Update nodes_sampler.py

nodes_sampler.py

@@ -1351,12 +1351,15 @@ class WanVideoSampler:
                     z = z * c_in
                     timestep = c_noise
 
-                self.noise_front_pad_num = image_cond_input.shape[1] - z.shape[1]
+                if image_cond is not None:
-                if self.noise_front_pad_num > 0:
+                    self.noise_front_pad_num = image_cond_input.shape[1] - z.shape[1]
-                    pad = torch.zeros((z.shape[0], self.noise_front_pad_num, z.shape[2], z.shape[3]), dtype=z.dtype, device=z.device)
+                    if self.noise_front_pad_num > 0:
-                    z = torch.concat([pad, z], dim=1)
+                        pad = torch.zeros((z.shape[0], self.noise_front_pad_num, z.shape[2], z.shape[3]), dtype=z.dtype, device=z.device)
-                    nonlocal seq_len
+                        z = torch.concat([pad, z], dim=1)
-                    seq_len = math.ceil((z.shape[2] * z.shape[3]) / 4 * z.shape[1])
+                        nonlocal seq_len
+                        seq_len = math.ceil((z.shape[2] * z.shape[3]) / 4 * z.shape[1])
+                else:
+                    self.noise_front_pad_num = 0
 
                 base_params = {
                     'x': [z], # latent