How do you correctly block vision when the map has diagonal walls and tight tunnels on square grids?

I am setting up a Shackled City campaign (the second time I have done it for a full run). All the maps are on square grids and many have tight tunnels and/or diagonal walls. Furthermore, I am using dynamic lighting. There are two issues I am currently have when testing my setup: The token with sight sometimes drifts outside of the diagonal wall in a room and gets a view of the next room. Is there a suggestion to stop this? Is there a way to make "solid" walls that restrain a token from going through? The tight tunnels are not "grid friendly". Hence, a tunnel may straddle a gridline and only creep 2' in on either side. The result is that the player's token gets shuttled to one or the other side of the straddle and ends up looking at walls. Can a token be taken "off grid movement" temporarily? That is, can I not have a token "snap to grid" for a short time? I suppose I could just tell the players, "Yep, that's a long, winding tunnel and it's a tight fit. If you want to try and squeeze through, let me know before moving because it doesn't obey the grid well." Thank you ahead of time, Roy P.S. I am very impressed with my initial week here on Roll20.

Not an expert on setting up Dynamic lighting, but I'll give a few thoughts. 1. There is not a way to make solid walls that tokens can't pass over. 2. You can use both Fog Of War, AND dynamic lighting. This way you can blacken the areas "over" the wall, so even if a token is moved there, it will remain black even with their dynamic vision. 3. Pressing the "ALT" key while moving a token, lets it move off-grid. The same "ALT" key also may help you with drawing lines that don't snap to grid, if that would help. 4. Another idea is go into your Page Settings for that map page, and change the grid spacing to .5 or .25 instead of "1 unit per square" default. You may have to change the distance there also to make distances work after this, and it may make tokens drop-in at a weird size at first. The upside of this method is you get a lot more "spots" to drop a token, so you could have 4 little anchors for dropping a token per map-square, instead of just 1 position per map square. Gives a little more accuracy/options in where a token sets-down.

Thank you, Gold. The "ALT" movement will be perfectly fine for the tunnels. The diagonal walls that have rooms on the other side will still be an issue, but I think I will just use a little fog of war for those situations. I was trying to only use dynamic lighting, as I didn't see a use for fog of war once dynamic lighting was an option.

Not sure if it will help you, but I have an importer for walle from a gimp path: <a href="https://app.roll20.net/forum/post/949734/script-walls-svg-path-importer-for-dynamic-lighting#post-954175" rel="nofollow">https://app.roll20.net/forum/post/949734/script-walls-svg-path-importer-for-dynamic-lighting#post-954175</a>

Wow. That looks awesome. I will definitely see if I can do it. Thank you.