Bizarre lighting problems

So I'm adding the light barriers to a map but I'm getting all kinds of artefacts all over the map. The only thing I can think of that is causing this is that I'm not using straight lines for the light barriers. Any ideas? Examples Light - arrows indicate bogus light barriers Light map of same area Light Light map of same area

This is a recent "bug" that is only affecting LDL. However there is a workaround. It is caused by the recent upgrade that updated one-way walls in UDL. Basically it seems to be that a closed polygon in LDL will produce those spurious light blockers*. The workaround is to not close polygons. One user has developed a script (though this would only be available in game created by a Pro user, of course), that opens closed polygons. Given that development on LDL was frozen nearly two years ago, it is unlikely that anything other than the above workaround will offer a solution. If there is something specific that prevents you from adopting UDL, I or others on the forum might be able to offer solutions. But realistically, this sort of thing will probably happen more and more with LDL. *At first, it seemed that it was caused by overly acute angles. This might not have been the case, but you might see suggestions that state this elsewhere.

FYI here's a link to the script Keith mentioned. Currently requires a manual install. However, I'm not convinced it will help in your situation. You appear to be using freehand paths which I don't think will ever form "closed" polygons. I wonder if you are just overwhelming the system or hitting some effective limit with the sheer number of vertices in your freehand paths, causing the DL to freak out. It's best to avoid freehand in the DL layer anyway, due to potential lag issues. This puts a huge burden on the ray tracing process as there can be orders of magnitude more points to process.

What David said. :) Also, curves (circles) and freehand paths seem to be less of a problem on UDL, particularly circles, but I would just avoid freehand paths for anything. In terms of user experience, they add very little to the esthetic, particularly when drawn over a black or nearly-black background. The simpler the setup, the better the experience for either system.

oh I thought I was using the new lighting. I just checked and I am. The page does not have the legacy lighting check box enabled. So this is a free hand issue you think?

It could be, there seems to be a max number of vertices, and the general advice is that using the polygon tool and short lines is easier on the system than freehand lines.  Another possibility is that little "knot" of lines in the middle screenshot.  You might delete that bit, clean up that corner, and see if that helps.

Thanks. Just to note, the little knot is probably not making much difference. I have these anomalies all over the map, even in "clean" areas.

Here are a couple of examples of ways that you can achieve the same general effect and only employ about 5-10% of the line segments: The bottom line would be the same for red or yellow. The red is how I light block by just using segments to cut off sight lines around corners. The yellow follows the contours a bit more closely and may be less confusing for the players. In either case, let the map image give your characters the walls, and only worry about sight lines. (To be fair, this is pretty much the philosophy you were using, this is just an example of reduction.)

Thanks, Keith. I'll give that a try.

There are some really bizarre effects here. Seems more than some miscalculation of barriers. Nearest logical error seems to be that some of the tokens are blocking light. Note that it would be the token boundary not the image. Also they are not on the grid. So may be some thing with tokens that have light and over lapping tokens. What happens if you move the player tokens away from the light and each other so nothing overlaps?

What you see in the image (the 4 figures) is just one token. I run an old school game with not much importance attached to tactical positioning. I just use roll20 to reveal what the players see. I've double checked the lighting layer and there is absolutely nothing else there other than the visible light lines. I've yet to try Keith's idea of just using straight lines.

OK that has fixed the issue. Seems that the freehand tool was causing it to meltdown. Thanks for the help.

Good to know, thanks for confirming, Andrew. It will help build a case for not using that tool on the DL layer.