diff --git a/docs/documentation/building_a_simulation/Model-Source-Code.md b/docs/documentation/building_a_simulation/Model-Source-Code.md
index 896845a0..daa14373 100644
--- a/docs/documentation/building_a_simulation/Model-Source-Code.md
+++ b/docs/documentation/building_a_simulation/Model-Source-Code.md
@@ -408,24 +408,51 @@ Trick may use model code with any type of inheritance. Some limitations are pres
 
 ### Namespaces
 
-Currently one level of namespace is supported. Additional levels of namespaces are ignored. Similarly classes and enumerations embedded in other classes are ignored.
+ICG supports namespaces and nested scopes. Data recording and variable access via Trick View should work regardless of how many levels there are.
 
-```C++
-namespace my_ns {
-  // BB is processed
-  class BB {
-   public:
-    std::string str;
-    // Class CC is ignored.
-    class CC {
-      ...
+Namespaces and nested scopes are similarly supported in Python contexts, such as the input file and variable server, with some caveats regarding templates.
+1. A template instantiation may be unqualified (have no use of the scope resolution operator `::`) only if its corresponding template is declared in the immediately-enclosing namespace.
+2. Otherwise, a template instantiation must be fully qualified, starting from the global namespace.
+3. Finally, instantiations of templates declared within the same class must be excluded from SWIG.
+
+In the following examples, all template instantiations occur in `example::prime::Soup`. The immediately-enclosing namespace is `prime`, so only instantiations of templates declared directly in `prime` (only `Celery`) may be unqualified. All other template instantiations must be fully qualified, starting from the global namespace, even if the C++ name lookup process would find them with partial qualification.
+
+```c++
+template <class T> class Potato {};
+
+namespace example {
+
+  template <class T> class Onion {};
+
+  namespace peer {
+    template <class T> class Raddish {};
+  }
+
+  namespace prime {
+
+    namespace inner {
+        template <class T> class Carrot {};
     }
-  };
-  // Everything enclosed in inner_ns is ignored.
-  namespace inner_ns {
-    ...
-  };
-};
+
+    template <class T> class Celery {};
+
+    class Soup {
+
+      public:
+        template <class T> class Broth {};
+
+        ::Potato<int> potato;                      // Rule 2
+        example::Onion<int> onion;                 // Rule 2
+        example::peer::Raddish<int> raddish;       // Rule 2
+        example::prime::inner::Carrot<int> carrot; // Rule 2
+        Celery<int> celery;                        // Rule 1
+#ifndef SWIG
+        Broth<int> broth;                          // Rule 3
+#endif
+    };
+  }
+
+}
 ```
 
 ### Function Overloading
diff --git a/libexec/trick/convert_swig b/libexec/trick/convert_swig
index b7ffe9c9..a930a606 100755
--- a/libexec/trick/convert_swig
+++ b/libexec/trick/convert_swig
@@ -57,7 +57,6 @@ my %sim ;
 my %out_of_date ;
 my ($version, $thread, $year) ;
 my %processed_templates ;
-my $global_template_typedefs ;
 
 my $typedef_def = qr/typedef\s+                            # the word typedef
                (?:[_A-Za-z][\s\w]*\s*)                     # resolved type
@@ -336,7 +335,6 @@ sub process_file() {
         }
         print OUT "\n$new_contents" ;
         print OUT "$contents\n" ;
-        print OUT $global_template_typedefs ;
 
         # Add a trick_cast_as macro line for each class parsed in the file.  These lines must appear at the bottom of the
         # file to ensure they are not in a namespace directive and they are after the #define statements they depend on.
@@ -592,7 +590,8 @@ sub process_class($$$$$) {
 
     my $extracted ;
     my ($class_name) ;
-    my $template_typedefs ;
+    my @qualified_template_typedefs ;
+    my @unqualified_template_typedefs ;
 
 ## Extract the class_name from the class_string
     $class_string =~ /^(?:class|struct)\s+               # keyword class or struct
@@ -675,10 +674,6 @@ sub process_class($$$$$) {
                     my ($template_type_no_sp) = $template_full_type ;
                     $template_type_no_sp =~ s/\s//g ;
 
-                    # If the type is qualified, assume it's fully qualified and put the
-                    # %template directive in the global namespace.
-                    # See https://github.com/nasa/trick/issues/768
-                    my $qualified = $template_type_no_sp =~ /^\w+(::)\w+</ ;
                     #print "*** template_type_no_sp = $template_type_no_sp ***\n" ;
                     if ( ! exists $processed_templates{$template_type_no_sp} ) {
 
@@ -686,29 +681,48 @@ sub process_class($$$$$) {
                         my $identifier = "${sanitized_namespace}${class_name}_${var_name}" ;
                         my $trick_swig_template = "TRICK_SWIG_TEMPLATE_$identifier" ;
 
-                        # Insert template directive immediately before intsance
+                        # Insert template directive immediately before instance
                         # This is required as of SWIG 4
                         my $typedef = "\n#ifndef $trick_swig_template\n" ;
                         $typedef   .= "#define $trick_swig_template\n" ;
                         $typedef   .= "\%template($identifier) $template_full_type;\n" ;
                         $typedef   .= "#endif\n" ;
 
-                        # SWIG namespace resolution for template directives starts at the local space
-                        # Therefore, if the type is qualified, assume it's fully qualified and put the
-                        # %template directive in the global namespace by escaping the current namespace
-			if ($curr_namespace ne "") {
-                            my $in_same_namespace = 1 ;
-                            if ($template_full_type =~ /^\w*(::)\w+</) {
-                                $in_same_namespace = 0 ;
-                            }
-                            if ($in_same_namespace eq 0) {
-                                $curr_namespace =~ /(.*)::/ ;
-                                $typedef = "\n}" . $typedef . "namespace " . $1 . " {" ; 
-                            }
-                        }
+                        # A SWIG %template directive must:
+                        # 1. Appear before each template instantiation
+                        # 2. Be in scope where the instantiation is declared
+                        # 3. Not be enclosed within a different namespace
+                        #
+                        # See https://www.swig.org/Doc4.2/SWIGPlus.html#SWIGPlus_template_scoping
+                        #
+                        # Generally, convert_swig is not smart enough to put all %template
+                        # directives in the right scope because:
+                        # 1. We do not keep track of what scope each type we encounter is
+                        #    declared in.
+                        # 2. We cannot easily add %template directives to already-processed
+                        #    scopes.
+                        #
+                        # As a compromise:
+                        # 1. For an unqualified template instantiation, the template declaration
+                        #    is necessarily in the current or a containing scope. Hope it's in the
+                        #    current namespace and put the %template directive there. This will
+                        #    create invalid SWIG input code for templates declared in a containing
+                        #    namespace and for member templates declared in this class.
+                        # 2. For a qualified template instantiation, the template declaration is
+                        #    in a (possibly nested) scope contained by the current or a containing
+                        #    scope. Assume the instantiation is fully qualified and put it in the
+                        #    global namespace. This will create invalid SWIG code for partially-
+                        #    qualified instantiations.
+                        #
+                        # See https://github.com/nasa/trick/issues/768
 
                         if ($isSwigExcludeBlock == 0) {
-                            $template_typedefs .= $typedef ;
+                            if ($template_full_type =~ /^\w*(::\w+)+</) {
+                                push @qualified_template_typedefs, $typedef ;
+                            }
+                            else {
+                                push @unqualified_template_typedefs, $typedef ;
+                            }
                         }
 
                         $processed_templates{$template_type_no_sp} = 1 ;
@@ -721,12 +735,32 @@ sub process_class($$$$$) {
 
     push @$class_names_ref , "$curr_namespace$class_name" ;
 
-    # write out the templated variable declaration lines found in this class.
-    $$new_contents_ref .= $template_typedefs."\n" ;
+    # Write out the %template directives for template instantiations found in
+    # this class. Put the directives for unqualified instantiations in the
+    # namespace containing this class, just before the class definition.
+    foreach (@unqualified_template_typedefs) {
+        $$new_contents_ref .= $_ ;
+    }
+
+    # Assume qualified template instantiations are fully qualified and put
+    # their %template directives in the global namespace.
+    # 1. close all namespaces, returning to the global namespace
+    # 2. add the %template directives
+    # 3. open all namespaces, restoring the scope
+    if (@qualified_template_typedefs) {
+        my @namespaces = split(/::/, $curr_namespace) ;
+        $$new_contents_ref .= "}" x @namespaces . "\n";
+        foreach (@qualified_template_typedefs) {
+            $$new_contents_ref .= $_ ;
+        }
+        $$new_contents_ref .= "\n";
+        foreach (@namespaces) {
+            $$new_contents_ref .= "namespace " . $_ . " { " ;
+        }
+    }
 
-    $$new_contents_ref .= $my_class_contents ;
     # write the class contents and semicolon to ensure any template declarations below are after the semicolon.
-    $$new_contents_ref .= $extracted . ";\n" ;
+    $$new_contents_ref .= "\n" . $my_class_contents . $extracted . ";\n" ;
 
     my $c_ = "$curr_namespace$class_name" ;
     $c_ =~ s/\:/_/g ;
diff --git a/test/SIM_swig_template_scoping/S_overrides.mk b/test/SIM_swig_template_scoping/S_overrides.mk
index 09fe4a9f..e1f6cccd 100644
--- a/test/SIM_swig_template_scoping/S_overrides.mk
+++ b/test/SIM_swig_template_scoping/S_overrides.mk
@@ -1,3 +1,2 @@
-TRICK_CONVERT_SWIG_FLAGS := -s
 TRICK_CFLAGS += -Imodels
 TRICK_CXXFLAGS += -Imodels
diff --git a/test/SIM_swig_template_scoping/models/Classes.hh b/test/SIM_swig_template_scoping/models/Classes.hh
index df1f041a..48ac9338 100644
--- a/test/SIM_swig_template_scoping/models/Classes.hh
+++ b/test/SIM_swig_template_scoping/models/Classes.hh
@@ -1,93 +1,185 @@
-#include <vector>
+// @trick_parse{everything}
 
-namespace a {
-    template<class> class A {
-        private:
-        void operator=(const A&);
+#ifndef Classes_HH
+#define Classes_HH
+
+template <class T>
+class Foo {};
+
+namespace peer {
+    template <class T>
+    class Bar {};
+
+    struct Leek {
+        template <class T>
+        class Eggplant {};
     };
+
+    namespace nested {
+        template <class T>
+        class Broccoli {};
+
+        struct Carrot {
+            template <class T>
+            class Celery {};
+        };
+    }
 }
 
-namespace b {
+namespace prime {
 
-    template<class> class A {};
-    template<class> class B {};
+    template<class T>
+    class Potato {};
 
-    class C {
-        public:
-        std::vector<int> v;
-        a::A<int> a;
-        a::A<int> a2;
-        A<int> a3;
-        A<int> a4;
-        B<int> b;
-        B<int> b2;
-        b::B<int> b3;
-        b::B<int> b4;
-        B<a::A<int> > ba;
-        B<a::A<int> > ba2;
-        b::B<a::A<int> > ba3;
-        b::B<a::A<int> > ba4;
-        B<A<int> > ba5;
-        B<A<int> > ba6;
-
-        // These don't work. Because the type is qualified, convert_swig assumes
-        // it's fully qualified and puts the %template directive in the global
-        // namespace. However, there is no A in the global namespace, so the wrapper
-        // code fails to compile. Bonus points if you can fix this without breaking
-        // something else.
-        //b::B<A<int> > ba7;
-        //b::B<A<int> > ba8;
+    struct Turnip {
+        template <class T>
+        class Radish {};
     };
 
-    // This class is the same as the previous. Seems weird, but it reveals scoping
-    // errors under SWIG 2. The replication is not necessary in SWIG 4, which has
-    // better error detection.
-    class D {
-        public:
-        std::vector<int> v;
-        a::A<int> a;
-        a::A<int> a2;
-        A<int> a3;
-        A<int> a4;
-        B<int> b;
-        B<int> b2;
-        b::B<int> b3;
-        b::B<int> b4;
-        B<a::A<int> > ba;
-        B<a::A<int> > ba2;
-        b::B<a::A<int> > ba3;
-        b::B<a::A<int> > ba4;
-        B<A<int> > ba5;
-        B<A<int> > ba6;
-        //b::B<A<int> > ba7;
-        //b::B<A<int> > ba8;
+    namespace nested {
+        template <class T>
+        class Baz {};
+
+        struct Artichoke {
+            template <class T>
+            class Asparagus {};
+        };
+    }
+
+    struct Onion {
+// ======================= WORKING =============================================
+        /**
+         * We assume a qualified template instantiation is fully qualified
+         * starting from the global namespace, and we put the corresponding
+         * %template directive in the global namespace, which works if our
+         * assumption is correct.
+         */
+        ::Foo<int>                                    fooInt;
+
+          peer::Bar<int>                              barInt;
+        ::peer::Bar<double>                           barDouble;
+
+          peer::Leek::Eggplant<int>                   eggplantInt;
+        ::peer::Leek::Eggplant<double>                eggplantDouble;
+
+          peer::nested::Broccoli<int>                 broccoliInt;
+        ::peer::nested::Broccoli<double>              broccoliDouble;
+
+          peer::nested::Carrot::Celery<int>           celeryInt;
+        ::peer::nested::Carrot::Celery<double>        celeryDouble;
+
+          prime::Potato<int>                          potatoInt;
+        ::prime::Potato<double>                       potatoDouble;
+
+          prime::Turnip::Radish<int>                  radishInt;
+        ::prime::Turnip::Radish<double>               radishDouble;
+
+          prime::nested::Baz<int>                     bazInt;
+        ::prime::nested::Baz<double>                  bazDouble;
+
+          prime::nested::Artichoke::Asparagus<int>    asparagusint;
+        ::prime::nested::Artichoke::Asparagus<double> asparagusDouble;
+
+        /**
+         * We put the %template directive for unqualified template
+         * instantiations in the namespace containing the current class,
+         * which only works if the template is defined in that namespace as
+         * well.
+         */
+        Potato<bool> potatoBool;
+
+// ======================= BROKEN ==============================================
+        /**
+         * Because Foo is declared in the global namespace, its %template
+         * directive must be in that scope as well. However, because the
+         * template instation here is unqualified, we put the %template
+         * directive in the containing namespace, which is an error.
+         *
+         * Error: 'Foo' resolves to '::Foo' and was incorrectly
+         * instantiated in scope 'prime' instead of within scope ''.
+         */
+//        Foo<double> fooDouble;
+
+        /**
+         * Because these template instantiations are qualified, their %template
+         * directives are placed in the global namespace. However, because they
+         * are not _fully_ qualified, the generated SWIG input code is invalid.
+         * For partially-qualified instantiations, the directive should either be:
+         * 1. Declared in the global namespace and qualified with prime::
+         * 2. Declared in the prime namespace
+         *
+         * We don't track enough information to do either.
+         *
+         * Error: Template 'Turnip::Radish' undefined.
+         * Error: Template 'nested::Baz' undefined.
+         * Error: Template 'nested::Artichoke::Asparagus' undefined.
+         */
+//        Turnip::Radish<bool>               radishBool;
+//        nested::Baz<bool>                  bazBool;
+//        nested::Artichoke::Asparagus<bool> asparagusBool;
+
+        template<class T>
+        class InnerOnion {}; // onions have layers!
+
+        /**
+         * All %template directives are placed before the class containing their
+         * corresponding template instantiations. For member templates
+         * (templates declared within the class being processed), this results
+         * in the %template directive referencing the member template before it
+         * has been declared, which is an error.
+         *
+         * Error: Template 'InnerOnion' undefined.
+         * Error: Template 'Onion::InnerOnion' undefined.
+         * Error: Template 'prime::Onion::InnerOnion' undefined.
+         * Error: Template '::prime::Onion::InnerOnion' undefined.
+         */
+//                        InnerOnion<int>    layer1;
+//                 Onion::InnerOnion<double> layer2;
+//          prime::Onion::InnerOnion<bool>   layer2;
+//        ::prime::Onion::InnerOnion<short>  layer4;
     };
+
+    // Same tests as above, but within a nested namespace.
+    namespace nested {
+        class Corn {
+            ::Foo<peer::Leek>                                 fooLeek;
+
+              peer::Bar<Foo<long> >                           barFoo;
+            ::peer::Bar<peer::Leek>                           barLeek;
+
+              peer::Leek::Eggplant<long>                      eggplantLong;
+            ::peer::Leek::Eggplant<peer::Leek>                eggplantLeek;
+
+              peer::nested::Broccoli<long>                    broccoliLong;
+            ::peer::nested::Broccoli<peer::Leek>              broccoliLeek;
+
+              peer::nested::Carrot::Celery<long>              celeryLong;
+            ::peer::nested::Carrot::Celery<peer::Leek>        celeryLeek;
+
+              prime::Potato<long>                             potatoLong;
+            ::prime::Potato<peer::Leek>                       potatoLeek;
+
+              prime::Turnip::Radish<long>                     radishLong;
+            ::prime::Turnip::Radish<peer::Leek>               radishLeek;
+
+              prime::nested::Baz<long>                        bazLong;
+            ::prime::nested::Baz<peer::Leek>                  bazLeek;
+
+              prime::nested::Artichoke::Asparagus<long>       asparagusLong;
+            ::prime::nested::Artichoke::Asparagus<peer::Leek> asparagusLeek;
+
+            // These fail in Onion, but work here because Onion has already been processed.
+              prime::Onion::InnerOnion<long>                  onionLong;
+            ::prime::Onion::InnerOnion<peer::Leek>            onionLeek;
+
+            // These fail for the same reason as in Onion.
+//          Foo<float> fooFloat;
+//          Turnip::Radish<float>               radishFloat;
+//          nested::Baz<float>                  bazFloat;
+//          nested::Artichoke::Asparagus<float> asparagusFloat;
+//          Onion::InnerOnion<float>            innerOnionFloat;
+        };
+    }
 }
 
-class E {
-    public:
-        std::vector<int> v;
-        a::A<int> a;
-        a::A<int> a2;
-        b::B<int> b3;
-        b::B<int> b4;
-        b::B<a::A<int> > ba3;
-        b::B<a::A<int> > ba4;
-};
-
-namespace a {
-    class B {
-        public:
-        std::vector<int> v;
-        a::A<int> a;
-        a::A<int> a2;
-        A<int> a3;
-        A<int> a4;
-        b::B<int> b3;
-        b::B<int> b4;
-        b::B<a::A<int> > ba3;
-        b::B<a::A<int> > ba4;
-        //b::B<A<int> > ba7;
-        //b::B<A<int> > ba8;
-    };
-}
+#endif
diff --git a/test_sims.yml b/test_sims.yml
index 16b89cf5..a6f56dea 100644
--- a/test_sims.yml
+++ b/test_sims.yml
@@ -21,6 +21,8 @@ SIM_parse_s_define:
   path: test/SIM_parse_s_define
 SIM_target_specific_variables:
   path: test/SIM_target_specific_variables
+SIM_swig_template_scoping:
+  path: test/SIM_swig_template_scoping
 SIM_test_abstract:
   path: test/SIM_test_abstract
 SIM_test_inherit: