Beams fail to render

Hello there,
I’m looking to switch over from part-based water affects to beam-based. I’ve been able to get this working just fine with the exception that some of the beams won’t render. This seems to be intermittent and not necessarily a bug with me code. I’ve pretty much ruled out all possibilities of it being my code.

This is showing the missing beam, and there are actually a few more. Sometimes when I join the place they all render just fine, other times there are some missing. But for the most part it seems to be random.

During testing I get a pretty solid 60 FPS so I don’t think it’s frame related or anything. I’ve tested on both Mac and Windows with the same issue as well.

I’ve played around with the properties on the beams in the hopes that it would force them to render to no avail. Does anyone know anything about this? Again, I’m pretty certain this isn’t an issue with my code as it would error if one of the beams was just straight up not instanced. I believe this is probably an engine bug but I wanted to see if there was a solution people had found (that and I can’t post in any other more proper channels :frowning:)

Thanks for any assistance!

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I have run into a similar issue before. I think that there is a limit to the number of beams that can be rendered on-screen at the same time, presumably to automatically reduce performance impact. I don’t think this is documented anywhere though, but this design choice can also be seen with other aspects of visual effects, like the number of segments of a beam that are rendered or the number of particles being emitted. Though, I am not 100% confident if this is the issue that is going on.

Could you play around with the number of beams you are using for the water? See if you get more missing beams when you are using more of them.

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If that’s the case it isn’t a fixed limit since I always render the same number with different outcomes. I could play around with the number of beams, sure. But then I get into the territory where it isn’t worth using them due to their fragility and that would make me sad :frowning:.

I’m using a single segment on each beam so the performance impacts are certainly less than that of a part. I’ve tried setting it to 10 segments but that doesn’t seem to change anything. I would imagine that you’re correct but this seems to be a very detrimental feature to have with something you’re counting on to be rendered. There are so many applications for beams, but perhaps their intended purpose is not meant to convey any sort of long-standing visual effect. It is a shame though.

I wonder if there’s any way we could get more information about this. There’s serious benefits to using beams here since they don’t cast shadows. The alternative is parts with decals but the decals actually cast a shadow even if the part has CastShadow set to false. Since the parts/beams are constantly moving the shadows have to be redrawn which impacts performance a bit on lower end machines. I’d hate to abandon this method.