengine.com/t/subtractive-blueprint-object/297427/3 "2015-08-24T08:43:36Z")

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I need to play ground digging. BSP is not supported in realtime and seems cannot control APEX cloth in blueprints neither. What would be your suggestion to simulate excavator works?

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**Author:** ![anonymous\_user\_0e83961b](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_0e83961b](https://forums.unrealengine.com/u/anonymous_user_0e83961b)\
**Post date:** [April 20, 2019, 7:16am UTC](https://forums.unrealengine.com/t/subtractive-blueprint-object/297427/4 "2019-04-20T07:16:45Z")

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hi,  
have you been able to do what you were working on?  
because I am trying to do the same thing and I have tried various things: decals, moving vertices in render target, and also location based opacity.  
problem with location based opacity is, that although it creates the effect as it moves, the effect does not stay there permanently to fake the removal process. if there could be way to, for example, create many instances of the this sphere opacity in run-time for any generated path and in blueprint, that would be awesome.  
do you have any suggestions?