adammyhre · July 28, 2025 20:56 · Mar 3, 2025 · Mar 1, 2025
diff --git a/WorldSpaceUIDocument.cs b/WorldSpaceUIDocument.cs
@@ -4,7 +4,7 @@
 using UnityUtils;
 
 // https://discussions.unity.com/t/uitoolkit-world-space-support-status/887441/22
-// https://gist.github.com/katas94/7b220a591215efc36110860a0b1125eb/raw/f67f251bbbda65a14fb0bb736b82fe485ee22eb8/WorldSpaceUIDocument.cs
+// https://gist.github.com/katas94/7b220a591215efc36110860a0b1125eb
 public class WorldSpaceUIDocument : MonoBehaviour {
     #region Fields
 
@@ -145,4 +145,15 @@ static Mesh GetQuadMesh() {
 
         return quadMesh;
     }
+
+    void DestroyGeneratedAssets () {
+        if (uiDocument) Destroy(uiDocument);
+        if (renderTexture) Destroy(renderTexture);
+        if (panelSettings) Destroy(panelSettings);
+        if (material) Destroy(material);
+    }
+
+    void OnDestroy () {
+        DestroyGeneratedAssets();
+    }   
 }
diff --git a/DamageNumberSpawner.cs b/DamageNumberSpawner.cs
@@ -0,0 +1,44 @@
+using PrimeTween;
+using UnityEngine;
+using UnityEngine.Pool;
+using UnityUtils;
+
+public class DamageNumberSpawner : MonoBehaviour {
+    [SerializeField] WorldSpaceUIDocument uiDocumentPrefab;
+    [SerializeField] float positionRandomness = 0.2f;
+
+    IObjectPool<WorldSpaceUIDocument> uiDocumentPool;
+    const string k_labelName = "DamageLabel";
+
+    void Awake() => uiDocumentPool = new ObjectPool<WorldSpaceUIDocument>(
+        Create,
+        OnTake,
+        OnReturn,
+        OnDestroy
+    );
+
+    WorldSpaceUIDocument Create() => Instantiate(uiDocumentPrefab, transform, true);
+    void OnTake(WorldSpaceUIDocument uiDocument) => uiDocument.gameObject.SetActive(true);
+    void OnReturn(WorldSpaceUIDocument uiDocument) => uiDocument.gameObject.SetActive(false);
+    void OnDestroy(WorldSpaceUIDocument uiDocument) {
+        if (uiDocument == null) return;
+        Destroy(uiDocument.gameObject);
+    }
+
+    public void SpawnDamageNumber(int amount, Vector3 worldPosition) {
+        Vector3 spawnPosition = worldPosition.RandomOffset(positionRandomness);
+
+        WorldSpaceUIDocument instance = uiDocumentPool.Get();
+        instance.transform.SetPositionAndRotation(spawnPosition, Quaternion.identity);
+        instance.SetLabelText(k_labelName, amount.ToString());
+
+        Vector3 upPosition = instance.transform.position.Add(y: 1f);
+
+        PrimeTweenConfig.warnEndValueEqualsCurrent = false;
+        Sequence.Create(cycles: 1, CycleMode.Yoyo)
+            .Group(Tween.PositionY(instance.transform, endValue: upPosition.y, duration: 0.3f))
+            .Group(Tween.Scale(instance.transform, endValue: 1.5f, duration: 0.3f))
+            .Chain(Tween.PositionY(instance.transform, endValue: -upPosition.y, duration: 0.5f))
+            .ChainCallback(() => uiDocumentPool.Release(instance));
+    }
+}
diff --git a/Enemy.cs b/Enemy.cs
@@ -0,0 +1,22 @@
+using ImprovedTimers;
+using UnityEngine;
+
+public class Enemy : MonoBehaviour {
+    [SerializeField] DamageNumberSpawner damageNumberSpawner;
+    [SerializeField] int damageAmount = 10;
+    [SerializeField] float spawnInterval = 0.2f;
+
+    CountdownTimer timer;
+
+    void Start() {
+        timer = new CountdownTimer(spawnInterval);
+        timer.OnTimerStop += () => {
+            damageAmount = Random.Range(5, 25);
+            damageNumberSpawner.SpawnDamageNumber(damageAmount, transform.position);
+            timer.Start();
+        };
+        timer.Start();
+    }
+
+    public void TakeDamage(int damage) => damageNumberSpawner.SpawnDamageNumber(damage, transform.position);
+}
diff --git a/WorldSpaceUIDocument.cs b/WorldSpaceUIDocument.cs
@@ -0,0 +1,148 @@
+using UnityEngine;
+using UnityEngine.Rendering;
+using UnityEngine.UIElements;
+using UnityUtils;
+
+// https://discussions.unity.com/t/uitoolkit-world-space-support-status/887441/22
+// https://gist.github.com/katas94/7b220a591215efc36110860a0b1125eb/raw/f67f251bbbda65a14fb0bb736b82fe485ee22eb8/WorldSpaceUIDocument.cs
+public class WorldSpaceUIDocument : MonoBehaviour {
+    #region Fields
+
+    const string k_transparentShader = "Unlit/Transparent";
+    const string k_textureShader = "Unlit/Texture";
+    const string k_mainTex = "_MainTex";
+    static readonly int MainTex = Shader.PropertyToID(k_mainTex);
+
+    [Header("Panel Configuration")]
+    [Tooltip("Width of the panel in pixels.")] 
+    [SerializeField] int panelWidth = 1280;
+
+    [Tooltip("Height of the panel in pixels.")] 
+    [SerializeField] int panelHeight = 720;
+
+    [Tooltip("Scale of the panel (like zoom in a browser).")] 
+    [SerializeField] float panelScale = 1.0f;
+
+    [Tooltip("Pixels per world unit. Determines the real-world size of the panel.")] 
+    [SerializeField] float pixelsPerUnit = 500.0f;
+
+    [Header("Dependencies")]
+    [Tooltip("Visual tree asset for this panel.")] 
+    [SerializeField] VisualTreeAsset visualTreeAsset;
+
+    [Tooltip("PanelSettings prefab instance.")] 
+    [SerializeField] PanelSettings panelSettingsAsset;
+
+    [Tooltip("RenderTexture prefab instance.")] 
+    [SerializeField] RenderTexture renderTextureAsset;
+
+    MeshRenderer meshRenderer;
+    UIDocument uiDocument;
+    PanelSettings panelSettings;
+    RenderTexture renderTexture;
+    Material material;
+
+    #endregion
+
+    void Awake() {
+        InitializeComponents();
+        BuildPanel();
+    }
+
+    public void SetLabelText(string label, string text) {
+        if (uiDocument.rootVisualElement == null) {
+            uiDocument.visualTreeAsset = visualTreeAsset;
+        }
+
+        // Consider caching the label element for better performance
+        uiDocument.rootVisualElement.Q<Label>(label).text = text;
+    }
+
+    void InitializeComponents() {
+        InitializeMeshRenderer();
+
+        // Optionally add a box collider to the object
+        // BoxCollider boxCollider = gameObject.GetOrAdd<BoxCollider>();
+        // boxCollider.size = new Vector3(1, 1, 0);
+
+        MeshFilter meshFilter = gameObject.GetOrAdd<MeshFilter>();
+        meshFilter.sharedMesh = GetQuadMesh();
+    }
+
+    void InitializeMeshRenderer() {
+        meshRenderer = gameObject.GetOrAdd<MeshRenderer>();
+        meshRenderer.sharedMaterial = null;
+        meshRenderer.shadowCastingMode = ShadowCastingMode.Off;
+        meshRenderer.receiveShadows = false;
+        meshRenderer.motionVectorGenerationMode = MotionVectorGenerationMode.ForceNoMotion;
+        meshRenderer.lightProbeUsage = LightProbeUsage.Off;
+        meshRenderer.reflectionProbeUsage = ReflectionProbeUsage.Off;
+    }
+
+    void BuildPanel() {
+        CreateRenderTexture();
+        CreatePanelSettings();
+        CreateUIDocument();
+        CreateMaterial();
+
+        SetMaterialToRenderer();
+        SetPanelSize();
+    }
+
+    void CreateRenderTexture() {
+        RenderTextureDescriptor descriptor = renderTextureAsset.descriptor;
+        descriptor.width = panelWidth;
+        descriptor.height = panelHeight;
+        renderTexture = new RenderTexture(descriptor) {
+            name = $"{name} - RenderTexture"
+        };
+    }
+
+    void CreatePanelSettings() {
+        panelSettings = Instantiate(panelSettingsAsset);
+        panelSettings.targetTexture = renderTexture;
+        panelSettings.clearColor = true;
+        panelSettings.scaleMode = PanelScaleMode.ConstantPixelSize;
+        panelSettings.scale = panelScale;
+        panelSettings.name = $"{name} - PanelSettings";
+    }
+
+    void CreateUIDocument() {
+        uiDocument = gameObject.GetOrAdd<UIDocument>();
+        uiDocument.panelSettings = panelSettings;
+        uiDocument.visualTreeAsset = visualTreeAsset;
+    }
+
+    void CreateMaterial() {
+        string shaderName = panelSettings.colorClearValue.a < 1.0f ? k_transparentShader : k_textureShader;
+        material = new Material(Shader.Find(shaderName));
+        material.SetTexture(MainTex, renderTexture);
+    }
+
+    void SetMaterialToRenderer() {
+        if (meshRenderer != null) {
+            meshRenderer.sharedMaterial = material;
+        }
+    }
+
+    void SetPanelSize() {
+        if (renderTexture != null && (renderTexture.width != panelWidth || renderTexture.height != panelHeight)) {
+            renderTexture.Release();
+            renderTexture.width = panelWidth;
+            renderTexture.height = panelHeight;
+            renderTexture.Create();
+
+            uiDocument?.rootVisualElement?.MarkDirtyRepaint();
+        }
+
+        transform.localScale = new Vector3(panelWidth / pixelsPerUnit, panelHeight / pixelsPerUnit, 1.0f);
+    }
+
+    static Mesh GetQuadMesh() {
+        GameObject tempQuad = GameObject.CreatePrimitive(PrimitiveType.Quad);
+        Mesh quadMesh = tempQuad.GetComponent<MeshFilter>().sharedMesh;
+        Destroy(tempQuad);
+
+        return quadMesh;
+    }
+}