If you've ever noticed your game chugging when looking at a massive forest or a dense city, it might be time to implement a roblox lod system script custom solution to keep your frame rates high. While Roblox has some built-in features like StreamingEnabled, it doesn't always give you the fine-tuned control you need for specific assets. Sometimes you want a specific tree to swap out for a low-poly version at exactly 200 studs, or maybe you want to hide interior furniture entirely when a player is outside a building. That's where a custom script comes in handy.
Why standard streaming isn't always enough
Roblox does a decent job with its internal Level of Detail (LOD) for meshes, but it's often a bit of a "black box." You can't really tell it exactly when to switch or what specific version of a model to show. For a lot of builders and scripters, this lack of control is frustrating. You might have a high-detail car model that's killing performance, and you'd rather replace it with a simple box shape when the player is halfway across the map.
A roblox lod system script custom approach lets you define these rules yourself. Instead of relying on the engine to guess what's important, you can prioritize certain objects. This is especially vital for big open-world games where players have a long draw distance. If you leave everything at max detail, even players with high-end rigs are going to feel the stutter.
The basic logic of a custom LOD system
At its heart, an LOD system is just a distance check. You're essentially asking the game, "How far is the player from this object?" and then deciding which version of the object to show based on that number.
Usually, you'll have three or four "tiers" of a model: 1. LOD0: The high-detail version (the original). 2. LOD1: A simplified version with fewer triangles. 3. LOD2: A very basic shape or even a 2D billboard image. 4. Hidden: The object is completely removed from view.
The script's job is to swap these out seamlessly. The trick is doing this without causing more lag by running too many calculations at once. If you're checking the distance for 5,000 trees every single frame, your script is going to become the very problem you're trying to fix.
Setting up your models for swapping
Before you even touch the code, you need to organize your Workspace. A common way to do this is to group your models into a folder. Inside each model, you'd have your different detail levels. I usually name them "High," "Medium," and "Low."
It's a good idea to make sure the primary part of each model is centered. When the script calculates the distance, it's going to look at the position of that primary part. If your "High" model is centered at one spot and your "Low" model is offset by ten studs, the player will see the object jump or "pop" when the switch happens. That's a total immersion killer.
Writing the core script
When you're putting together your roblox lod system script custom, you want to use RunService.Heartbeat or a simple while true do loop with a meaningful wait time. Personally, I like using a loop that checks every 0.5 to 1 second. Players usually don't move fast enough to notice if an LOD swap is a half-second late, and it saves a ton of CPU power.
The script should iterate through a list of objects you've tagged for LOD. Using the CollectionService is a pro move here. You can tag all your "LOD_Objects" and then the script just loops through everything with that tag.
Inside the loop, you calculate the magnitude between the player's HumanoidRootPart and the object's PrimaryPart. lua local distance = (playerPos - objectPos).Magnitude From there, it's just a series of if-statements. If the distance is less than 50, show the High model. If it's between 50 and 150, show the Medium. Anything further, show the Low or hide it.
Handling the visibility swap
How you actually "swap" the models matters. You could move the unused versions into ServerStorage or ReplicatedStorage, but that can be heavy on the engine if you're doing it constantly. A lighter way is to just toggle the Transparency and CanCollide properties, or simply parent them to a "Hidden" folder within the Workspace.
Actually, for a roblox lod system script custom setup, setting Model.Parent to nil and then back to Workspace is surprisingly efficient for the client to handle, as long as you aren't doing it for hundreds of parts in a single frame. Another popular method is using the Transparency property combined with CanQuery and CanTouch set to false. This keeps the object in memory but stops the engine from trying to render or calculate physics for it.
Don't check every object every frame
I mentioned this earlier, but it's worth repeating because it's the biggest mistake people make. Optimization is about doing the least amount of work possible. Instead of checking every single tree in a forest, you can divide your map into "zones" or "chunks."
If a player is in Zone A, you only need to run the LOD checks for objects in Zone A and maybe the neighboring Zone B. There's absolutely no reason to calculate the distance of a trash can in the city when the player is currently in the mountains. This kind of spatial partitioning makes your roblox lod system script custom way more scalable.
Adding some polish with transitions
If you want to get fancy, you don't have to make the objects just "pop" into existence. That can look a bit janky. Some devs use a "dither" effect or a quick transparency fade. While a true dither is hard to do in Roblox without custom shaders, you can script a fast TweenService to fade the high-poly model out while the low-poly one fades in.
It takes a bit more work to coordinate, but it makes the game feel much more professional. Just be careful—tweens also cost resources. If you have 200 objects fading at once, you're back to square one with the lag.
Testing and tweaking your distances
There isn't a magic number for LOD distances. It depends entirely on your game's art style. If you have a stylized game with big, chunky models, you can probably swap to low-poly versions much sooner. If you're going for realism, you'll need to keep those high-res textures and meshes visible for longer.
I always recommend setting up a simple configuration folder within your script. This way, you can tweak variables like CLOSE_RANGE, FAR_RANGE, and CHECK_INTERVAL without digging through lines of code. It makes playtesting much faster when you can just change a number and see the results instantly.
The role of MeshPart.LevelOfDetail
It is worth noting that Roblox MeshParts have a property called RenderFidelity. Setting this to Performance does give you an automatic LOD system. However, it's often not aggressive enough for massive maps. Using a roblox lod system script custom alongside RenderFidelity is usually the best bet. You let Roblox handle the slight mesh simplifications, and your script handles the major swaps or complete removal of objects.
This hybrid approach gives you the best of both worlds: the engine's built-in optimization for the small stuff and your custom logic for the big, game-breaking assets.
Final thoughts on optimization
At the end of the day, a custom LOD system is about balance. You're trading a little bit of Lua processing power for a lot of GPU breathing room. If you keep your script clean, use CollectionService, and avoid checking distances too frequently, your players will have a much smoother experience.
It's one of those things that players won't necessarily notice if it's working perfectly, but they'll definitely notice if it's missing. High frame rates make a game feel responsive and polished, and taking the time to build a custom solution for your assets is always worth the effort in the long run. Happy scripting!