diff --git a/gsplat/cuda/csrc/forward.cu b/gsplat/cuda/csrc/forward.cu
index da537b4ce..3751a75ff 100644
--- a/gsplat/cuda/csrc/forward.cu
+++ b/gsplat/cuda/csrc/forward.cu
@@ -146,12 +146,11 @@ __global__ void get_tile_bin_edges(
         return;
     // save the indices where the tile_id changes
     int32_t cur_tile_idx = (int32_t)(isect_ids_sorted[idx] >> 32);
-    if (idx == 0) {
-        tile_bins[cur_tile_idx].x = 0;
-        return;
-    }
-    if (idx == num_intersects - 1) {
-        tile_bins[cur_tile_idx].y = num_intersects;
+    if (idx == 0 || idx == num_intersects - 1) {
+        if (idx == 0)
+            tile_bins[cur_tile_idx].x = 0;
+        if (idx == num_intersects - 1)
+            tile_bins[cur_tile_idx].y = num_intersects;
         return;
     }
     int32_t prev_tile_idx = (int32_t)(isect_ids_sorted[idx - 1] >> 32);
diff --git a/gsplat/cuda/csrc/helpers.cuh b/gsplat/cuda/csrc/helpers.cuh
index dd5be7e7b..423733395 100644
--- a/gsplat/cuda/csrc/helpers.cuh
+++ b/gsplat/cuda/csrc/helpers.cuh
@@ -5,7 +5,7 @@
 #include <iostream>
 
 inline __device__ float ndc2pix(const float x, const float W, const float cx) {
-    return 0.5f * W * x + 0.5f + cx;
+    return 0.5f * W * x + cx - 0.5;
 }
 
 inline __device__ void get_bbox(