Infinite Radius Limit for Placeable Light & Placeable Spotlight

i think it would be a really good idea to remove the radius limit of 5000 for both of the invisible placeable light & placeable spotlight items, the current limit is very limiting imo & its very difficult to fill up large spaces without the use of a spacelight.

i feel like another great use for this would be for creating custom ambiance in dark condos like art studio’s void, where there are no lights. having a very large radius could mimic something like the sun, and you’d be able to create your own ambiance with that

in addition to the 5000 radius limit thing, im like 99% sure setting the radius higher than 500 doesn’t actually make the radius any bigger

On 90% of the Lights, it doesn’t. The actual size of the radius is based on the object itself, with the floor light and space light have much larger max radii.

That being said, this is because the larger the radius of the light, the more performance it eats up. So in Unreal 4, multiple smaller lights are more efficient than one large light. I don’t know why it’s that way, but it is.

Good to know things haven’t changed that much from Unreal Engine 1. :roll_eyes:

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This is due to how it has to calculate each pixel and overlapping lights all in one frame. Placeable lights are dynamic lights that have to be rendered in real time. Unreal 4 uses deferred rendering, so you’re able to place down a bunch and get decent performance if they are separate and not overlapping. But if you have several large scale lights overlapping you will have to calculate each overlapping light on each pixel they are overlapping.

If you can avoid overlapping the radii of the lights, then you’ll have less to compute. If you overlap lights, though, then you’ll have a huge cost.

A lot has changed. Unreal 1 used forwarded rendering, which cannot render as many dynamic lights as Unreal 4 can, which uses deferred rendering.


I wonder if there’s a way to issue a command to bake lighting (and perhaps other rendering stages) during run-time, like one would in the editor, that would likely make condos with elaborate lighting schemes run smoother. Of course, one would have to commit to a given placeable light configuration.

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There’s no way to do this in run time and we aren’t allowed to borrow source code from the unreal editor (it’s licensed differently from the rest of the software code). Plus baked lighting is extremely CPU intensive. It takes around 20-40 minutes to bake lighting in unreal maps with high end CPU.


That’s peachy.

I had imagined rebuilding lights would take about that amout of time in a contemporary engine, hence the “commit to” statement.