# Terrain brush not where cursor is.
**URL:** https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290
**Category:** Terrain
**Created:** [April 1, 2013, 8:57pm UTC](https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290 "2013-04-01T20:57:30Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Blizzagen2](https://discussions.unity.com/u/Blizzagen2)
#### Post date: [April 1, 2013, 8:57pm UTC](https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290/1 "2013-04-01T20:57:30Z")
Hi,
The terrain paintbrush/raise/lower brush is not synced up, for lack of a better term, with where my cursor is. My cursor can be clicking away in the middle of the screen with nothing happening, and then I zoom out and notice the corner of the terrain is risen/lowered/textured etc. The effect is lessened with larger terrains but there is still a fair distance between the cursor + brush.
I have reinstalled Unity to no effect.
Here are two other threads from March and May 2012 with people experiencing the same problem.
[http://forum.unity3d.com/threads/126274-Terrain-Brush-Not-Lining-up-with-Cursor](http://forum.unity3d.com/threads/126274-Terrain-Brush-Not-Lining-up-with-Cursor)
[http://answers.unity3d.com/questions/240059/when-editing-terrain-brush-does-not-fall-on-cursor.html](http://answers.unity3d.com/questions/240059/when-editing-terrain-brush-does-not-fall-on-cursor.html)
This is really frustrating. I’d really appreciate any advice.
Thanks,
---
### Author:  [@TheEShearer](https://discussions.unity.com/u/TheEShearer)
#### Post date: [May 27, 2015, 3:14am UTC](https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290/2 "2015-05-27T03:14:00Z")
After struggling with this for a day or two, i was finally able to get it to work again by simply unchecking the terrain collider in the inspector and then turning it back on again.
---
### Author:  [@armaan8014](https://discussions.unity.com/u/armaan8014)
#### Post date: [February 18, 2020, 1:35pm UTC](https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290/3 "2020-02-18T13:35:21Z")
> [@TheEShearer](#):
>
> After struggling with this for a day or two, i was finally able to get it to work again by simply unchecking the terrain collider in the inspector and then turning it back on again.
5 years later - thank you!!
---
### Author:  [@konpet](https://discussions.unity.com/u/konpet)
#### Post date: [December 19, 2021, 7:30pm UTC](https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290/4 "2021-12-19T19:30:25Z")
Thank you for this! For me it did not work out just by unchecking, I am not sure how I did it, but it eventually worked, after I did it 10 times and reset the Terrain Collider block, and unchecked again. Really annoying problem to say the least…
---
### Author:  [@donkey0t](https://discussions.unity.com/u/donkey0t)
#### Post date: [April 30, 2023, 7:45am UTC](https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290/5 "2023-04-30T07:45:55Z")
I had a similar problem after changing the resolution settings with the newer Unity Terrain tools. Restarting Unity seemed to solve it
---
### Author:  [@Nonearthanti](https://discussions.unity.com/u/Nonearthanti)
#### Post date: [April 19, 2026, 12:36pm UTC](https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290/6 "2026-04-19T12:36:15Z")
11 years later and turning the collider off and on again still worked. Thank you.
---
### Author:  [@kegfutsaw334](https://discussions.unity.com/u/kegfutsaw334)
#### Post date: [June 16, 2026, 7:14am UTC](https://discussions.unity.com/t/terrain-brush-not-where-cursor-is/501290/7 "2026-06-16T07:14:02Z")
Since this is still an issue after all these years I’ll share my automatic fix that doesn’t require saving or toggling the terrain collider. Create a file called TerrainUndoResync.cs in Assets\Editor\ and paste in the following code (must be placed in each individual project):
```auto
// TerrainUndoResync.cs
//
// Fixes the terrain brush desync after undo WITHOUT saving the scene or toggling the terrain collider.
//
// Why simply invoking SyncHeightmap() does nothing:
// Terrain sculpting happens on the GPU heightmap. Undo reverts that GPU
// heightmap (so the terrain LOOKS correct) but does NOT mark any region
// dirty. SyncHeightmap() only propagates regions that are flagged dirty, so
// with nothing flagged it was a no-op -- the CPU heightmap and the collider
// (which the brush raycasts against) kept the stale, pre-undo heights.
//
// The fix: mark the ENTIRE heightmap dirty, then sync. That forces the reverted
// GPU heights down onto the CPU data + collider, realigning the brush with what
// you see.
//
// Runs automatically on undo/redo.
using UnityEditor;
using UnityEngine;
[InitializeOnLoad]
public static class TerrainUndoResync
{
static TerrainUndoResync()
{
Undo.undoRedoPerformed -= OnUndoRedo;
Undo.undoRedoPerformed += OnUndoRedo;
}
// Defer one tick so the terrain has finished reverting before we resync.
static void OnUndoRedo() => EditorApplication.delayCall += Resync;
[MenuItem("Tools/Resync Terrain (Dirty + Sync) %&r")]
static void Resync()
{
var terrains = Object.FindObjectsByType(FindObjectsSortMode.None);
int n = 0;
foreach (var terrain in terrains)
{
var data = terrain != null ? terrain.terrainData : null;
if (data == null) continue;
int res = data.heightmapResolution;
// Mark the whole heightmap dirty so SyncHeightmap has something to
// propagate (this is the step undo skips), then push it through to
// the CPU heights, the LOD mesh, and the collider.
data.DirtyHeightmapRegion(
new RectInt(0, 0, res, res),
TerrainHeightmapSyncControl.HeightAndLod);
data.SyncHeightmap();
n++;
}
}
}
```
Tested and confirmed working. Fix generated with Claude Opus 4.8