Create a World Tips and Tricks: Troubleshooting Lag

One of the most upsetting problems you'll ever come across when playing a world you created is terrible lag. By lag, I don't mean minor freezing. I mean the game freezing every few minutes for 30 seconds or longer, to the point where it's unplayable.

When this happens, some people think that it's either a case of bad luck or something they can't help. But believe it or not, lag is not something that springs out of nowhere. It is usually the result of specific causes, each which are easy to pinpoint and resolve. If you're currently tearing your hair out with frustration, let's take a look at the major causes of lag and how you can troubleshoot it.

Cause of Lag #1: Poor Routing

Bad routing is usually the #1 reason why a world will lag heavily. In case you don't know, routing is what allows the game to figure out how to get sims from Point A to Point B. If you did something somehow to break the routing, this will cause severe lag, because the game will then kick into overdrive resetting stuck sims or calculating how to get them from one place to another.

With that being said, what are some of the mistakes you can make that causes poor routing?

Laying paint under bridges
If you lay routing paint under bridges, this stops sims from crossing them. What happens then? Besides your sims not being able to cross your bridges, this can result in lag if the bridge you messed up is the only way that your sims can access the lot. I learned this the hard way when I accidentally painted under this bridge one day. Because there was no other way to get to the lot, the game grinded to a halt when sims tried visiting it. It didn't matter that I had set this lot to no visitors, either.

So be very, very careful with routing paint. Don't do stuff like this:

Placing routing paint under bridges will cause severe lag if there's no other way for
sims to get to the lot on the other side

I read someone on a forum saying that painting them under bridges was okay because some break and some don't. I don't think that's true. Even if it were true, my advice is to never paint under bridges, ever. It's just good practice, and besides, it's not really necessary. There is absolutely no reason to place paint underneath a bridge, especially if it's over water.

Leaving gaps in your routing paint
When painting your terrain with paint, always make sure that you completely cover the area. Don't leave any spaces like this, because this will cause issues:

Leaving holes like this in your routing paint can cause heavy lag.

Creating "trapped" areas
If you're not careful how you paint your routing or lay down objects, you may accidentally create areas where your sims get trapped in them.When sims get trapped, this will cause major routing issues.

Overly Complicated Lot
Some people, when they become experienced in CAW, get very creative with their sculpting and lots. Many of them build complicated structures like piers and staircases that look like they were built into the landscape. These type of lots can turn out to be amazing. Unfortunately, they come with a downside. If done incorrectly, they can cause severe routing issues which result in heavy lag.

Fancy lot, but lots like these can sometimes cause routing issues.

Locked Out NPCs in Apartment Buildings
If you build an apartment building from scratch, you need to use public and hidden markers so you call the game which rooms belong to NPCs and which won't.

That's all well and good. However, if you don't place your markers, staircases or elevators correctly, this will sometimes result in NPCs unable to reach their rooms, leading to a routing issue. You'll know there's a problem when you see a bunch of NPCs standing outside the building or in the lobby complaining that they can't get to their doors. So make sure, when making a building, you don't accidentally lock NPCs out of their apartments.

Chances are that if you committed any of the above routing mistakes, this is what's causing your lag issue. But what if you haven't? What if your routing is fine but you're still experiencing some lag? Below are several more causes of lag:

Cause of Lag #2: Too Many Terrain Paints Per Chunk or Lot

When terrain painting, don't go completely overboard and start laying down 15 different types of paint everywhere. This will completely bog down your world with lag, because you will have placed too many paints inside of your world's chunks. In case you don't know what a chunk is, every world is divided up into several pieces, sort of like a jigsaw puzzle. Each puzzle piece is called a "chunk." To see chunks in your world, go to View-->Show Chunk Boundaries. You will see your world carved up by blue lines. Each area inside a blue line is a chunk:

Never add more than 8 terrain paints per chunk or you'll have lag. Also, when using terrain paints inside of lots, don't go overboard, either. Limit your terrain paints to four per lot.

Cause of Lag #3: Spawners and Effects

Spawners are those little square markers that generate rocks, plants, special effects and other cool stuff for your sims to collect. Effects add neat visual effects for your world, such as rainbows, water splashes, geese, seagulls and other enhancements. Unfortunately, placing too many spawners and effects will cause lag, especially if they're clustered together.

Cause of Lag #4: Unclustered Trees

To increase performance, there is an option in Create a World that allows you to take trees and cluster them into groups. When you don't do this, this can cause lag, especially if you have a lot of trees in your world.

Cause of Lag #5: Too Many Types of Trees and Plants in World and on Lots

It's okay to mix things up and have different types of trees in your world, but if you go overboard and have 30 different trees everywhere, this will cause a problem. Limit your trees to only a handful of types, and plant them in clusters. For example, have your fir trees planted in one area of your world, cherry trees in another area and so on and so forth.

Ditto lots. Have no more than four species of plants on each lot totaling no more than 30.

How to Troubleshoot Lag Issues

Okay, your world is lagging horribly and you're on the verge of tears or ready to smash your computer. What now? Below are some steps you can take to troubleshoot your world:

Option 1: Scan Your World for Trapped Sims
Look all over your world in Live Mode to see if there aren't sims stuck anywhere. Especially look around the entrance of bridges. If you see a bunch of sims all crammed in one place and complaining that they can't move, you'll have to reopen your world to look at your routing data and see why that's happening. Maybe you accidentally painted under a bridge or placed an object where you shouldn't have.

Option 2: Send Sims to Lot
If you can't see where your sims might be trapped, then go into Live Mode, pick a sim, and direct him or her to go to lots, especially community lots. You don't have to actually let them go all the way. You can just click, "Visit," and watch what happens. If the sim immediately walks out the front door, the routing to that lot is okay.

If the game suddenly freezes when you click on a lot, congratulations! You've found out a potential cause for the lag. Now examine the lot and the area around it, including how you laid down your routing paint.

Option 3: Double Check Your Bridges
Make sure that you didn't place any routing paint underneath any bridges in your world.

Option 4: Scan Your Routing Paint for Errors or Potential Issues
Click on "Show Routing Data" in CAW to scan for holes or anything else that looks like it could be causing a problem. For more information on this, check out this tutorial at Mod the Sims. It goes into more detail about what to look for when examining routing data.

Option 5: Check Your Terrain Paints
Make sure you didn't use too many paints when painting your world. Remember--no more than 8 per chunk. Double check each lot to make sure you added no more than 4 paints.

Option 6: Check Your Trees
Did you cluster your trees in Create a World? Did you add too many types of trees in your world and in each lot? Double check.

Option 7: Reduce Spawners and Effects
Reduce your spawners and effects if you placed a lot of them in your world.

Option 8: Try Using Overwatch Mod
You may try all the above options and still come up with no leads as to what's causing your lagging issues. In that case, you may want to try out the Overwatch mod as a last ditch effort. Sims 3 New York has a great tutorial showing builders how to use this mod to test for areas of your world where your sims might be getting trapped. I have not used this method personally, but from what I hear, it works.

Good Luck!

Lag can be a frustrating issue for builders, but luckily, all is not lost. Although it seems difficult to solve at first, the good news is that once you learn what causes it and how to troubleshoot it, you'll be able to fix it in a jiffy.