Dynamic Lighting Tips & Tricks

New to Dynamic Lighting? Welcome in! In this thread, we’re asking our community veterans and staff to come in to share their best tricks and tips for using Dynamic Lighting.  Experienced GMs, share your favourite settings, API integrations and more. New users, if you’re looking for a particular use case, ask! Here are some handy resources: Dynamic Lighting quick checklist to make sure your game is LIT.  Step by step video walkthrough from Nick O.  Help Center for detailed steps .  Reporting a bug? Head to the Dynamic Lighting Product Board to see if it’s something in the works, and to check out what’s coming soon!  If you have an urgent issue, please drop us a help request . And to be clear, this thread is for Dynamic Lighting specific use-case questions, tips, and tricks. Any bug reports or offtopic comments will be recorded internally and deleted. So please make sure to put those reports over in the DL Bug thread or on the Product Board .

One thing that I have found really helpful is to make a few "characters" that represent light sources. For example, I have a candle, a torch, a lantern, a directional lantern, a bonfire, and a little glowing sphere to represent the focus of a spell that sheds light. I have all of these in a separate folder, so I can drag them out when setting up maps or on the fly when players add a lighting element to the game, like throwing or dropping a torch.

The first caution I like to give to any GM using dynamic lighting is about Ctrl-L: it does not give you a player's view of a token!!! .  Which leads into this great Tip from keithcurtis:  Creating a Dummy Account (and why) . Here's a quick troubleshooting checklist for making sure you have lighting set up: Make sure you are using Chrome or Firefox. Make sure you are set to only use either Updated Dynamic Lighting  or  Legacy Dynamic Lighting, not both. Token must have vision enabled. Token must be 'controlled' by the player who is checking vision. You should use a ' dummy account ' in order to see changes live/instantaneously when you make them as GM. There are other benefits as well (streaming, testing macros and other tricks, resetting the game URL). There needs to be a light source. Tokens always emit light from the center of the token -- in LDL it comes from a small point in the center of the image, and in UDL it comes from a circle that is some small percentage of the image size -- so if you set the map image as a light source, you'll get some funky behavior. Token and light source need to be on the correct layers. Make sure you don't have a Fog of War/Permanent Darkness layer on. Make sure you don't have Advanced Fog of War/Explorable Darkness blocking vision. Page 'Cell Width' settings can have an affect on a token's vision, especially if the 'light multiplier' is set to something other than 100%. Switch the Cell Width to '1' and see what happens. Check random other page settings, such as 'Restrict Movement'  There's a lot of gems in the  Roll20 Tips and Tricks (Innovative Solutions to Common Problems)  for a variety of things, but I've included a list of a few specifically for Dynamic Lighting here:  Party Sight Token  - Marius Put building Interiors on Token Layer with AFoW  - Taran Droppable Torch Token  - Gimblejam Placeable Light Sources & Spell Radii  - Blue64 Invisible Tokens - Hidden Light Source  - El Gato of de Churros and others Make Doors on DL Layer Clear to Players  - godthedj Noises in the Dark  - Devin S. Light Crumbs  - keithcurtis Darkness Spell Orb  - Avi The Beholder Anti Magic Field  - keithcurtis Note: if you're visiting the Tips and Tricks thread, here's a request from ketihcurtis: Please only post a complete "stupid trick" here. If you want help working out what might become a trick, start it it in its own thread and please post here when complete. If you just wish to express thanks to someone who just solved a great mystery for you, that's fine—people need recognition for contributing Cool Stuff. Also, feel free to point out refinements or warnings about existing tricks. Every little bit helps. If your post is strong enough, I'll link it on the same line as the referenced post in the index. Just don't clutter the thread with too many thanks and especially long strings of quoted text and images. Help keep this thread clean, organized, and easy to read.

If you're jumping into Dynamic Lighting at the Pro level, there are some API scripts you might find handy: TokenMod -- Set just about anything on a group of tokens, including UDL and LDL light. UDLWindows -- Create see through walls that block your players' movement but let them see beyond.  Works with UDL only. UDLPasswall -- Create passable walls that block your players' sight but let them slip through.  Great for illusory walls, curtains, etc.  Works with UDL only. UniversalVTTImporter -- Import the .dd2vtt format files generated by Dungeon Draw. Walls -- Import DL lines from exports built in GIMP.

To chime in on The Aaron's post, I LOVE the Windows API. It's so cool. I have an almost-but-not-quite off-topic comment to say that currently using Ctrl L should show the line of sight for that one token, and the Explorer path revealed by any token controlled by the player who controls the selected token. And then any light multiplier in effect will show from the selected token as well (vs the player's controls). What I'd love for any of you that have strong feelings about using Ctrl+L to do is head to the Product Board and give feedback on our Line of Sight tool card as the team investigates solutions to implement based on your needs. Back to on topic, for you Pro users with access to the Colored Lighting on Dev, I'm going to try using that to create a pseudo blacklight look where when players decide to turn on a specific light, I'll have some writing on the GM layer (trying to make it really creepy) pop down onto the map layer for a Kids on Bikes game I'm doing. 

I noticed recently after I used a vtt upload that if you have 2 dynamic lighting lines parallel and close together, maybe overlapping, then one seems to be ignored. So you can have a DL lines, one for outer wall, one for inner, and when your inside, the inner one doesn't block line of sight, and when your outside the outer one doesn't. This removes the need to try and put a single thin line down the middle of the wall so players can see both sides of the wall depending on where they are. Try as I might though, I cant find this documented anywhere, or exactly how its done. I have had some success, but not perfected it.  Any thoughts?

That might be responsible for an issue I'm having with LDL, where players are able to "explore" past *well* overlapped lines (for doors/walls), but not actually see.  I've got a series of screenshots detailing it (but this is a tips and tricks thread so...).

Probably more trouble than it's worth, but the easiest way I can think of to make two parallel lines is by drawing a skinny rectangle.  I leave the problem of how to properly overlap the ends as an exercise for the ambitious student.

Any Macros for a directionnal Flash-light in UDL ? 

Sorry i found one nevermind

thx

How can I add lighting the players can't interact with? Trying to use torches, and other sources to provide some, but would like to avoid having the tokens spammed everywhere. I keep seeing in older comments I can add them to the DL layer? I don't got this option. Moving to GM layer hides the light from the players. Am I overlooking something?

Just don't give the players control over the token.  They don't need control for it to shed light..  And moving to the dynamic lighting layer works, but I only do that for light sources that won't be moving (campfires, fireplaces, etc.).  Anything that might be interacted with, I just leave on the token layer and don't give the players control over until or unless they need it.

Snow T. said: How can I add lighting the players can't interact with? Trying to use torches, and other sources to provide some, but would like to avoid having the tokens spammed everywhere. I keep seeing in older comments I can add them to the DL layer? I don't got this option. Moving to GM layer hides the light from the players. Am I overlooking something? You can copy or cut the token, switch to the Walls layer, where you draw all your DL Lines, and paste it there.  Alternatively, if you have common light source tokens set up as characters, you can drag them out from the Journal directly to the Walls layer.

If the light token has some art (like a torch or campfire), you can also place the light source on the map layer. That will show the art but also provide light.

Snow T. said: How can I add lighting the players can't interact with? Trying to use torches, and other sources to provide some, but would like to avoid having the tokens spammed everywhere. I keep seeing in older comments I can add them to the DL layer? I don't got this option. Moving to GM layer hides the light from the players. Am I overlooking something? There is no option to "send" a token to the lighting layer, as from a right-click menu. You need to copy and paste it from the token layer by selecting and copying the token with lighting then navigating to the  lighting layer to paste it, or starting on the lighting layer and dragging tokens to there then making them light sources. Their light still shows when they are on the lighting layer, but the token is purely so you can grab on to something as they are otherwise invisible. I tend to use background objects as lighting, as then I know the source, and can move it or remove it in a pinch. 

You can send a token to the DL layer by turning on Advanced Keyboard Shortcuts . Activate the shortcuts, select the object and press "l" and "," Move selected object(s) to Dynamic Lighting layer   l ,  

There does not seem to be a way to set Explorer mode as pre-explored for players. So made a token controlled by all, gave it full vision, then briefly shifted all Dynamic Lighting layer lines to the GM layer and then back.

Greetings! I have a question. On a map with daylight on, is it possible to make an area darker? Like a house with closed shutters.

There are several ways to "fake" a dimmer light level in a specific area. 1. Create an aura on an invisible token. This is a quick solution for areas that are roughly square or circular. You can stack auras for greater darkness. 2. Create a black polygon over the area and reduce its brightness. When adding the color via the rgb number type two more hexadecimal digits after the number. This will control the transparency. (The interface shows rgb, but the definition can be rgba, the a being the alpha channel, or transparency) #00000088 is roughly 50% opacity black. Put this on the map layer. Token layer objects will still appear full brightness, but the map will be dimmer there. 3) use the dimmer switch to dim daylight levels and put lights in the bright spots. Which method you choose will depend on what best fits your circumstance.

keithcurtis said: There are several ways to "fake" a dimmer light level in a specific area. 2. Create a black polygon over the area and reduce its brightness. When adding the color via the rgb number type two more hexadecimal digits after the number. This will control the transparency. (The interface shows rgb, but the definition can be rgba, the a being the alpha channel, or transparency) #00000088 is roughly 50% opacity black. Put this on the map layer. Token layer objects will still appear full brightness, but the map will be dimmer there. I totally did not know about this.  That is a great tip Keith.  Thanks so much.  That part should work for maps even without Dynamic Lighting, right?  

Correct. You can also do the same trick with a white square to simulate fog, or other colors to promote a mood. Note that the color field will only display rgb (no a) when you open it again, but the values persist.

Hi all, been using UDL for a long time with BGDIA and for those characters with nightvision (60', nocturnal, no tint) it is working really well. We are setting up for a Halloween run of CoS and thought it might be atmospheric to have the light grey tint.  Players love the effect but for me as DM the effect seems to multiply and wash out the map.  Is there a fix I have missed, possible since we weren't using tints and so as soon as UDL was at a place where it worked for us we just rolled dice :) Cheers in advance for any info/ tips

Tip:  Either don't use Explorer Mode, or make sure that tokens are always moved from a single browser.  When a token is moved from a different browser (e.g., if the GM moves a player's token), then the explored areas reset.

I see that someone rolled out some "improved" lighting and fog of war. The old method of turning it off and using only legacy lightning and advanced fog of war no longer works. Can someone tell me how to reset the maps to use old style, no vision, no bugs, no cheating, advanced fog of war? Anyone? I have a new game starting in four hours. Appreciated!

Did I get kicked out?

Why can't I post an image. 

The crisp white background is gone. There you have the ugly image that appears after turning off dynamic lighting. Can some please help?

And now really messed up.

No matter what you do, when you turn off dynamic lighting the visible areas get dark and dingy. That makes no sense. The players can see the maps that I paid for but if you want high quality you have to accept the bugs in UDL or you get a dark map. This is a punch in the face.

And I have players on old slow computers that can't handle the bandwidth that UDL requires. I have a terabyte connection, averages 450 G and I still have issues myself as the Roll20 paid license GM.

Legacy Dynamic Lighting can be turned on in the Page settings, on the Dynamic Lighting Tab, at the very bottom under Advanced & Legacy Settings:

Okay rant continues: I had to turn on Dynamic lighting in one place and turn Dynamic lighting off in a different place, on the same screen. Using the same terminology for different features, in my 30 years as a professional software engineer, is verbotten. But the bit-flip bug with "Reveal Areas" has been around for 8 to 9 months so that's what you get.  

Solution for the next victim: Turn this off: 

And then  turn this on, but you can see that it immedaietly turned itself back off again. I promise to God almighty my lord and savior that this is the process. You have to check that dynamic lighting box and then javascript will turn it back off again behind your back. Also a bad idea from my 30 years of programming, and 20 years in web development.