From d5f647a2211f10b872979963226c66780c1efa92 Mon Sep 17 00:00:00 2001
From: Chris Want <cwant@ualberta.ca>
Date: Mon, 6 Oct 2008 17:06:13 +0000
Subject: [PATCH] A fix for bug #8814:
 http://projects.blender.org/tracker/?func=detail&atid=125&aid=8814&group_id=9

Smarter handling of faces that have a material index that points
to a null material.
---
 release/scripts/vrml97_export.py | 94 +++++++++++++++++++++-----------
 1 file changed, 62 insertions(+), 32 deletions(-)

diff --git a/release/scripts/vrml97_export.py b/release/scripts/vrml97_export.py
index b28c7f5bbdc..6ec05495327 100644
--- a/release/scripts/vrml97_export.py
+++ b/release/scripts/vrml97_export.py
@@ -556,31 +556,28 @@ class VRML2Export:
 		issmooth = 0
 
 		maters = me.materials
-		nummats = self.getNumMaterials(me)
+		nummats = len(me.materials)
 
 		# Vertex and Face colors trump materials and image textures
 		if (self.facecolors or self.vcolors):
 			if nummats > 0:
-				if maters[0]:
-					self.writeShape(ob, me, 0, None)
-				else:
-					self.writeShape(ob, me, -1, None)
+				self.writeShape(ob, me, 0, None)
 			else:
 				self.writeShape(ob, me, -1, None)
-		# Do meshes with materials, possible with image textures
+
+		# Do meshes with materials, possibly with image textures
 		elif nummats > 0:
 			for matnum in range(len(maters)):
-				if maters[matnum]:
-					images = []
-					if me.faceUV:
-						images = self.getImages(me, matnum)
-						if len(images) > 0:
-							for image in images:
-								self.writeShape(ob, me, matnum, image)
-						else:
-							self.writeShape(ob, me, matnum, None)
+				images = []
+				if me.faceUV:
+					images = self.getImages(me, matnum)
+					if len(images) > 0:
+						for image in images:
+							self.writeShape(ob, me, matnum, image)
 					else:
 						self.writeShape(ob, me, matnum, None)
+				else:
+					self.writeShape(ob, me, matnum, None)
 		else:
 			if me.faceUV:
 				images = self.getImages(me, -1)
@@ -608,15 +605,6 @@ class VRML2Export:
 						imageNames[imName]=1
 		return images
 
-	def getNumMaterials(self, me):
-		# Oh silly Blender, why do you sometimes have 'None' as
-		# a member of the me.materials array?
-		num = 0
-		for mat in me.materials:
-			if mat:
-				num = num + 1
-		return num
-
 	def writeCoordinates(self, me, meshName):
 		coordName = "coord_%s" % (meshName)
 		# look up coord name, use it if available
@@ -644,20 +632,43 @@ class VRML2Export:
 		self.writeIndented("}\n", -1)
 		self.writeIndented("\n")
 
+	def testShape(self, ob, me, matnum, image):
+		if ( (matnum == -1) and (image == None) ):
+			if ( len(me.faces) > 0 ):
+				return True
+		# Check if any faces the material or image
+		for face in me.faces:
+			if (matnum == -1):
+				if (f.image == image):
+					return True
+			elif (image == None):
+				if (face.mat == matnum):
+					return True
+			else:
+				if ((face.image == image) and (face.mat == matnum)):
+					return True
+
+		return False
+
 	def writeShape(self, ob, me, matnum, image):
-		# Note: at this point it is assumed for matnum!=-1 that the 
-		# material in me.materials[matnum] is not equal to 'None'.
-		# Such validation should be performed by the function that
-		# calls this one.
+		# matnum == -1  means don't check the face.mat
+		# image == None means don't check face.image
+
+		if ( not self.testShape(ob, me, matnum, image) ):
+			return False
+
 		self.writeIndented("Shape {\n",1)
 
 		self.writeIndented("appearance Appearance {\n", 1)
 		if (matnum != -1):
 			mater = me.materials[matnum]
-			self.writeMaterial(mater, self.cleanStr(mater.name,''))
-			if (mater.mode & Blender.Material.Modes['TEXFACE']):
-				if image != None:
-					self.writeImageTexture(image.name, image.filename)
+			if (mater):
+				self.writeMaterial(mater, self.cleanStr(mater.name,''))
+				if (mater.mode & Blender.Material.Modes['TEXFACE']):
+					if image != None:
+						self.writeImageTexture(image.name, image.filename)
+			else:
+				self.writeDefaultMaterial()	
 		else:
 			if image != None:
 				self.writeImageTexture(image.name, image.filename)
@@ -668,6 +679,8 @@ class VRML2Export:
 
 		self.writeIndented("}\n", -1)
 
+		return True
+
 	def writeGeometry(self, ob, me, matnum, image):
 
 		#-- IndexedFaceSet or IndexedLineSet
@@ -784,6 +797,23 @@ class VRML2Export:
 		self.writeIndented("]\n",-1)
 		self.writeIndented("}\n",-1)
 
+	def writeDefaultMaterial(self):
+		matName = "default"
+
+		# look up material name, use it if available
+		if self.matNames.has_key(matName):
+			self.writeIndented("material USE MA_%s\n" % matName)
+			self.matNames[matName]+=1
+			return;
+
+		self.matNames[matName]=1
+		self.writeIndented("material DEF MA_%s Material {\n" % matName, 1)
+		self.writeIndented("diffuseColor 0.8 0.8 0.8\n")
+		self.writeIndented("specularColor 1.0 1.0 1.0\n")
+		self.writeIndented("shininess 0.5\n")
+		self.writeIndented("transparency 0.0\n")
+		self.writeIndented("}\n",-1)
+
 	def writeMaterial(self, mat, matName):
 		# look up material name, use it if available
 		if self.matNames.has_key(matName):
-- 
2.28.0