diff --git a/genesis/utils/mjcf.py b/genesis/utils/mjcf.py
index acf13d7..2326e0b 100644
--- a/genesis/utils/mjcf.py
+++ b/genesis/utils/mjcf.py
@@ -1,4 +1,5 @@
 import os
+import xml.etree.ElementTree as ET
 
 import mujoco
 import numpy as np
@@ -12,8 +13,6 @@
 from . import mesh as mu
 from .misc import get_assets_dir
 
-import xml.etree.ElementTree as ET
-
 
 def extract_compiler_attributes(xml_path):
     # Parse the XML file
@@ -302,16 +301,11 @@ def parse_geom(mj, i_g, scale, convexify, surface, xml_path):
                 uv_coordinates = tmesh.vertices[:, :2].copy()
                 uv_coordinates -= uv_coordinates.min(axis=0)
                 uv_coordinates /= uv_coordinates.max(axis=0)
-                image = Image.open(os.path.join(assets_dir, tex_path))
+                image = Image.open(os.path.join(assets_dir, tex_path)).convert("RGBA")
                 image_array = np.array(image)
-                if image_array.ndim == 2:  # convert gray image to RGBA
-                    rgba = np.zeros((image_array.shape[0], image_array.shape[1], 4), dtype=np.uint8)
-                    rgba[:, :, :3] = image_array[:, :, None]
-                    rgba[:, :, 3] = 255
-                    image_array = rgba
                 tex_repeat = mj.mat_texrepeat[mat_id].astype(int)
                 image_array = np.tile(image_array, (tex_repeat[0], tex_repeat[1], 1))
-                visual = TextureVisuals(uv=uv_coordinates, image=Image.fromarray(image_array))
+                visual = TextureVisuals(uv=uv_coordinates, image=Image.fromarray(image_array, mode="RGBA"))
                 tmesh.visual = visual
 
     elif mj_type == mujoco.mjtGeom.mjGEOM_MESH:
@@ -326,6 +320,10 @@ def parse_geom(mj, i_g, scale, convexify, surface, xml_path):
 
         if tex_start >= 0:
             tex_end = mj.mesh_texcoordadr[i + 1] if not last else mj.mesh_texcoord.shape[0]
+            if tex_end == -1:
+                tex_end = tex_start + (vert_end - vert_start)
+            assert tex_end - tex_start == vert_end - vert_start
+
             mat_id = mj.geom_matid[i_g]
             tex_id = next((x for x in mj.mat_texid[mat_id] if x != -1), None)
             if not tex_id is None:
@@ -336,7 +334,12 @@ def parse_geom(mj, i_g, scale, convexify, surface, xml_path):
                 # TODO: check if we can parse <compiler> tag with mj model
                 texturedir = extract_compiler_attributes(xml_path)["texturedir"]
                 assets_dir = os.path.join(get_assets_dir(), os.path.join(os.path.dirname(xml_path), texturedir))
-                visual = TextureVisuals(uv=uv, image=Image.open(os.path.join(assets_dir, tex_path)))
+
+                image = Image.open(os.path.join(assets_dir, tex_path)).convert("RGBA")
+                image_array = np.array(image)
+                tex_repeat = mj.mat_texrepeat[mat_id].astype(int)
+                image_array = np.tile(image_array, (tex_repeat[0], tex_repeat[1], 1))
+                visual = TextureVisuals(uv=uv, image=Image.fromarray(image_array, mode="RGBA"))
 
         tmesh = trimesh.Trimesh(
             vertices=mj.mesh_vert[vert_start:vert_end],