Shadow Caster 2D not working on TileMap?

I have Shadow Caster 2D working on regular objects (doors in my game) but it doesn't seem to work on my TileMap walls.

https://imgur.com/a/n7OvxAm

Is this a known issue or am I doing something wrong?

 

The current ShadowCaster2D component appears to only take the bounds of a collider and/or object. You can modify the Awake() function in ShadowCaster2D.cs to check if the type of collider is a polygon, then use the path of the polygon as the shape for the generated shadow mesh. The file was located at "Library\PackageCache\com.unity.render-pipelines.universal@7.1.7\Runtime\2D" for me.

Code (CSharp):

1. private void Awake() {
2.             if(m_ApplyToSortingLayers == null)
3.                 m_ApplyToSortingLayers = SetDefaultSortingLayers();
4.  
5.             Bounds bounds = new Bounds(transform.position, Vector3.one);
6.          
7.             Renderer renderer = GetComponent<Renderer>();
8.             if (renderer != null)
9.             {
10.                 bounds = renderer.bounds;
11.             }
12.             else
13.             {
14.                 Collider2D collider = GetComponent<Collider2D>();
15.                 if (collider != null)
16.                     if (collider.GetType() == typeof(PolygonCollider2D)) {
17.                         m_ShapePath = Array.ConvertAll<Vector2, Vector3>(((PolygonCollider2D)collider).GetPath(0), vec2To3);
18.                         m_UseRendererSilhouette = false;
19.                     } else {
20.                         bounds = collider.bounds;
21.                     }
22.             }
23.  
24.             Vector3 relOffset = bounds.center - transform.position;
25.  
26.             if (m_ShapePath == null || m_ShapePath.Length == 0)
27.             {
28.                 m_ShapePath = new Vector3[]
29.                 {
30.                     relOffset + new Vector3(-bounds.extents.x, -bounds.extents.y),
31.                     relOffset + new Vector3(bounds.extents.x, -bounds.extents.y),
32.                     relOffset + new Vector3(bounds.extents.x, bounds.extents.y),
33.                     relOffset + new Vector3(-bounds.extents.x, bounds.extents.y)
34.                 };
35.             }
36. }

I then use a different script that requires a CompositeCollider2D to be attached to my tilemap and builds a ShadowCaster2D for each distinct path in the composite collider, which looks like the following:

Code (CSharp):

1.  
2. public void Start() {
3.             tilemapCollider = GetComponent<CompositeCollider2D>();
4.             GameObject shadowCasterContainer = GameObject.Find("shadow_casters");
5.             for (int i = 0; i < tilemapCollider.pathCount; i++) {
6.             Vector2[] pathVertices = new Vector2[tilemapCollider.GetPathPointCount(i)];
7.             tilemapCollider.GetPath(i, pathVertices);
8.             GameObject shadowCaster = new GameObject("shadow_caster_" + i);
9.             PolygonCollider2D shadowPolygon = (PolygonCollider2D)shadowCaster.AddComponent(typeof(PolygonCollider2D));
10.             shadowCaster.transform.parent = shadowCasterContainer.transform;
11.             shadowPolygon.points = pathVertices;
12.             shadowPolygon.enabled = false;
13.             ShadowCaster2D shadowCasterComponent = shadowCaster.AddComponent<ShadowCaster2D>();
14.             shadowCasterComponent.selfShadows = true;
15.             }
16. }

Editing ShadowCaster2D should be a somewhat temporary fix until Unity alter the implementation, as in my case it can be refetched and your changes will be lost (unless you fork the ScriptableRenderPipeline repository and point the package manager to use your changes) - so I'd recommend saving the modified ShadowCaster2D script somewhere as a backup to copy and paste if it does the same for you.

 

Thanks, I've tried your fix but I receive the following error after modifying ShadowCaster2D.cs

Library\PackageCache\com.unity.render-pipelines.universal@7.1.5\Runtime\2D\ShadowCaster2D.cs(102,116): error CS0103: The name 'vec2To3' does not exist in the current context

 

Ah I forgot to add this method in my original snippet as-well, add this method in and it should hopefully work:

Code (CSharp):

1. private Vector3 vec2To3(Vector2 inputVector) {
2.     return new Vector3(inputVector.x, inputVector.y, 0);
3. }

 

That fixed the compiler error but sadly the light is still going through my walls.

At least I know it's a limitation of the component. Sounds like it will be better to wait for them to implement Tilemap shadows.

Thanks for your help anyway.

 

@thomasedw Your solution works great! @ayockel90 just make sure that you have a TilemapCollider2D on the tilemap, with the "Used By Composite" checkbox checked, in addition to having a CompositeCollider2D component on there.

 

I made some changes thanks to your ideas and got it working on dynamic tilemaps (adding and removing tiles):
https://forum.unity.com/threads/the-new-2d-lighting-on-tilemaps-advice-and-suggestions.810927/

 

@thomasedw you're amazing! Your fix works perfectly!

 

@thomasedw Well I just discovered that when you close down and reopen Unity, that the ShadowCaster2D script reverts back to it's original form, so anything I added isn't there anymore. Do you know of a way to prevent this?

 

You need to fork this GitHub repository https://github.com/Unity-Technologies/ScriptableRenderPipeline, make changes in that and then you link to your forked version in the package manager by clicking the "+" icon and choosing "Add package from git URL..."

 

@thomasedw Thank you for your help! I tried adding it in the package manager using this forked URL:
https://github.com/ToastandBananas/ScriptableRenderPipeline

But I get an error saying "Cannot perform upm operation: Unable to add package...Package name is invalid. Am I using the incorrect URL?

 

Perhaps change the name of the package... like CustomScriptableRenderPipeline

 

It's been a while since I first added it - but @dotaxis posted on this here: https://forum.unity.com/threads/the-new-2d-lighting-on-tilemaps-advice-and-suggestions.810927/, they altered their manifest.json file directly (incase using the package manager doesn't work).

 

@thomasedw Ahhhh beautiful, this worked perfectly...thanks again, you're awesome!

 

hey, i wrote an alternative script that needs no tinkering with the pipeline package. it uses a simple prefab with nothing but a 1 by 1 shadowcaster, instantiates it a bunch and sets position and scaling (to reduce the number of casters). i posted it on reddit, theres a screenshot aswell, i dont wanna sum it up again^^ https://www.reddit.com/r/Unity3D/comments/ewpoek/script_for_generating_shadowcaster2ds_for_tilemaps/

 

I replied to this here:
https://forum.unity.com/threads/the...s-advice-and-suggestions.810927/#post-5436126

 

Is there any plan by Unity dev team to implement a built-in solution for this?

 

This should really be officially supported by Unity....

 

I do not know if it's the same problem, but I was having issues with shadows when scaling the game object (https://answers.unity.com/questions/1691485/unity-shadow-caster-2d-asset-causing-issues-when-o.html). The issue seems to be fiXed in the lastest release 2020.1.0f1

 

If you would like to avoid having to mess around with packages and forks, you could use reflection instead. I've done:

Code (CSharp):

1.     private static FieldInfo sShapeField = typeof(ShadowCaster2D).GetField("m_ShapePath", BindingFlags.Instance | BindingFlags.NonPublic);
2.  
3.     private static void SetShapePath(ShadowCaster2D caster, Vector2[] points)
4.     {
5.         Vector3[] shapePath = Array.ConvertAll(points, vec2To3);
6.         sShapeField.SetValue(caster, shapePath);
7.     }
8.  
9.     private static Vector3 vec2To3(Vector2 inputVector)
10.     {
11.         return new Vector3(inputVector.x, inputVector.y, 0);
12.     }

 

It's been more than a whole year I posted here about the shadow support for tilemap. A Whole year! And Still ! no support for the shadow tilemap!

 

If anyone else is like me and is doing some 2D stuff with tilemaps and just wants a convenient way to get shadows going with this experimental system, without modifying the package scripts, I've adapted the approach from this thread & another into a component that'll work with an arbitrary input list of CompositeCollider2Ds and create a set of children ShadowCaster2Ds that you can use with a sister CompositeShadowCaster2D script on the parent to conveniently manage a scene with stuff like tilemap colliders.

Code (CSharp):

1. using System;
2. using System.Collections.Generic;
3. using System.Reflection;
4. using UnityEngine;
5. using UnityEngine.Experimental.Rendering.Universal;
6.  
7. /**
8. * Usage: Make an empty game object and attach this component script to it. Drag & drop CompositeCollider2D components
9. * into the sourceColliders field.
10. *
11. * This script isn't ideal, but it's simple and an okay jumping off point for more advanced changes (like caching).
12. *
13. * The main caveat is that it'll regenerate the child objects that comprise the shadow group every time you enter
14. * edit mode. For larger scenes this might be slow or annoying. It's a rough sketch I'm using for a jam game so I'm
15. * not too concerned about this, future travelers may way to dig into more optimal ways of not having to recreate the
16. * child object shadow casters.
17. */
18. [ExecuteInEditMode]
19. [RequireComponent(typeof(CompositeShadowCaster2D))]
20. [DisallowMultipleComponent]
21. public class ShadowWrangler : MonoBehaviour
22. {
23.     public CompositeCollider2D[] sourceColliders = { };
24.  
25.     private static BindingFlags accessFlagsPrivate =
26.         BindingFlags.NonPublic | BindingFlags.Instance;
27.  
28.     private static FieldInfo shapePathField =
29.         typeof(ShadowCaster2D).GetField("m_ShapePath", accessFlagsPrivate);
30.  
31.     private static FieldInfo meshHashField =
32.         typeof(ShadowCaster2D).GetField("m_ShapePathHash", accessFlagsPrivate);
33.  
34.  
35.     // Start is called before the first frame update
36.     void OnEnable()
37.     {
38.         // only refresh this stuff in edit mode since the ShadowCaster components will serialize/persist their
39.         // shadow mesh on their own.
40.         // TODO: maybe only trigger the refresh when a difference is detected
41.         if (Application.isEditor) RefreshWorldShadows();
42.     }
43.  
44.     private void RefreshWorldShadows()
45.     {
46.         ClearChildShadows();
47.         foreach (var source in sourceColliders)
48.         {
49.             CreateGroupsForCollider(source);
50.         }
51.     }
52.  
53.     private void ClearChildShadows()
54.     {
55.         var doomed = new List<Transform>();
56.         for (int i = 0; i < transform.childCount; i++)
57.         {
58.             var child = transform.GetChild(i);
59.             if (child.GetComponent<ShadowCaster2D>() == null || !child.name.StartsWith("_caster_")) continue;
60.             doomed.Add(transform.GetChild(i));
61.         }
62.  
63.         foreach (var child in doomed)
64.         {
65.             DestroyImmediate(child.gameObject);
66.         }
67.     }
68.  
69.     /**
70.      * This is adapted from strategies in these two discussion threads:
71.      * - https://forum.unity.com/threads/shadow-caster-2d-not-working-on-tilemap.793803/
72.      * - https://forum.unity.com/threads/allow-programmatic-manipulation-for-shadowcaster2d-shape.829626/
73.      * Hopefully a day comes where we're allowed to programmatically mutate the shadow caster shape
74.      * programmatically.
75.      */
76.     private void CreateGroupsForCollider(CompositeCollider2D source)
77.     {
78.         for (int i = 0; i < source.pathCount; i++)
79.         {
80.             // get the path data
81.             Vector2[] pathVertices = new Vector2[source.GetPathPointCount(i)];
82.             source.GetPath(i, pathVertices);
83.             Vector3[] finalVerts = Array.ConvertAll<Vector2, Vector3>(pathVertices, input => input);
84.  
85.             // make a new child
86.             var shadowCaster = new GameObject("_caster_" + i + "_" + source.transform.name);
87.             shadowCaster.transform.parent = transform;
88.  
89.             // create & prime the shadow caster
90.             var shadow = shadowCaster.AddComponent<ShadowCaster2D>();
91.             shadow.selfShadows = true;
92.             shapePathField.SetValue(shadow, finalVerts);
93.             // invalidate the hash so it re-generates the shadow mesh on the next Update()
94.             meshHashField.SetValue(shadow, -1);
95.         }
96.     }
97. }

Example scene hierarchy (inputted from a single tilemap's CompositeCollider2D):

Example of the shadow meshes in the scene (the white outline around the main tilemaps):