Change various network variables in asset editor.

ChangeNetworkVariables_AssetEditor.cs

var asset = ToolsModifierControl.toolController.m_editPrefabInfo as NetInfo;

// change half width
asset.m_halfWidth = 22.0f;

// enable create pavement
asset.m_createPavement = true;

// change the color of basic segment 0
var color = new Color32(255, 0, 0, 255);
asset.m_segments[0].m_material.SetColor("_Color", color);

// change the color of elevated segment 0
var color2 = new Color32(0, 255, 0, 255);
(asset.m_netAI.GetType().GetField("m_elevatedInfo").GetValue(asset.m_netAI) as NetInfo).m_segments[0].m_material.SetColor("_Color", color2);

// refresh UI and built network
typeof(RoadEditorMainPanel).GetMethod("Clear", BindingFlags.NonPublic | BindingFlags.Instance).Invoke(UnityEngine.Object.FindObjectOfType<RoadEditorMainPanel>(), null);
typeof(RoadEditorMainPanel).GetMethod("Initialize", BindingFlags.NonPublic | BindingFlags.Instance).Invoke(UnityEngine.Object.FindObjectOfType<RoadEditorMainPanel>(), null);
typeof(RoadEditorPanel).GetMethod("OnObjectModified", BindingFlags.NonPublic | BindingFlags.Instance).Invoke(UnityEngine.Object.FindObjectOfType<RoadEditorPanel>(), null);