Allow loading custom models and improve path logic

sgm/inference/api.py

@@ -1,6 +1,7 @@
 from dataclasses import dataclass, asdict
 from enum import Enum
 from omegaconf import OmegaConf
+import os
 import pathlib
 from sgm.inference.helpers import (
     do_sample,
@@ -158,18 +159,33 @@ class SamplingSpec:
 class SamplingPipeline:
     def __init__(
         self,
-        model_id: ModelArchitecture,
-        model_path="checkpoints",
-        config_path="configs/inference",
+        model_id: Optional[ModelArchitecture] = None,
+        model_spec: Optional[SamplingSpec] = None,
+        model_path=None,
+        config_path=None,
         device="cuda",
         use_fp16=True,
-    ) -> None:
-        if model_id not in model_specs:
-            raise ValueError(f"Model {model_id} not supported")
+    ) -> None:        
         self.model_id = model_id
-        self.specs = model_specs[self.model_id]
-        self.config = str(pathlib.Path(config_path, self.specs.config))
-        self.ckpt = str(pathlib.Path(model_path, self.specs.ckpt))
+        if model_spec is not None:
+            self.specs = model_spec
+        elif model_id is not None:
+            if model_id not in model_specs:
+                raise ValueError(f"Model {model_id} not supported")
+            self.specs = model_specs[model_id]
+        else:
+            raise ValueError("Either model_id or model_spec should be provided")
+
+        if model_path is None:
+            model_path = pathlib.Path(__file__).parent.parent.resolve() / "checkpoints"
+        if config_path is None:
+            config_path = pathlib.Path(__file__).parent.parent.resolve() / "configs/inference"                
+        self.config = str(config_path / self.specs.config)
+        self.ckpt = str(model_path / self.specs.ckpt)
+        if not os.path.exists(self.config):
+            raise ValueError(f"Config {self.config} not found, check model spec or config_path")        
+        if not os.path.exists(self.ckpt):
+            raise ValueError(f"Checkpoint {self.ckpt} not found, check model spec or config_path")
         self.device = device
         self.model = self._load_model(device=device, use_fp16=use_fp16)