diff --git a/vis/include/combinations.hpp b/vis/include/combinations.hpp
index 615e9e6..3101601 100644
--- a/vis/include/combinations.hpp
+++ b/vis/include/combinations.hpp
@@ -50,4 +50,4 @@ std::set<V> set_union(const std::set<V> &a, const std::set<V> &b) {
         std::inserter(result, result.end())
         );
     return result;
-}
\ No newline at end of file
+}
diff --git a/vis/include/solver.hpp b/vis/include/solver.hpp
index 9159c0f..c8d823b 100644
--- a/vis/include/solver.hpp
+++ b/vis/include/solver.hpp
@@ -79,10 +79,10 @@ public:
 
     Mesh(const tc::Group &g_, std::vector<int> ctx_, size_t cols);
 
-    static Mesh<N> fill(const tc::Group &g, std::vector<int> ctx);
+    static Mesh<N> fill(const tc::Group &g, const std::vector<int> &ctx);
 
-    template<class SC>
-    static Mesh<N> hull(const tc::Group &g, std::vector<int> ctx, const SC &sub_ctxs);
+//    template<class SC>
+//    static Mesh<N> hull(const tc::Group &g, const std::vector<int> &ctx, const SC &sub_ctxs);
 
     Mesh<N> recontext(std::vector<int> ctx_);
 
@@ -187,7 +187,7 @@ Mesh<N>::Mesh(const tc::Group &g_, std::vector<int> ctx_, size_t cols)
 }
 
 template<unsigned N>
-Mesh<N> Mesh<N>::fill(const tc::Group &g, std::vector<int> ctx) {
+Mesh<N> Mesh<N>::fill(const tc::Group &g, const std::vector<int> &ctx) {
     if (ctx.size() + 1 != N)
         throw std::logic_error("ctx size must be one less than N");
 
@@ -212,22 +212,45 @@ Mesh<N> Mesh<N>::fill(const tc::Group &g, std::vector<int> ctx) {
 }
 
 template<>
-Mesh<1> Mesh<1>::fill(const tc::Group &g, std::vector<int> ctx) {
+Mesh<1> Mesh<1>::fill(const tc::Group &g, const std::vector<int> &ctx) {
     if (not ctx.empty())
         throw std::logic_error("ctx must be empty for a trivial Mesh.");
 
     return Mesh<1>(g, ctx, 1);
 }
 
-template<unsigned N>
-template<class SC>
-Mesh<N> Mesh<N>::hull(const tc::Group &g, const std::vector<int> ctx, const SC &sub_ctxs) {
+template<unsigned N, class C, class SC>
+Mesh<N> fill_each_tile_merge(const tc::Group &g, const C &ctx, const SC &sub_ctxs) {
     std::vector<Mesh<N>> parts;
 
     for (const auto &sub_ctx : sub_ctxs) {
-        auto face = Mesh<N>::fill(g, sub_ctx).each_tile(ctx);
-        parts.insert(parts.end(), face.begin(), face.end());
+        auto root = Mesh<N>::fill(g, sub_ctx);
+        auto faces = root.each_tile(ctx);
+        parts.insert(parts.end(), faces.begin(), faces.end());
     }
 
     return merge(parts);
 }
+
+template<unsigned N, class SC>
+Mesh<N> fill_each_tile_merge(const tc::Group &g, const SC &sub_ctxs) {
+    return fill_each_tile_merge<N>(g, generators(g), sub_ctxs);
+}
+
+template<unsigned N, class C, class SC>
+Mesh<N> fill_each_recontext_merge(const tc::Group &g, const C &ctx, const SC &sub_ctxs) {
+    std::vector<Mesh<N>> parts;
+
+    for (const auto &sub_ctx : sub_ctxs) {
+        auto root = Mesh<N>::fill(g, sub_ctx);
+        auto face = root.recontext(ctx);
+        parts.insert(parts.end(), face);
+    }
+
+    return merge(parts);
+}
+
+template<unsigned N, class SC>
+Mesh<N> fill_each_recontext_merge(const tc::Group &g, const SC &sub_ctxs) {
+    return fill_each_recontext_merge<N>(g, generators(g), sub_ctxs);
+}
diff --git a/vis/src/main.cpp b/vis/src/main.cpp
index a4c30de..d359a89 100644
--- a/vis/src/main.cpp
+++ b/vis/src/main.cpp
@@ -50,14 +50,14 @@ public:
         4, 5) {
         using namespace nanogui;
 
-        Window *window = new Window(this, "Sample Window");
+        auto *window = new Window(this, "Sample Window");
         window->setPosition(Vector2i(15, 15));
         window->setFixedWidth(250);
         window->setLayout(new BoxLayout(Orientation::Vertical));
 
-        auto pause = new ToolButton(window, ENTYPO_ICON_CONTROLLER_PAUS);
-        pause->setFlags(Button::ToggleButton);
-        pause->setChangeCallback([&](bool value) { this->paused = value; });
+//        auto pause = new ToolButton(window, ENTYPO_ICON_CONTROLLER_PAUS);
+//        pause->setFlags(Button::ToggleButton);
+//        pause->setChangeCallback([&](bool value) { this->paused = value; });
 
         performLayout();
 
@@ -73,31 +73,13 @@ public:
                     {0, 1, 2},
                 }
             );
-            auto mesh = Mesh<4>::hull(group, ctx, selected_ctxs);
+            auto mesh = fill_each_tile_merge<4>(group, selected_ctxs);
 
             auto &slice = slices.emplace_back(group);
             slice.setMesh(mesh);
             slice.root << .80, .02, .02, .02, .02;
         }
 
-        {
-            std::vector<int> symbol = {3, 4, 3, 2};
-            auto group = tc::schlafli(symbol);
-            auto ctx = generators(group);
-
-            auto selected_ctxs = set_union(
-                combinations(std::vector<int>{0, 2, 3, 4}, 3),
-                combinations(std::vector<int>{1, 2, 3, 4}, 3)
-            );
-
-            auto mesh = Mesh<4>::hull(group, ctx, selected_ctxs);
-
-            auto &slice = slices.emplace_back(group);
-            slice.setMesh(mesh);
-            slice.root << .80, .02, .02, .03, .04;
-            slice.color << 0.9, 0.1, 0.1;
-        }
-        
         ren = std::make_unique<SliceRenderer<4>>();
 
         ubo = std::make_unique<cgl::Buffer<Matrices>>();
@@ -134,7 +116,7 @@ public:
     }
 };
 
-int main(int argc, char ** argv) {
+int main(int argc, char **argv) {
     try {
         nanogui::init();
 
@@ -153,4 +135,4 @@ int main(int argc, char ** argv) {
     }
 
     return 0;
-}
\ No newline at end of file
+}