diff --git a/examples/viewer.py b/examples/viewer.py
index c479482554..21241ace67 100644
--- a/examples/viewer.py
+++ b/examples/viewer.py
@@ -53,24 +53,25 @@ def __init__(self, sim_settings: Dict[str, Any]) -> None:
         )
 
         # Compute environment camera resolution based on the number of environments to render in the window.
-        surface_size: tuple(int, int) = (
+        window_size: mn.Vector2 = (
             self.sim_settings["window_width"],
             self.sim_settings["window_height"],
         )
-        grid_size: tuple(int, int) = ReplayRenderer.environment_grid_size(self.num_env)
-        camera_resolution: tuple(int, int) = (
-            surface_size[0] / grid_size[0],
-            surface_size[1] / grid_size[1],
-        )
-        self.sim_settings["width"] = camera_resolution[0]
-        self.sim_settings["height"] = camera_resolution[1]
 
         configuration = self.Configuration()
         configuration.title = "Habitat Sim Interactive Viewer"
-        configuration.size = surface_size
+        configuration.size = window_size
         Application.__init__(self, configuration)
         self.fps: float = 60.0
 
+        # Compute environment camera resolution based on the number of environments to render in the window.
+        grid_size: mn.Vector2i = ReplayRenderer.environment_grid_size(self.num_env)
+        camera_resolution: mn.Vector2 = mn.Vector2(self.framebuffer_size) / mn.Vector2(
+            grid_size
+        )
+        self.sim_settings["width"] = camera_resolution[0]
+        self.sim_settings["height"] = camera_resolution[1]
+
         # draw Bullet debug line visualizations (e.g. collision meshes)
         self.debug_bullet_draw = False
         # draw active contact point debug line visualizations
@@ -138,11 +139,12 @@ def __init__(self, sim_settings: Dict[str, Any]) -> None:
         # text object transform in window space is Projection matrix times Translation Matrix
         # put text in top left of window
         self.window_text_transform = mn.Matrix3.projection(
-            mn.Vector2(surface_size)
+            self.framebuffer_size
         ) @ mn.Matrix3.translation(
-            mn.Vector2(
-                surface_size[0] * -HabitatSimInteractiveViewer.TEXT_DELTA_FROM_CENTER,
-                surface_size[1] * HabitatSimInteractiveViewer.TEXT_DELTA_FROM_CENTER,
+            mn.Vector2(self.framebuffer_size)
+            * mn.Vector2(
+                -HabitatSimInteractiveViewer.TEXT_DELTA_FROM_CENTER,
+                HabitatSimInteractiveViewer.TEXT_DELTA_FROM_CENTER,
             )
         )
         self.shader = shaders.VectorGL2D()