Composite Collider 2D Issue on Import

[MabLuxx]

I'm having an issue regarding the import process for colliders. My issue is very similar to issue https://github.com/Seanba/SuperTiled2Unity/issues/115, but only in the sense that I am also attempting to curb a massive number of game objects (900+) in my Unity scene. I do not believe the issue is linked to the collision tiles themselves.

From what I understand, Tiled replaces groupings of multiple Polygon Collider 2D's with a single Edge Collider 2D.

I think this is the class that handles that: https://github.com/Seanba/SuperTiled2Unity/blob/master/SuperTiled2Unity/Assets/SuperTiled2Unity/Scripts/Editor/Extensions/CompositeCollider2DExtensions.cs

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I am able to accomplish this by having very simple shapes, regardless of the amount of tiles used to generate them.

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However, if more complex shapes with more edges are created, it results in this error:

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After placing collision on the entire map, I noticed that some of the tiles were consolidated, but others remained as individual Polygon Collider 2D's. My guess is that the import process for converting multiple colliders into a single edge collider runs into an error and stops working partway through, ultimately not deleting the individual objects used to create a composite.

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I have made multiple attempts to identify a threshold or shape that triggers this error, but I cannot seem to find the root of the cause. Here are the version numbers I am currently working with, as well as the map properties from Tiled and collision settings from Unity:

Tiled Editor Version 1.3.2 SuperTiled2Unity Unity Package Version 1.9.1 Unity Version 2019.2.3f1

[MabLuxx]

I am assuming this error is generated by failing to provide a clear path between vertices when a composite collider is generated out of many smaller colliders. I have resolved this issue by better managing collider tiles. This issue may be closed unless there are further comments or issues revolving around this post.

[ijacquez]

Could you elaborate a bit as to how you're better managing collider tiles?

[MabLuxx]

I'm not certain, but I believe the issue was caused by having vertices which were unable to connect with partners cleanly in order to form a clean polygon (such as harsh points). Again, I'm not certain exactly what was causing this, but I fixed it in my project by isolating an area with more complex collision shapes than the rest of the map, and re-adding collision in way that allowed for obvious polygons to generate from the tiles. I am curious to hear if anyone else has tackled this issue and if so how.

[MabLuxx]

Here's an isolated example of the bug.

In the first image the error occurs and the individual polygon colliders are not destroyed. I believe it has something to do with the shape/size of the polygons within the red box. It is my guess that unity has difficulty merging these particular shaped into a single edge collider.

The second image shows the issue resolved. This was done by removing the tiles that were causing Unity to attempt an unstable merge of colliders.

Unfortunately I don't know if this is enough information to solve the root of the issue, but this is how I have been solving it on my end.

[Seanba]

Hi there. I suspect the problem here is the size of your map and that ST2U is trying to create a collider that has two many vertices in it. Changing your map so that is Infinite may help as that will automatically split up the map into 16x16 chunks for you.