Added checks to avoid problems when an invalid render size is used

Assets/Scripts/Fsr2ImageEffect.cs

@@ -121,14 +121,24 @@ namespace FidelityFX
             
             // Apply a mipmap bias so that textures retain their sharpness
             float biasOffset = Fsr2.GetMipmapBiasOffset(_renderSize.x, _displaySize.x);
-            Callbacks.ApplyMipmapBias(biasOffset);
-            
+            if (!float.IsNaN(biasOffset))
+            {
+                Callbacks.ApplyMipmapBias(biasOffset);
+            }
+
             if (!SystemInfo.supportsComputeShaders)
             {
                 Debug.LogError("FSR2 requires compute shader support!");
                 enabled = false;
                 return;
             }
+
+            if (_renderSize.x == 0 || _renderSize.y == 0)
+            {
+                Debug.LogError($"FSR2 render size is invalid: {_renderSize.x}x{_renderSize.y}. Please check your screen resolution and camera viewport parameters.");
+                enabled = false;
+                return;
+            }
             
             _helper = GetComponent<Fsr2ImageEffectHelper>();
             
@@ -163,8 +173,11 @@ namespace FidelityFX
         {
             // Undo the current mipmap bias offset
             float biasOffset = Fsr2.GetMipmapBiasOffset(_renderSize.x, _prevDisplaySize.x);
-            Callbacks.ApplyMipmapBias(-biasOffset);
-            
+            if (!float.IsNaN(biasOffset))
+            {
+                Callbacks.ApplyMipmapBias(-biasOffset);
+            }
+
             // Restore the camera's original state
             _renderCamera.depthTextureMode = _originalDepthTextureMode;
             _renderCamera.targetTexture = _originalRenderTarget;