[C#] Optimized Randomized Grid Placement for Massive Data Sets
Solution
Unity 2021.x - Unity 6.3.x
Published 16 days ago
Processing 40,000 unique grid positions in a 200x200 area causes application freezes and stack overflow errors due to recursive logic or inefficient List removal operations during large-scale object instantiation. When your script attempts to find non-recurring positions by searching a shrinking pool of available coordinates, the computational cost increases exponentially.
To prevent application instability when populating a high-density grid, developers must shift from recursive calls to iterative logic. High-frequency operations like 200x200 grid calculations quickly exceed the stack limit.
- Initialize a
ListofVector2Intcontaining every coordinate in your grid. - Apply the Fisher-Yates shuffle to the list to randomize the order of positions.
- Iterate through the shuffled list using a for-loop to instantiate objects or assign data.
This Fisher-Yates approach ensures that every position is unique and used exactly once without the performance overhead of checking for duplicates or removing elements from the middle of a collection.
Additional Tips:
- Use a 1D array to represent 2D data for better cache locality and performance when iterating through your grid.
- Avoid using
List.RemoveAtinside a loop as it results in O(n^2) complexity, significantly slowing down your script. - Pre-allocate the capacity of your collection using the constructor to avoid frequent memory reallocations during initialization.
- Consider using
NativeArrayandJobSystemif you need to generate these positions in parallel for even faster performance.
TL;DR
To prevent stack overflow errors when generating a large number of unique grid positions, replace recursive methods with iterative loops and use the Fisher-Yates shuffle algorithm.
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