diff --git a/metadrive/engine/core/engine_core.py b/metadrive/engine/core/engine_core.py
index 2b6b72505..1a4ebd47f 100644
--- a/metadrive/engine/core/engine_core.py
+++ b/metadrive/engine/core/engine_core.py
@@ -83,8 +83,6 @@ class EngineCore(ShowBase.ShowBase):
     DEBUG = False
     global_config = None  # global config can exist before engine initialization
     loadPrcFileData("", "window-title {}".format(EDITION))
-    loadPrcFileData("", "framebuffer-multisample 1")
-    loadPrcFileData("", "multisamples 8")
     loadPrcFileData("", "bullet-filter-algorithm groups-mask")
     loadPrcFileData("", "audio-library-name null")
     loadPrcFileData("", "model-cache-compressed-textures 1")
@@ -98,15 +96,11 @@ class EngineCore(ShowBase.ShowBase):
     # loadPrcFileData("", "allow-incomplete-render #t")
     # loadPrcFileData("", "# even-animation #t")
 
-    # loadPrcFileData("", " framebuffer-srgb truein")
     # loadPrcFileData("", "geom-cache-size 50000")
 
     # v-sync, it seems useless
     # loadPrcFileData("", "sync-video 1")
 
-    # for debug use
-    # loadPrcFileData("", "gl-version 3 2")
-
     if is_mac():
       # latest macOS supported openGL version
       loadPrcFileData("", "gl-version 4 1")
@@ -169,9 +163,6 @@ def __init__(self, global_config):
                     # Disable useless camera capturing in none mode
                     self.global_config["show_interface"] = False
 
-        if is_mac() and (self.mode == RENDER_MODE_OFFSCREEN):  # Mac don't support offscreen rendering
-            self.mode = RENDER_MODE_ONSCREEN
-
         loadPrcFileData("", "win-size {} {}".format(*self.global_config["window_size"]))
 
         if self.use_render_pipeline:
diff --git a/metadrive/engine/core/sky_box.py b/metadrive/engine/core/sky_box.py
index 1155e7e62..519dc8660 100644
--- a/metadrive/engine/core/sky_box.py
+++ b/metadrive/engine/core/sky_box.py
@@ -40,12 +40,8 @@ def __init__(self, pure_background: bool = False, use_anisotropic_filtering: boo
                 AssetLoader.file_path("../shaders", "skybox_gles.frag.glsl")
             )
         else:
-            if is_mac():
-                vert_file = "skybox_mac.vert.glsl"
-                frag_file = "skybox_mac.frag.glsl"
-            else:
-                vert_file = "skybox.vert.glsl"
-                frag_file = "skybox.frag.glsl"
+            vert_file = "skybox.vert.glsl"
+            frag_file = "skybox.frag.glsl"
             skybox_shader = Shader.load(
                 Shader.SL_GLSL, AssetLoader.file_path("../shaders", vert_file),
                 AssetLoader.file_path("../shaders", frag_file)
diff --git a/metadrive/engine/core/terrain.py b/metadrive/engine/core/terrain.py
index c0ec519cd..b5cd89d03 100644
--- a/metadrive/engine/core/terrain.py
+++ b/metadrive/engine/core/terrain.py
@@ -423,7 +423,7 @@ def _load_mesh_terrain_textures(self, engine, anisotropic_degree=16, filter_type
             tex.set_wrap_v(v_wrap)
             tex.setMinfilter(filter_type)
             tex.setMagfilter(filter_type)
-            tex.setAnisotropicDegree(anisotropic_degree)
+            tex.setAnisotropicDegree(1)
 
         # # sidewalk
         # self.side_tex = self.loader.loadTexture(AssetLoader.file_path("textures", "sidewalk", "color.png"))
@@ -450,7 +450,7 @@ def _load_mesh_terrain_textures(self, engine, anisotropic_degree=16, filter_type
             tex.set_wrap_v(v_wrap)
             tex.setMinfilter(filter_type)
             tex.setMagfilter(filter_type)
-            tex.setAnisotropicDegree(anisotropic_degree)
+            tex.setAnisotropicDegree(1)
         # self.road_texture_displacement = self.loader.loadTexture(AssetLoader.file_path("textures", "sci", "normal.jpg"))
         # self.road_texture.setMinfilter(minfilter)
         # self.road_texture.setAnisotropicDegree(anisotropic_degree)
diff --git a/metadrive/shaders/terrain.frag.glsl b/metadrive/shaders/terrain.frag.glsl
index c7189705c..4f0d03f4c 100644
--- a/metadrive/shaders/terrain.frag.glsl
+++ b/metadrive/shaders/terrain.frag.glsl
@@ -201,7 +201,7 @@ void main() {
         float radius = 0.001; // Sample radius
         for(int x = -1; x <= 1; x++) {
             for(int y = -1; y <= 1; y++) {
-                float depth_sample = texture2D(PSSMShadowAtlas, projected_coord.xy + vec2(x, y) * radius).r;
+                float depth_sample = texture(PSSMShadowAtlas, projected_coord.xy + vec2(x, y) * radius).r;
                 shadow_factor += step(ref_depth, depth_sample);
         }
         }
@@ -233,4 +233,4 @@ void main() {
 //     shading = vec3(0, 1, 1);
 //   }
   color = vec4(shading, 1.0);
-}
\ No newline at end of file
+}