Build-compatible and configurable tendon rendering for Unity

unity/Editor/Components/MjTendonRendererEditor.cs

@@ -0,0 +1,96 @@
+// Copyright 2019 DeepMind Technologies Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using UnityEditor;
+using UnityEngine;
+
+namespace Mujoco {
+
+[CustomEditor(typeof(MjTendonRenderer))]
+public class MjTendonRendererEditor : Editor {
+
+  public override void OnInspectorGUI() {
+    DrawDefaultInspector();
+    var mjTendonRenderer = (MjTendonRenderer)target;
+    EditorGUILayout.Space(10);
+
+    if (GUILayout.Button("Add Line Renderers")) {
+      ConfigureLineRenderers(mjTendonRenderer);
+    }
+    EditorGUILayout.Space(5);
+    if (GUILayout.Button("Update Rendered Line Positions")) {
+      UpdateRenderedTendons(mjTendonRenderer);
+    }
+    EditorGUILayout.Space(10);
+  }
+
+  private unsafe void ConfigureLineRenderers(MjTendonRenderer mjTendonRenderer) {
+    if (mjTendonRenderer.SpatialTendons == null || mjTendonRenderer.SpatialTendons.Length == 0) {
+      Debug.LogWarning("LineRendererSetup: No target GameObjects assigned in the list.", mjTendonRenderer);
+      return;
+    }
+
+    Undo.SetCurrentGroupName("Configure Line Renderers");
+    var group = Undo.GetCurrentGroup();
+
+    foreach (var tendon in mjTendonRenderer.SpatialTendons) {
+      var lr = tendon.GetComponent<LineRenderer>();
+
+      if (lr != null) {
+        if (!mjTendonRenderer.LineRendererDefaults.OverwriteExisting) {
+          continue;
+        }
+        Undo.RecordObject(lr, "Configure Existing Line Renderer");
+        ApplySettings(lr, tendon, mjTendonRenderer.LineRendererDefaults);
+      } else {
+        lr = Undo.AddComponent<LineRenderer>(tendon.gameObject);
+        ApplySettings(lr, tendon, mjTendonRenderer.LineRendererDefaults);
+      }
+    }
+    UpdateRenderedTendons(mjTendonRenderer);
+    Undo.CollapseUndoOperations(group);
+  }
+
+  private unsafe void UpdateRenderedTendons(MjTendonRenderer mjTendonRenderer) {
+    Undo.IncrementCurrentGroup();
+    Undo.SetCurrentGroupName("Update Rendered Tendons");
+    var group = Undo.GetCurrentGroup();
+    MjScene.Instance.CreateScene();
+    var model = MjScene.Instance.Model;
+    var data = MjScene.Instance.Data;
+    MujocoLib.mj_forward(model, data);
+    var renderedTendons = mjTendonRenderer.RenderedTendons;
+    foreach ((var _, LineRenderer lr) in renderedTendons) {
+      Undo.RecordObject(lr, "Update Tendon's Line Renderer");
+    }
+    mjTendonRenderer.UpdateTendons(this, new MjStepArgs(model, data), renderedTendons);
+    DestroyImmediate(MjScene.Instance.gameObject);
+    Undo.CollapseUndoOperations(group);
+  }
+
+  private void ApplySettings(LineRenderer lineRenderer, MjSpatialTendon tendon,
+      MjTendonRenderer.TendonRenderingDefaults settings) {
+    lineRenderer.material = settings.DefaultMaterial;
+    lineRenderer.startColor = settings.DefaultColor;
+    lineRenderer.endColor = settings.DefaultColor;
+    lineRenderer.useWorldSpace = true;
+    lineRenderer.numCapVertices = settings.NumVertices;
+    lineRenderer.numCornerVertices = settings.NumVertices;
+    lineRenderer.generateLightingData = settings.GenerateLightingData;
+    if (settings.ScaleByWidth) {
+      lineRenderer.widthMultiplier = tendon.Width * settings.WidthMultiplier;
+    }
+  }
+}
+}

unity/Runtime/Components/Tendons/MjTendonRenderer.cs

@@ -0,0 +1,108 @@
+// Copyright 2019 DeepMind Technologies Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine;
+
+namespace Mujoco {
+
+public class MjTendonRenderer : MonoBehaviour {
+
+  // We serialize these to give the option to remove tendons from the list of rendered tendons
+  [SerializeField]
+  public MjSpatialTendon[] SpatialTendons;
+
+  // If a tendon does not have an attached LineRenderer, we don't update it, so this may be a
+  // subset of _spatialTendons
+  private (MjSpatialTendon, LineRenderer)[] _renderedTendons;
+
+  [SerializeField]
+  public TendonRenderingDefaults LineRendererDefaults;
+
+  public (MjSpatialTendon, LineRenderer)[] RenderedTendons {
+    get {
+      return SpatialTendons
+          .Where(st => st.GetComponent<LineRenderer>())
+          .Select(st => st.GetComponent<LineRenderer>())
+          .Select(lr => (lr.GetComponent<MjSpatialTendon>(), lr))
+          .ToArray();
+    }
+  }
+
+  void Reset() {
+    SpatialTendons = GetComponentsInChildren<MjSpatialTendon>();
+  }
+
+  void Start() {
+    _renderedTendons = RenderedTendons;
+    MjScene.Instance.postUpdateEvent +=
+        (sender, args) => UpdateTendons(sender, args, _renderedTendons);
+  }
+
+  public unsafe void UpdateTendons(object sender, MjStepArgs args,
+      (MjSpatialTendon, LineRenderer)[] renderedTendons) {
+    var d = args.data;
+    var m = args.model;
+    foreach (var (tendon, renderer) in renderedTendons) {
+      int i = tendon.MujocoId;
+      List<Vector3> positions = new List<Vector3>();
+      double sz;
+
+      for (int j = d->ten_wrapadr[i]; j < d->ten_wrapadr[i] + d->ten_wrapnum[i]; j++) {
+        // Skip drawing of pulley (-2):
+        if (d->wrap_obj[j] != -2 && d->wrap_obj[j + 1] != -2) {
+          // TODO: Consider handling of wrapping segments
+          /*if (d->wrap_obj[j] >= 0 && d->wrap_obj[j + 1] >= 0) {
+            sz = 0.5 * m->tendon_width[i];
+          } else {
+            sz = m->tendon_width[i];
+          }*/
+
+          positions.Add(MjEngineTool.UnityVector3(d->wrap_xpos + 3 * j));
+        }
+      }
+      renderer.positionCount = positions.Count;
+      renderer.SetPositions(positions.ToArray());
+    }
+  }
+
+  [Serializable]
+  public class TendonRenderingDefaults {
+
+    [SerializeField]
+    public Color DefaultColor;
+
+    [SerializeField]
+    public Material DefaultMaterial;
+
+    [SerializeField]
+    public bool OverwriteExisting;
+
+    [SerializeField]
+    public int NumVertices = 12;
+
+    [SerializeField]
+    public bool ScaleByWidth;
+
+    [SerializeField]
+    public float WidthMultiplier = 1;
+
+    [SerializeField]
+    public bool GenerateLightingData;
+
+  }
+}
+}