diff --git a/thirdparty/README.md b/thirdparty/README.md
index 815c533645f..c98f5939203 100644
--- a/thirdparty/README.md
+++ b/thirdparty/README.md
@@ -4,7 +4,7 @@
 ## assimp
 
 - Upstream: http://github.com/assimp/assimp
-- Version: git (d2b45377e4b09a1f43be95e45553afcc06b03f4b)
+- Version: git (d3d98a7ec0c8d38e1952b46dfe53f7e9233dc92d)
 - License: BSD-3-Clause
 
 
diff --git a/thirdparty/assimp/code/FBXConverter.cpp b/thirdparty/assimp/code/FBXConverter.cpp
index 000c4ed53b9..09ae06a64fe 100644
--- a/thirdparty/assimp/code/FBXConverter.cpp
+++ b/thirdparty/assimp/code/FBXConverter.cpp
@@ -78,6 +78,16 @@ namespace Assimp {
 
         FBXConverter::FBXConverter(aiScene* out, const Document& doc)
             : defaultMaterialIndex()
+            , lights()
+            , cameras()
+            , textures()
+            , materials_converted()
+            , textures_converted()
+            , meshes_converted()
+            , node_anim_chain_bits()
+            , mNodeNameInstances()
+            , mNodeNames()
+            , anim_fps()
             , out(out)
             , doc(doc) {
             // animations need to be converted first since this will
@@ -410,19 +420,24 @@ namespace Assimp {
 
         void FBXConverter::GetUniqueName(const std::string &name, std::string &uniqueName)
         {
-            int i = 0;
             uniqueName = name;
-            while (mNodeNames.find(uniqueName) != mNodeNames.end())
+            int i = 0;
+            auto it = mNodeNameInstances.find(name); // duplicate node name instance count
+            if (it != mNodeNameInstances.end())
             {
-                ++i;
-                std::stringstream ext;
-                ext << name << std::setfill('0') << std::setw(3) << i;
-                uniqueName = ext.str();
+                i = it->second;
+                while (mNodeNames.find(uniqueName) != mNodeNames.end())
+                {
+                    i++;
+                    std::stringstream ext;
+                    ext << name << std::setfill('0') << std::setw(3) << i;
+                    uniqueName = ext.str();
+                }
             }
+            mNodeNameInstances[name] = i;
             mNodeNames.insert(uniqueName);
         }
 
-
         const char* FBXConverter::NameTransformationComp(TransformationComp comp) {
             switch (comp) {
             case TransformationComp_Translation:
@@ -2041,6 +2056,12 @@ namespace Assimp {
                 CalculatedOpacity = 1.0f - ((Transparent.r + Transparent.g + Transparent.b) / 3.0f);
             }
 
+            // try to get the transparency factor
+            const float TransparencyFactor = PropertyGet<float>(props, "TransparencyFactor", ok);
+            if (ok) {
+                out_mat->AddProperty(&TransparencyFactor, 1, AI_MATKEY_TRANSPARENCYFACTOR);
+            }
+
             // use of TransparencyFactor is inconsistent.
             // Maya always stores it as 1.0,
             // so we can't use it to set AI_MATKEY_OPACITY.
diff --git a/thirdparty/assimp/code/FBXConverter.h b/thirdparty/assimp/code/FBXConverter.h
index 398baa445f2..50637468b91 100644
--- a/thirdparty/assimp/code/FBXConverter.h
+++ b/thirdparty/assimp/code/FBXConverter.h
@@ -58,6 +58,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/texture.h>
 #include <assimp/camera.h>
 #include <assimp/StringComparison.h>
+#include <unordered_map>
+#include <unordered_set>
 
 struct aiScene;
 struct aiNode;
@@ -74,8 +76,6 @@ namespace FBX {
 
 class Document;
 
-using NodeNameCache = std::set<std::string>;
-
 /** 
  *  Convert a FBX #Document to #aiScene
  *  @param out Empty scene to be populated
@@ -419,7 +419,6 @@ private:
     void TransferDataToScene();
 
 private:
-
     // 0: not assigned yet, others: index is value - 1
     unsigned int defaultMaterialIndex;
 
@@ -429,22 +428,27 @@ private:
     std::vector<aiLight*> lights;
     std::vector<aiCamera*> cameras;
     std::vector<aiTexture*> textures;
-    
 
-    typedef std::map<const Material*, unsigned int> MaterialMap;
+    using MaterialMap = std::map<const Material*, unsigned int>;
     MaterialMap materials_converted;
 
-    typedef std::map<const Video*, unsigned int> VideoMap;
+    using VideoMap = std::map<const Video*, unsigned int>;
     VideoMap textures_converted;
 
-    typedef std::map<const Geometry*, std::vector<unsigned int> > MeshMap;
+    using MeshMap = std::map<const Geometry*, std::vector<unsigned int> >;
     MeshMap meshes_converted;
 
     // fixed node name -> which trafo chain components have animations?
-    typedef std::map<std::string, unsigned int> NodeAnimBitMap;
+    using NodeAnimBitMap = std::map<std::string, unsigned int> ;
     NodeAnimBitMap node_anim_chain_bits;
 
+    // number of nodes with the same name
+    using NodeAnimNameMap = std::unordered_map<std::string, unsigned int>;
+    NodeAnimNameMap mNodeNameInstances;
+
+    using NodeNameCache = std::unordered_set<std::string>;
     NodeNameCache mNodeNames;
+
     double anim_fps;
 
     aiScene* const out;
diff --git a/thirdparty/assimp/code/FBXMaterial.cpp b/thirdparty/assimp/code/FBXMaterial.cpp
index 08347740faf..f16f1344042 100644
--- a/thirdparty/assimp/code/FBXMaterial.cpp
+++ b/thirdparty/assimp/code/FBXMaterial.cpp
@@ -55,6 +55,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/ByteSwapper.h>
 
 #include <algorithm> // std::transform
+#include "FBXUtil.h"
 
 namespace Assimp {
 namespace FBX {
@@ -206,6 +207,20 @@ Texture::Texture(uint64_t id, const Element& element, const Document& doc, const
 
     props = GetPropertyTable(doc,"Texture.FbxFileTexture",element,sc);
 
+    // 3DS Max and FBX SDK use "Scaling" and "Translation" instead of "ModelUVScaling" and "ModelUVTranslation". Use these properties if available.
+    bool ok;
+    const aiVector3D& scaling = PropertyGet<aiVector3D>(*props, "Scaling", ok);
+    if (ok) {
+        uvScaling.x = scaling.x;
+        uvScaling.y = scaling.y;
+    }
+
+    const aiVector3D& trans = PropertyGet<aiVector3D>(*props, "Translation", ok);
+    if (ok) {
+        uvTrans.x = trans.x;
+        uvTrans.y = trans.y;
+    }
+
     // resolve video links
     if(doc.Settings().readTextures) {
         const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID());
@@ -307,7 +322,22 @@ Video::Video(uint64_t id, const Element& element, const Document& doc, const std
             const Token& token = GetRequiredToken(*Content, 0);
             const char* data = token.begin();
             if (!token.IsBinary()) {
-                DOMWarning("video content is not binary data, ignoring", &element);
+                if (*data != '"') {
+                    DOMError("embedded content is not surrounded by quotation marks", &element);
+                }
+                else {
+                    const char* encodedData = data + 1;
+                    size_t encodedDataLen = static_cast<size_t>(token.end() - token.begin());
+                    // search for last quotation mark
+                    while (encodedDataLen > 1 && encodedData[encodedDataLen] != '"')
+                        encodedDataLen--;
+                    if (encodedDataLen % 4 != 0) {
+                        DOMError("embedded content is invalid, needs to be in base64", &element);
+                    }
+                    else {
+                        contentLength = Util::DecodeBase64(encodedData, encodedDataLen, content);
+                    }
+                }
             }
             else if (static_cast<size_t>(token.end() - data) < 5) {
                 DOMError("binary data array is too short, need five (5) bytes for type signature and element count", &element);
diff --git a/thirdparty/assimp/code/FBXUtil.cpp b/thirdparty/assimp/code/FBXUtil.cpp
index c184c4a00b7..fb483161b2a 100644
--- a/thirdparty/assimp/code/FBXUtil.cpp
+++ b/thirdparty/assimp/code/FBXUtil.cpp
@@ -49,6 +49,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <assimp/TinyFormatter.h>
 #include <string>
+#include <cstring>
 
 #ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
 
@@ -113,6 +114,49 @@ std::string AddTokenText(const std::string& prefix, const std::string& text, con
         text) );
 }
 
+static const uint8_t base64DecodeTable[128] = {
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 62,  0,  0,  0, 63,
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61,  0,  0,  0, 64,  0,  0,
+    0,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,  0,  0,  0,  0,  0,
+    0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,  0,  0,  0,  0,  0
+};
+
+uint8_t DecodeBase64(char ch)
+{
+    return base64DecodeTable[size_t(ch)];
+}
+
+size_t DecodeBase64(const char* in, size_t inLength, uint8_t*& out)
+{
+    if (inLength < 4) {
+        out = 0;
+        return 0;
+    }
+
+    const size_t outLength = (inLength * 3) / 4;
+    out = new uint8_t[outLength];
+    memset(out, 0, outLength);
+
+    size_t i = 0;
+    size_t j = 0;
+    for (i = 0; i < inLength - 4; i += 4)
+    {
+        uint8_t b0 = Util::DecodeBase64(in[i]);
+        uint8_t b1 = Util::DecodeBase64(in[i + 1]);
+        uint8_t b2 = Util::DecodeBase64(in[i + 2]);
+        uint8_t b3 = Util::DecodeBase64(in[i + 3]);
+
+        out[j++] = (uint8_t)((b0 << 2) | (b1 >> 4));
+        out[j++] = (uint8_t)((b1 << 4) | (b2 >> 2));
+        out[j++] = (uint8_t)((b2 << 6) | b3);
+    }
+    return outLength;
+}
+
 } // !Util
 } // !FBX
 } // !Assimp
diff --git a/thirdparty/assimp/code/FBXUtil.h b/thirdparty/assimp/code/FBXUtil.h
index 1a37d346b4f..6890e015bab 100644
--- a/thirdparty/assimp/code/FBXUtil.h
+++ b/thirdparty/assimp/code/FBXUtil.h
@@ -48,6 +48,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "FBXCompileConfig.h"
 #include "FBXTokenizer.h"
+#include <stdint.h>
 
 namespace Assimp {
 namespace FBX {
@@ -98,6 +99,20 @@ std::string AddLineAndColumn(const std::string& prefix, const std::string& text,
  *  @return A string of the following format: {prefix} ({token-type}, line {line}, col {column}) {text}*/
 std::string AddTokenText(const std::string& prefix, const std::string& text, const Token* tok);
 
+/** Decode a single Base64-encoded character.
+*
+*  @param ch Character to decode (from base64 to binary).
+*  @return decoded byte value*/
+uint8_t DecodeBase64(char ch);
+
+/** Decode a Base64-encoded string
+*
+*  @param in Characters to decode.
+*  @param inLength Number of characters to decode.
+*  @param out Reference to pointer where we will store the decoded data.
+*  @return size of the decoded data (number of bytes)*/
+size_t DecodeBase64(const char* in, size_t inLength, uint8_t*& out);
+
 }
 }
 }
diff --git a/thirdparty/assimp/code/Version.cpp b/thirdparty/assimp/code/Version.cpp
index cc94340ac80..0381037ff1a 100644
--- a/thirdparty/assimp/code/Version.cpp
+++ b/thirdparty/assimp/code/Version.cpp
@@ -134,7 +134,7 @@ ASSIMP_API aiScene::aiScene()
 , mCameras(nullptr)
 , mMetaData(nullptr)
 , mPrivate(new Assimp::ScenePrivateData()) {
-	// empty
+    // empty
 }
 
 // ------------------------------------------------------------------------------------------------
diff --git a/thirdparty/assimp/include/assimp/material.h b/thirdparty/assimp/include/assimp/material.h
index b882bbc72cf..4b5a1293ddf 100644
--- a/thirdparty/assimp/include/assimp/material.h
+++ b/thirdparty/assimp/include/assimp/material.h
@@ -900,6 +900,7 @@ extern "C" {
 #define AI_MATKEY_ENABLE_WIREFRAME "$mat.wireframe",0,0
 #define AI_MATKEY_BLEND_FUNC "$mat.blend",0,0
 #define AI_MATKEY_OPACITY "$mat.opacity",0,0
+#define AI_MATKEY_TRANSPARENCYFACTOR "$mat.transparencyfactor",0,0
 #define AI_MATKEY_BUMPSCALING "$mat.bumpscaling",0,0
 #define AI_MATKEY_SHININESS "$mat.shininess",0,0
 #define AI_MATKEY_REFLECTIVITY "$mat.reflectivity",0,0