Unity Blender Decimate

Author: AlexeyTaranov

Decimate.py

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+import bpy
+import sys
+
+argv = sys.argv
+#Get only our arguments
+argv = argv[argv.index("--") + 1:]
+print(argv)
+objPath = argv[0]
+decimateValue = argv[1]
+
+#Delete default objects:cube,camera,light
+bpy.ops.object.select_all(action='SELECT')
+bpy.ops.object.delete(use_global=False)
+
+imported_object = bpy.ops.import_scene.obj(filepath=objPath)
+obj_object = bpy.context.selected_objects[0]
+decimate = obj_object.modifiers.new(name="Decimate", type = 'DECIMATE')
+decimate.ratio = float(decimateValue)
+
+#Export as obj
+bpy.ops.export_scene.obj(filepath=objPath)

Decimate.py.meta

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+using System;
+using System.Diagnostics;
+using System.IO;
+using UnityEditor;
+using UnityEditor.UIElements;
+using UnityEngine;
+using UnityEngine.UIElements;
+using Object = UnityEngine.Object;
+
+namespace Editor.UnityBlenderDecimate
+{
+    public class UnityBlenderDecimate : EditorWindow
+    {
+        [MenuItem("Tools/Unity To Blender")]
+        public static void ShowExample()
+        {
+            UnityBlenderDecimate window = GetWindow<UnityBlenderDecimate>();
+            window.titleContent = new GUIContent("Unity Blender Decimate");
+        }
+
+        [SerializeField] private VisualTreeAsset visualTreeAsset;
+        [SerializeField] private string blenderPath;
+        private Button BlenderPathSelectButton => rootVisualElement.Q<Button>("blenderPathSelect");
+        private Label BlenderPathLabel => rootVisualElement.Q<Label>("blenderPath");
+        private ObjectField PythonScriptField => rootVisualElement.Q<ObjectField>("pythonScript");
+        private ObjectField InputObject => rootVisualElement.Q<ObjectField>("inputObject");
+
+        private GameObject selectedGameObject;
+        private string pythonScriptPath;
+
+        public void CreateGUI()
+        {
+            rootVisualElement.Add(visualTreeAsset.Instantiate());
+#if UNITY_EDITOR_OSX
+            SetupOSXBlenderPath();
+#else
+            BlenderPathSelectButton.RegisterCallback<ClickEvent>(OnBlenderSelectPathClick);
+#endif
+
+            PythonScriptField.RegisterValueChangedCallback(OnPythonScriptSelect);
+            InputObject.RegisterValueChangedCallback(CheckSelectedInputObject);
+            rootVisualElement.Q<Button>("execute").RegisterCallback<ClickEvent>(Execute);
+            
+            UpdateNextStep();
+        }
+
+        private void SetupOSXBlenderPath()
+        {
+            BlenderPathSelectButton.SetEnabled(false);
+            BlenderPathLabel.text = IsAvailableBlender() ? blenderPath : "Can't find Blender in Applications folder =(";
+
+            bool IsAvailableBlender()
+            {
+                blenderPath = Path.Combine("/Applications", "Blender.app", "Contents", "MacOS", "Blender");
+                return File.Exists(blenderPath);
+            }
+        }
+
+        private void UpdateNextStep()
+        {
+            Func<(bool isValidStep, string stepName)>[] steps =
+            {
+                () => (File.Exists(blenderPath), "blenderPathStep"),
+                () => (string.IsNullOrEmpty(pythonScriptPath) == false, "pythonScript"),
+                () => (selectedGameObject != null, "inputObjectStep"),
+                () => (true, "blenderExecuteStep")
+            };
+
+            var failedStep = Array.FindIndex(steps, func => func.Invoke().isValidStep == false);
+            for (var i = 0; i < steps.Length; i++)
+            {
+                var stepName = steps[i].Invoke().stepName;
+                var element = rootVisualElement.Q<VisualElement>(stepName);
+                element?.SetEnabled(failedStep >= i || failedStep == -1);
+            }
+        }
+
+        private void OnBlenderSelectPathClick(ClickEvent @event)
+        {
+            var path = string.IsNullOrEmpty(blenderPath) ? Application.dataPath : blenderPath;
+            var executableExtension = "exe";
+            blenderPath = EditorUtility.OpenFilePanel("Select Blender executable", path, executableExtension);
+            BlenderPathLabel.text = blenderPath;
+            
+            UpdateNextStep();
+        }
+
+        private void OnPythonScriptSelect(ChangeEvent<Object> @event)
+        {
+            var path = AssetDatabase.GetAssetPath(@event.newValue);
+            pythonScriptPath = Path.GetExtension(path) == ".py" ? Path.GetFullPath(path) : null;
+            
+            UpdateNextStep();
+        }
+
+        private void CheckSelectedInputObject(ChangeEvent<Object> @event)
+        {
+            PrefabAssetType prefabType = PrefabAssetType.NotAPrefab;
+            var go = @event.newValue as GameObject;
+            if (go != null)
+            {
+                var prefabAssetType = PrefabUtility.GetPrefabAssetType(go);
+                var fileExtension = Path.GetExtension(AssetDatabase.GetAssetPath(go));
+                var isObjModel = prefabAssetType == PrefabAssetType.Model && fileExtension == ".obj";
+                prefabType = isObjModel ? PrefabAssetType.Model : PrefabAssetType.NotAPrefab;
+            }
+            selectedGameObject = prefabType == PrefabAssetType.Model ? go : null;
+            InputObject.value = selectedGameObject;
+
+            UpdateNextStep();
+        }
+
+        private void Execute(ClickEvent @event)
+        {
+            var decimateValue = rootVisualElement.Q<Slider>("decimate").value;
+            var absolutePathToObj = Path.GetFullPath(AssetDatabase.GetAssetPath(selectedGameObject));
+            absolutePathToObj = '"' + absolutePathToObj + '"';
+            var blenderProcess = new Process();
+            blenderProcess.StartInfo.FileName = blenderPath;
+            var bgBlenderArgs = $"--background --python {pythonScriptPath} -- {absolutePathToObj} {decimateValue}";
+            blenderProcess.StartInfo.Arguments = bgBlenderArgs;
+            blenderProcess.Start();
+            //TODO: Don't lock Unity
+            blenderProcess.WaitForExit();
+            AssetDatabase.Refresh(ImportAssetOptions.ForceUpdate);
+        }
+    }
+}

UnityBlenderDecimate.cs

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+<ui:UXML xmlns:ui="UnityEngine.UIElements" xmlns:uie="UnityEditor.UIElements" engine="UnityEngine.UIElements" editor="UnityEditor.UIElements" editor-extension-mode="True">
+    <ui:Label text="Unity Blender Decimate" style="-unity-text-align: upper-center; font-size: 20px; -unity-font-style: bold;" />
+    <ui:VisualElement style="height: 4px; width: 504px;" />
+    <ui:VisualElement name="blenderPathStep" style="flex-direction: row;">
+        <ui:Button name="blenderPathSelect" text="Edit Blender Path" />
+        <ui:Label name="blenderPath" style="-unity-text-align: middle-left;" />
+    </ui:VisualElement>
+    <uie:ObjectField label="Python Script" name="pythonScript" type="UnityEditor.DefaultAsset, UnityEditor.CoreModule" />
+    <ui:VisualElement name="inputObjectStep">
+        <uie:ObjectField name="inputObject" label="OBJ Model" type="UnityEngine.GameObject, UnityEngine.CoreModule" allow-scene-objects="false" />
+    </ui:VisualElement>
+    <ui:VisualElement name="blenderExecuteStep">
+        <ui:Slider name="decimate" label="Decimate" value="1" high-value="1" show-input-field="true" />
+        <ui:Button name="execute" text="Run" display-tooltip-when-elided="true" />
+    </ui:VisualElement>
+</ui:UXML>