diff --git a/samples/sample_cloth.cpp b/samples/sample_cloth.cpp
index 4f6eec4f12..13ea7a743f 100644
--- a/samples/sample_cloth.cpp
+++ b/samples/sample_cloth.cpp
@@ -72,6 +72,8 @@ static void printUsage(char* name) {
             "Options:\n"
             "   --help, -h\n"
             "       Prints this message\n\n"
+            "   --api, -a\n"
+            "       Specify the backend API: opengl (default), vulkan, or metal\n\n"
             "   --ibl=<path to cmgen IBL>, -i <path>\n"
             "       Applies an IBL generated by cmgen's deploy option\n\n"
             "   --split-view, -v\n"
@@ -87,9 +89,10 @@ static void printUsage(char* name) {
 }
 
 static int handleCommandLineArgments(int argc, char* argv[], Config* config) {
-    static constexpr const char* OPTSTR = "hi:vs:";
+    static constexpr const char* OPTSTR = "ha:i:vs:";
     static const struct option OPTIONS[] = {
             { "help",           no_argument,       0, 'h' },
+            { "api",            required_argument, 0, 'a' },
             { "ibl",            required_argument, 0, 'i' },
             { "split-view",     no_argument,       0, 'v' },
             { "scale",          required_argument, 0, 's' },
@@ -104,6 +107,17 @@ static int handleCommandLineArgments(int argc, char* argv[], Config* config) {
             case 'h':
                 printUsage(argv[0]);
                 exit(0);
+            case 'a':
+                if (arg == "opengl") {
+                    config->backend = Engine::Backend::OPENGL;
+                } else if (arg == "vulkan") {
+                    config->backend = Engine::Backend::VULKAN;
+                } else if (arg == "metal") {
+                    config->backend = Engine::Backend::METAL;
+                } else {
+                    std::cerr << "Unrecognized backend. Must be 'opengl'|'vulkan'|'metal'." << std::endl;
+                }
+                break;
             case 'i':
                 config->iblDirectory = arg;
                 break;
@@ -188,6 +202,10 @@ static void setup(Engine* engine, View* view, Scene* scene) {
     MaterialBuilder::init();
     MaterialBuilder builder = MaterialBuilder()
             .name("DefaultMaterial")
+            .targetApi(MaterialBuilder::TargetApi::ALL)
+#ifndef NDEBUG
+            .optimization(MaterialBuilderBase::Optimization::NONE)
+#endif
             .require(VertexAttribute::UV0)
             .parameter(MaterialBuilder::SamplerType::SAMPLER_2D, "normalMap")
             .parameter(MaterialBuilder::SamplerType::SAMPLER_2D, "basecolorMap")
diff --git a/samples/sample_full_pbr.cpp b/samples/sample_full_pbr.cpp
index 48859e7a06..2e12c5e1cf 100644
--- a/samples/sample_full_pbr.cpp
+++ b/samples/sample_full_pbr.cpp
@@ -101,6 +101,8 @@ static void printUsage(char* name) {
             "Options:\n"
             "   --help, -h\n"
             "       Prints this message\n\n"
+            "   --api, -a\n"
+            "       Specify the backend API: opengl (default), vulkan, or metal\n\n"
             "   --ibl=<path to cmgen IBL>, -i <path>\n"
             "       Applies an IBL generated by cmgen's deploy option\n\n"
             "   --split-view, -v\n"
@@ -120,7 +122,7 @@ static void printUsage(char* name) {
             "\n"
             "   --clear-coat, -c\n"
             "       Add a clear coat layer to the material\n\n"
-            "   --anisotropy, -a\n"
+            "   --anisotropy, -A\n"
             "       Enable anisotropy on the material\n\n"
     );
     const std::string from("SAMPLE_PBR");
@@ -131,15 +133,16 @@ static void printUsage(char* name) {
 }
 
 static int handleCommandLineArgments(int argc, char* argv[], Config* config) {
-    static constexpr const char* OPTSTR = "hi:vs:m:ca";
+    static constexpr const char* OPTSTR = "ha:i:vs:m:cA";
     static const struct option OPTIONS[] = {
             { "help",           no_argument,       nullptr, 'h' },
+            { "api",            required_argument, nullptr, 'a' },
             { "ibl",            required_argument, nullptr, 'i' },
             { "split-view",     no_argument,       nullptr, 'v' },
             { "scale",          required_argument, nullptr, 's' },
             { "material",       required_argument, nullptr, 'm' },
             { "clear-coat",     no_argument,       nullptr, 'c' },
-            { "anisotropy",     no_argument,       nullptr, 'a' },
+            { "anisotropy",     no_argument,       nullptr, 'A' },
             { 0, 0, 0, 0 }  // termination of the option list
     };
     int opt;
@@ -151,6 +154,17 @@ static int handleCommandLineArgments(int argc, char* argv[], Config* config) {
             case 'h':
                 printUsage(argv[0]);
                 exit(0);
+            case 'a':
+                if (arg == "opengl") {
+                    config->backend = Engine::Backend::OPENGL;
+                } else if (arg == "vulkan") {
+                    config->backend = Engine::Backend::VULKAN;
+                } else if (arg == "metal") {
+                    config->backend = Engine::Backend::METAL;
+                } else {
+                    std::cerr << "Unrecognized backend. Must be 'opengl'|'vulkan'|'metal'." << std::endl;
+                }
+                break;
             case 'i':
                 config->iblDirectory = arg;
                 break;
@@ -172,7 +186,7 @@ static int handleCommandLineArgments(int argc, char* argv[], Config* config) {
             case 'c':
                 g_pbrConfig.clearCoat = true;
                 break;
-            case 'a':
+            case 'A':
                 g_pbrConfig.anisotropy = true;
                 break;
         }
@@ -360,6 +374,10 @@ static void setup(Engine* engine, View* view, Scene* scene) {
     MaterialBuilder::init();
     MaterialBuilder builder = MaterialBuilder()
             .name("DefaultMaterial")
+            .targetApi(MaterialBuilder::TargetApi::ALL)
+#ifndef NDEBUG
+            .optimization(MaterialBuilderBase::Optimization::NONE)
+#endif
             .material(shader.c_str())
             .multiBounceAmbientOcclusion(true)
             .specularAmbientOcclusion(MaterialBuilder::SpecularAmbientOcclusion::BENT_NORMALS)
diff --git a/samples/sample_normal_map.cpp b/samples/sample_normal_map.cpp
index 9a95d4d2ff..71fcfe3fe5 100644
--- a/samples/sample_normal_map.cpp
+++ b/samples/sample_normal_map.cpp
@@ -78,6 +78,8 @@ static void printUsage(char* name) {
             "Options:\n"
             "   --help, -h\n"
             "       Prints this message\n\n"
+            "   --api, -a\n"
+            "       Specify the backend API: opengl (default), vulkan, or metal\n\n"
             "   --ibl=<path to cmgen IBL>, -i <path>\n"
             "       Applies an IBL generated by cmgen's deploy option\n\n"
             "   --split-view, -v\n"
@@ -99,9 +101,10 @@ static void printUsage(char* name) {
 }
 
 static int handleCommandLineArgments(int argc, char* argv[], Config* config) {
-    static constexpr const char* OPTSTR = "hi:vs:n:a:c:b:";
+    static constexpr const char* OPTSTR = "ha:i:vs:n:a:c:b:";
     static const struct option OPTIONS[] = {
             { "help",                   no_argument,       nullptr, 'h' },
+            { "api",                    required_argument, nullptr, 'a' },
             { "ibl",                    required_argument, nullptr, 'i' },
             { "split-view",             no_argument,       nullptr, 'v' },
             { "scale",                  required_argument, nullptr, 's' },
@@ -119,6 +122,17 @@ static int handleCommandLineArgments(int argc, char* argv[], Config* config) {
             case 'h':
                 printUsage(argv[0]);
                 exit(0);
+            case 'a':
+                if (arg == "opengl") {
+                    config->backend = Engine::Backend::OPENGL;
+                } else if (arg == "vulkan") {
+                    config->backend = Engine::Backend::VULKAN;
+                } else if (arg == "metal") {
+                    config->backend = Engine::Backend::METAL;
+                } else {
+                    std::cerr << "Unrecognized backend. Must be 'opengl'|'vulkan'|'metal'." << std::endl;
+                }
+                break;
             case 'i':
                 config->iblDirectory = arg;
                 break;
@@ -277,6 +291,10 @@ static void setup(Engine* engine, View*, Scene* scene) {
     MaterialBuilder::init();
     MaterialBuilder builder = MaterialBuilder()
             .name("DefaultMaterial")
+            .targetApi(MaterialBuilder::TargetApi::ALL)
+#ifndef NDEBUG
+            .optimization(MaterialBuilderBase::Optimization::NONE)
+#endif
             .material(shader.c_str())
             .specularAntiAliasing(true)
             .shading(Shading::LIT);