Get decal switching working mostly

Distribution/GameData/ConformalDecals/Parts/decal-blank.cfg

@@ -47,22 +47,58 @@ PART
 
     decalFront = Decal-Front
     decalBack = Decal-Back
-    decalShader = ConformalDecals/Feature/Bumped
 
     useBaseNormal = false
 
-    TEXTURE
-    {
-      name = _Decal
-      textureURL = ConformalDecals/Assets/Tortilla-diffuse
-      isMain = true
+
+  }
+
+  MODULE {
+    name = ModuleB9PartSwitch
+
+    SUBTYPE {
+      name = tortilla
+
+      MODULE {
+        IDENTIFIER {
+          name = ModuleConformalDecal
+        }
+        DATA {
+          decalShader = ConformalDecals/Feature/Bumped
+
+          TEXTURE {
+            name = _Decal
+            textureURL = ConformalDecals/Assets/Tortilla-diffuse
+            isMain = true
+          }
+
+          TEXTURE
+          {
+            name = _BumpMap
+            textureURL = ConformalDecals/Assets/Tortilla-normal
+            isNormalMap = true
+          }
+        }
+      }
     }
 
-    TEXTURE
-    {
-      name = _BumpMap
-      textureURL = ConformalDecals/Assets/Tortilla-normal
-      isNormalMap = true
+    SUBTYPE {
+      name = Danger
+
+      MODULE {
+        IDENTIFIER {
+          name = ModuleConformalDecal
+        }
+        DATA {
+          decalShader = ConformalDecals/Paint/Diffuse
+          useBaseNormal = true
+          TEXTURE {
+            name = _Decal
+            textureURL = ConformalDecals/Assets/Sign-HighVoltage-2
+            isMain = true
+          }
+        }
+      }
     }
   }
 }

Source/ConformalDecals/MaterialModifiers/MaterialPropertyCollection.cs

@@ -31,6 +31,12 @@ namespace ConformalDecals.MaterialModifiers {
         }
 
         public void AddProperty(MaterialProperty property) {
+            if (property == null) throw new ArgumentNullException("Tried to add a null property");
+            if (_materialProperties == null || _textureMaterialProperties == null) {
+                Initialize();
+                Debug.LogWarning("Tried to add a property to uninitialized property collection! correcting now.");
+            }
+            
             foreach (var p in _materialProperties) {
                 if (p.PropertyName == property.PropertyName) {
                     _materialProperties.Remove(property);
@@ -53,8 +59,14 @@ namespace ConformalDecals.MaterialModifiers {
         }
 
         public void SetShader(string shaderName) {
-            if (_decalShader == null && string.IsNullOrEmpty(shaderName)) {
-                throw new FormatException("Shader name not provided");
+            if (string.IsNullOrEmpty(shaderName)) {
+                if (_decalShader == null) {
+                    Debug.Log("Using default decal shader");
+                    shaderName = "ConformalDecals/Paint/Diffuse";
+                }
+                else {
+                    return;
+                }
             }
 
             var shader = Shabby.Shabby.FindShader(shaderName);

Source/ConformalDecals/ModuleConformalDecal.cs

@@ -29,7 +29,7 @@ namespace ConformalDecals {
         [KSPField] public string decalBack      = string.Empty;
         [KSPField] public string decalModel     = string.Empty;
         [KSPField] public string decalProjector = string.Empty;
-        [KSPField] public string decalShader    = string.Empty;
+        [KSPField] public string decalShader    = "ConformalDecals/Paint/Diffuse";
 
         [KSPField] public Transform decalFrontTransform;
         [KSPField] public Transform decalBackTransform;
@@ -93,6 +93,7 @@ namespace ConformalDecals {
                 }
                 else {
                     // materialProperties already exists, so make a copy
+                    this.Log($"{materialProperties == null}");
                     materialProperties = ScriptableObject.Instantiate(materialProperties);
                 }
 

Source/ConformalDecals/ProjectionTarget.cs

@@ -1,5 +1,3 @@
-using System;
-using ConformalDecals.MaterialModifiers;
 using ConformalDecals.Util;
 using UnityEngine;
 using UnityEngine.Rendering;