125 rendering is flipped ud

examples/video_recording.py

@@ -15,7 +15,7 @@ def main():
     }
 
     env = gym.make(
-        "f1tenth_gym:f1tenth-v0,
+        "f1tenth_gym:f1tenth-v0",
         config={
             "map": "Spielberg",
             "num_agents": 1,

f1tenth_gym/envs/rendering/objects.py

@@ -3,6 +3,7 @@
 import numpy as np
 import pygame
 
+from .utils import to_pygame
 from ..collision_models import get_vertices
 from . import RenderSpec
 
@@ -217,6 +218,8 @@ def render(self, display: pygame.Surface):
             self.resolution * self.ppu
         )
 
+        vertices = to_pygame(vertices, height=display.get_height())
+
         self.rect = pygame.draw.polygon(display, self.color, vertices)
 
         pygame.draw.lines(display, (0, 0, 0), True, vertices, self.car_tickness)

f1tenth_gym/envs/rendering/rendering_pygame.py

@@ -13,6 +13,7 @@
     Car,
     TextObject,
 )
+from .utils import to_pygame
 from ..track import Track
 from .renderer import EnvRenderer, RenderSpec
 
@@ -104,8 +105,9 @@ def __init__(
             window_shape=(width, height), position="top_center"
         )
 
-        # load map image
+        # load map image (flip it vertically to match the pygame coordinate system)
         original_img = track.occupancy_map
+        original_img = np.flipud(original_img)
 
         self.map_renderers = {
             "map": Map(map_img=original_img, zoom_level=0.4),
@@ -212,6 +214,7 @@ def render(self) -> Optional[np.ndarray]:
                 ego_x, ego_y = self.cars[self.agent_to_follow].pose[:2]
                 cx = (ego_x - origin[0]) / resolution
                 cy = (ego_y - origin[1]) / resolution
+                cx, cy = to_pygame(np.array([cx, cy]), height=self.map_canvas.get_height())
             else:
                 cx = self.map_canvas.get_width() / 2
                 cy = self.map_canvas.get_height() / 2
@@ -330,6 +333,7 @@ def render_points(
         ppu = self.ppus[self.active_map_renderer]
         resolution = self.map_resolution * ppu
         points = ((points - origin[:2]) / resolution).astype(int)
+        points = to_pygame(points, height=self.map_canvas.get_height())
         size = math.ceil(size / ppu)
 
         for point in points:
@@ -357,6 +361,7 @@ def render_lines(
         ppu = self.ppus[self.active_map_renderer]
         resolution = self.map_resolution * ppu
         points = ((points - origin[:2]) / resolution).astype(int)
+        points = to_pygame(points, height=self.map_canvas.get_height())
         size = math.ceil(size / ppu)
 
         pygame.draw.lines(
@@ -385,6 +390,7 @@ def render_closed_lines(
         ppu = self.ppus[self.active_map_renderer]
         resolution = self.map_resolution * ppu
         points = ((points - origin[:2]) / resolution).astype(int)
+        points = to_pygame(points, height=self.map_canvas.get_height())
         size = math.ceil(size / ppu)
 
         pygame.draw.lines(

f1tenth_gym/envs/rendering/utils.py

@@ -0,0 +1,8 @@
+import numpy as np
+
+
+def to_pygame(coords: np.ndarray, height: int) -> np.ndarray:
+    """Convert coordinates into pygame coordinates (lower-left => top left)."""
+    if coords.ndim == 1:
+        return np.array([coords[0], height - coords[1]])
+    return np.array([coords[:, 0], height - coords[:, 1]]).T