Are Objects Split by the culling system

Hi are large object split by the culling system in UE4 or are they left intact.
For example if i create one large object, Like a street scene with buildings down the sides. will this be sliced up or kept as one piece. i know its probably better to have generic pieces that join together to make worlds but i was just wondering about this one for a while.

Also Is there information on the culling system. i moved from Source engine and HAMMER i am the Author of the “Military Industrial Complex 1 and 2 Campaigns”. and i had to be concerned about Culling all the time. it doesn’t seem to be something people are talking much about in UE4. is it done automatically??

Thks Again.

Hi DKnox,

To answer your first question, Culling does not automatically split up objects or remove parts that are unseen from being rendered if the object is a single actor. For instance, if you have a building with multiple interior walls and some additional assets that are all part of the same static mesh, these parts will all still be rendered even though they are not visible to the camera. You would want to have these be modular assets and break the building into smaller chunks to keep them from rendering when not visible.

At the moment, there isn’t a large bit of information available for visibility culling with UE4 and this is a concern that was recently discussed with our learning resources team. There are plans to get this information written up in an easy to follow page. This is also something I’ve been putting together for my personal site that will likely get repurposed for a documentation page starting point. The page I’ve started on is still a little rough and isn’t publicly linked on my site yet but you can read through it here for more information.

That page should contain the answers you’re seeking. Should you have additional questions feel free to post back here. :slight_smile:


Tim I would like to express my gratitude to you for putting together such an informative article! This should be the go-to read on this topic. If you could at some point finish the Tips section that would be awesome. Very very well done Tim!


This has actually be re-worked completely with some MUCH NEEDED clean-up for the documentation in UE4. It’s in the final review process right now. A lot of what was there was my very rough dump of information that needed to be refined into something better! The majority of the tips/troubleshooting section was broken up into Best Practices and Tips & Ticks sections.

Anyway, I’ve copied the Best Practices and Tips&Tricks section to this text document that should help you until this is pushed out live into documentation.

[link text][1]

  • The tip for visualize occluded primitives has a comparison image slider in there that didn’t copy over. This is a simple comparison of the what a view would look like with r.VisualizeOccludedPrimitives would look like when enabled vs if the occluder (a wall) was not blocking the assets.


Hopefully this helps you out, and if you have any concerns or questions about it feel free to let me know. :slight_smile: