Moving a squared edged light shaft across the floor to represent moonlight coming in from above?

The title kind of says it. I have a scenario in mind where the players are in a wide open round chamber, a slot in the roof provides a crisp edged rectangle of moonlight onto the floor... the players have until the rectangle moves from X to Y to complete Z. The rest of the room is in low levels of ambient daylight to roughly represent the reflection of the moonlight. i.e. it's not "Pitch Black" The room is kind of "Clock like" in appearance, so I want the light to represent a "Hand" rather than just a blob.  I'm looking for a way to create and move a square of light sort of 3x1 dimensions. I can "automate" the movement by placing it on the map layer with a rollable token, or simply "move it by hand" but I have no idea how to make shaped light, or if its even possible at all. Has anyone had a similar situation and found a way to overcome it, or has any idea how it could be done? Thanks in advance.

I have subsequently discovered a work around that is fiddly and won't work as a rollable token, but it will create shaped light... at least shaped light with angles. I placed lights on the lighting (wall) layer and adjusted the settings so that four of them each created a 90 degree arc 1 unit x 1 unit, these formed the corners. Then a bunch of lights with a 180 degree arc formed the edges, and a couple of tiny little fillers in the middle to cover the points where they didn't quite meet. Simply using "Group" allows the whole thing to be manipulated and turned in any direction, but any effort to change the size will only result in sadness... This will work at a pinch, but will be faffy and annoying, so if anyone knows of a better way I'd love to hear it.

Hi Tommy, Do you have a screenshot of what you are trying to do? Perhaps a sketch?

If you are happy to move it by hand and already have low level ambient light throughout the chamber you could  create a white square/rectangle with ~70%+ transparency as a .png and put that on the token layer with 'emit light' settings high enough to cover the token but not much else... it would give the appearance of a block of light even if the emanation is still circular ;) Smoke and mirrors...

This isn't the room I was talking about, I was setting up this warehouse when the notion of using 90 and 180 degree lights occurred to me. But its a rough idea of the kind of effect I want to create... That rectangle of light is made of 4 x 90 degree lights on the wall/lighting layer jigsawed together with a bunch of 180 lights to provide the hard edges. Ideally I would prefer one token/lightsource that can be manipulated to move in small increments across the map.

If you associate the light tokens all with a character, say Moonlight, you could move them all together with the TokenMod API script: !token-mod --set left|+5 --ids @{Moonlight|character_id} --current-page

This could also be simulated with an enormous black shape with low transparency, with a hole in the middle. Given the way that tinting and transparency work on Roll20 (no blending modes), this might look more realistic than a translucent white square. Put it on the map layer, set it as a drawing so it doesn't snap to grid, and nudge it as needed. This would not even require dynamic lighting, as the black would provide all the "dimming".

OOOH!  That's super clever Keith!  You could still move that with TokenMod, and it would be loads easier to set up.  You could give it dim light to provide the ambient lighting.

Keith that's a great idea. And one I will definitely use in another idea I've had about another round room with complex lighting issues... I think the only issue with this first one would be when the Elves start wanting to know why everything is so dark for them. The second version will feature a round room that is mostly illuminated in the centre where the players will be, but dark around the edges and a light will be reflected onto the outside wall area via a big "magic crystal" set up. So what I will do is take your suggestion and make a giant, low transparency DONUT  with the big hole in the middle and a small hole somewhere in the body, and ROTATE it to have the light move along the wall in a "No... Mr Bond... I expect you to DIE!" kind of way... Aaron, that left to right movement was actually exactly what I wanted, so I just tested it with a one touch macro to nudge it along and it works perfectly with that set up I used. I must have had a mental block with the lights and completely failed to realise that they are also, obviously... Tokens. I'd never associated a basic Light with a Character on its own before. Never had a reason to... Now it's opened up a door that will remain active for some time... (I used to be a theatrical lighting technician, so I'm always keen for anything new with the potential to do cool tricks with lighting...) Thanks for the help guys, much appreciated.

Cool!.  For your beam of light, you could just use a restricted light and rotate it with: !token-mod --set rotation|+3 --ids @{BeamLight|character_id} I love solving problems with API scripts, so if you run up against other interesting problems, definitely reach out. =D

If you wanted this to be an automatic effect, or if you wanted it to evenly progress to a certain point (time-montage style, where at the end of the progression, the light would stop moving, and the party would imagine they have "arrived" at the current time), you could automate that with ZeroFrame's {&delay} tag. An similar example is discussed here .