move texture and model processing out of download thread and fix some normalization for weights

LightlessSync/Services/ModelDecimation/MdlDecimator.cs

@@ -2115,6 +2115,16 @@ internal static class MdlDecimator
             }
         }
 
+        if (boneWeights != null
+            && blendWeightEncoding == BlendWeightEncoding.Default
+            && format.BlendWeightsElement is { } blendWeightsElement
+            && (MdlFile.VertexType)blendWeightsElement.Type == MdlFile.VertexType.UShort4
+            && ShouldTreatWeightsAsByteNormalized(boneWeights))
+        {
+            RescaleUShortAsByteWeights(boneWeights);
+            blendWeightEncoding = BlendWeightEncoding.UShortAsByte;
+        }
+
         decoded = new DecodedMeshData(positions, normals, tangents, tangents2, colors, boneWeights, uvChannels, positionWs, normalWs, blendWeightEncoding);
         return true;
     }
@@ -3424,6 +3434,44 @@ internal static class MdlDecimator
         return ToUShortNormalized(normalized);
     }
 
+    private static bool ShouldTreatWeightsAsByteNormalized(BoneWeight[] weights)
+    {
+        const float maxByteUnorm = byte.MaxValue / (float)ushort.MaxValue;
+        var maxWeight = 0f;
+        for (var i = 0; i < weights.Length; i++)
+        {
+            var weight = weights[i];
+            maxWeight = Math.Max(maxWeight, weight.weight0);
+            maxWeight = Math.Max(maxWeight, weight.weight1);
+            maxWeight = Math.Max(maxWeight, weight.weight2);
+            maxWeight = Math.Max(maxWeight, weight.weight3);
+            if (maxWeight > maxByteUnorm)
+            {
+                return false;
+            }
+        }
+
+        return maxWeight > 0f;
+    }
+
+    private static void RescaleUShortAsByteWeights(BoneWeight[] weights)
+    {
+        var scale = ushort.MaxValue / (float)byte.MaxValue;
+        for (var i = 0; i < weights.Length; i++)
+        {
+            var weight = weights[i];
+            weights[i] = new BoneWeight(
+                weight.index0,
+                weight.index1,
+                weight.index2,
+                weight.index3,
+                weight.weight0 * scale,
+                weight.weight1 * scale,
+                weight.weight2 * scale,
+                weight.weight3 * scale);
+        }
+    }
+
     private static void NormalizeWeights(float[] weights)
     {
         var sum = weights.Sum();