import torch import inspect import numpy as np from typing import Callable, List, Optional, Union from transformers import CLIPTextModel, CLIPTokenizer from diffusers import AutoencoderKL, DiffusionPipeline from diffusers.utils import ( deprecate, is_accelerate_available, is_accelerate_version, logging, ) from diffusers.configuration_utils import FrozenDict from diffusers.schedulers import DDIMScheduler from diffusers.utils.torch_utils import randn_tensor from .models import MultiViewUNetModel logger = logging.get_logger(__name__) # pylint: disable=invalid-name def create_camera_to_world_matrix(elevation, azimuth): elevation = np.radians(elevation) azimuth = np.radians(azimuth) # Convert elevation and azimuth angles to Cartesian coordinates on a unit sphere x = np.cos(elevation) * np.sin(azimuth) y = np.sin(elevation) z = np.cos(elevation) * np.cos(azimuth) # Calculate camera position, target, and up vectors camera_pos = np.array([x, y, z]) target = np.array([0, 0, 0]) up = np.array([0, 1, 0]) # Construct view matrix forward = target - camera_pos forward /= np.linalg.norm(forward) right = np.cross(forward, up) right /= np.linalg.norm(right) new_up = np.cross(right, forward) new_up /= np.linalg.norm(new_up) cam2world = np.eye(4) cam2world[:3, :3] = np.array([right, new_up, -forward]).T cam2world[:3, 3] = camera_pos return cam2world def convert_opengl_to_blender(camera_matrix): if isinstance(camera_matrix, np.ndarray): # Construct transformation matrix to convert from OpenGL space to Blender space flip_yz = np.array([[1, 0, 0, 0], [0, 0, -1, 0], [0, 1, 0, 0], [0, 0, 0, 1]]) camera_matrix_blender = np.dot(flip_yz, camera_matrix) else: # Construct transformation matrix to convert from OpenGL space to Blender space flip_yz = torch.tensor( [[1, 0, 0, 0], [0, 0, -1, 0], [0, 1, 0, 0], [0, 0, 0, 1]] ) if camera_matrix.ndim == 3: flip_yz = flip_yz.unsqueeze(0) camera_matrix_blender = torch.matmul(flip_yz.to(camera_matrix), camera_matrix) return camera_matrix_blender def get_camera( num_frames, elevation=15, azimuth_start=0, azimuth_span=360, blender_coord=True ): angle_gap = azimuth_span / num_frames cameras = [] for azimuth in np.arange(azimuth_start, azimuth_span + azimuth_start, angle_gap): camera_matrix = create_camera_to_world_matrix(elevation, azimuth) if blender_coord: camera_matrix = convert_opengl_to_blender(camera_matrix) cameras.append(camera_matrix.flatten()) return torch.tensor(np.stack(cameras, 0)).float() class MVDreamPipeline(DiffusionPipeline): def __init__( self, vae: AutoencoderKL, unet: MultiViewUNetModel, tokenizer: CLIPTokenizer, text_encoder: CLIPTextModel, scheduler: DDIMScheduler, requires_safety_checker: bool = False, ): super().__init__() if hasattr(scheduler.config, "steps_offset") and scheduler.config.steps_offset != 1: # type: ignore deprecation_message = ( f"The configuration file of this scheduler: {scheduler} is outdated. `steps_offset`" f" should be set to 1 instead of {scheduler.config.steps_offset}. Please make sure " # type: ignore "to update the config accordingly as leaving `steps_offset` might led to incorrect results" " in future versions. If you have downloaded this checkpoint from the Hugging Face Hub," " it would be very nice if you could open a Pull request for the `scheduler/scheduler_config.json`" " file" ) deprecate( "steps_offset!=1", "1.0.0", deprecation_message, standard_warn=False ) new_config = dict(scheduler.config) new_config["steps_offset"] = 1 scheduler._internal_dict = FrozenDict(new_config) if hasattr(scheduler.config, "clip_sample") and scheduler.config.clip_sample is True: # type: ignore deprecation_message = ( f"The configuration file of this scheduler: {scheduler} has not set the configuration `clip_sample`." " `clip_sample` should be set to False in the configuration file. Please make sure to update the" " config accordingly as not setting `clip_sample` in the config might lead to incorrect results in" " future versions. If you have downloaded this checkpoint from the Hugging Face Hub, it would be very" " nice if you could open a Pull request for the `scheduler/scheduler_config.json` file" ) deprecate( "clip_sample not set", "1.0.0", deprecation_message, standard_warn=False ) new_config = dict(scheduler.config) new_config["clip_sample"] = False scheduler._internal_dict = FrozenDict(new_config) self.register_modules( vae=vae, unet=unet, scheduler=scheduler, tokenizer=tokenizer, text_encoder=text_encoder, ) self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1) self.register_to_config(requires_safety_checker=requires_safety_checker) def enable_vae_slicing(self): r""" Enable sliced VAE decoding. When this option is enabled, the VAE will split the input tensor in slices to compute decoding in several steps. This is useful to save some memory and allow larger batch sizes. """ self.vae.enable_slicing() def disable_vae_slicing(self): r""" Disable sliced VAE decoding. If `enable_vae_slicing` was previously invoked, this method will go back to computing decoding in one step. """ self.vae.disable_slicing() def enable_vae_tiling(self): r""" Enable tiled VAE decoding. When this option is enabled, the VAE will split the input tensor into tiles to compute decoding and encoding in several steps. This is useful to save a large amount of memory and to allow the processing of larger images. """ self.vae.enable_tiling() def disable_vae_tiling(self): r""" Disable tiled VAE decoding. If `enable_vae_tiling` was previously invoked, this method will go back to computing decoding in one step. """ self.vae.disable_tiling() def enable_sequential_cpu_offload(self, gpu_id=0): r""" Offloads all models to CPU using accelerate, significantly reducing memory usage. When called, unet, text_encoder, vae and safety checker have their state dicts saved to CPU and then are moved to a `torch.device('meta') and loaded to GPU only when their specific submodule has its `forward` method called. Note that offloading happens on a submodule basis. Memory savings are higher than with `enable_model_cpu_offload`, but performance is lower. """ if is_accelerate_available() and is_accelerate_version(">=", "0.14.0"): from accelerate import cpu_offload else: raise ImportError( "`enable_sequential_cpu_offload` requires `accelerate v0.14.0` or higher" ) device = torch.device(f"cuda:{gpu_id}") if self.device.type != "cpu": self.to("cpu", silence_dtype_warnings=True) torch.cuda.empty_cache() # otherwise we don't see the memory savings (but they probably exist) for cpu_offloaded_model in [self.unet, self.text_encoder, self.vae]: cpu_offload(cpu_offloaded_model, device) def enable_model_cpu_offload(self, gpu_id=0): r""" Offloads all models to CPU using accelerate, reducing memory usage with a low impact on performance. Compared to `enable_sequential_cpu_offload`, this method moves one whole model at a time to the GPU when its `forward` method is called, and the model remains in GPU until the next model runs. Memory savings are lower than with `enable_sequential_cpu_offload`, but performance is much better due to the iterative execution of the `unet`. """ if is_accelerate_available() and is_accelerate_version(">=", "0.17.0.dev0"): from accelerate import cpu_offload_with_hook else: raise ImportError( "`enable_model_offload` requires `accelerate v0.17.0` or higher." ) device = torch.device(f"cuda:{gpu_id}") if self.device.type != "cpu": self.to("cpu", silence_dtype_warnings=True) torch.cuda.empty_cache() # otherwise we don't see the memory savings (but they probably exist) hook = None for cpu_offloaded_model in [self.text_encoder, self.unet, self.vae]: _, hook = cpu_offload_with_hook( cpu_offloaded_model, device, prev_module_hook=hook ) # We'll offload the last model manually. self.final_offload_hook = hook @property def _execution_device(self): r""" Returns the device on which the pipeline's models will be executed. After calling `pipeline.enable_sequential_cpu_offload()` the execution device can only be inferred from Accelerate's module hooks. """ if not hasattr(self.unet, "_hf_hook"): return self.device for module in self.unet.modules(): if ( hasattr(module, "_hf_hook") and hasattr(module._hf_hook, "execution_device") and module._hf_hook.execution_device is not None ): return torch.device(module._hf_hook.execution_device) return self.device def _encode_prompt( self, prompt, device, num_images_per_prompt, do_classifier_free_guidance: bool, negative_prompt=None, ): r""" Encodes the prompt into text encoder hidden states. Args: prompt (`str` or `List[str]`, *optional*): prompt to be encoded device: (`torch.device`): torch device num_images_per_prompt (`int`): number of images that should be generated per prompt do_classifier_free_guidance (`bool`): whether to use classifier free guidance or not negative_prompt (`str` or `List[str]`, *optional*): The prompt or prompts not to guide the image generation. If not defined, one has to pass `negative_prompt_embeds`. instead. If not defined, one has to pass `negative_prompt_embeds`. instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is less than `1`). prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not provided, text embeddings will be generated from `prompt` input argument. negative_prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated negative text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not provided, negative_prompt_embeds will be generated from `negative_prompt` input argument. """ if prompt is not None and isinstance(prompt, str): batch_size = 1 elif prompt is not None and isinstance(prompt, list): batch_size = len(prompt) else: raise ValueError( f"`prompt` should be either a string or a list of strings, but got {type(prompt)}." ) text_inputs = self.tokenizer( prompt, padding="max_length", max_length=self.tokenizer.model_max_length, truncation=True, return_tensors="pt", ) text_input_ids = text_inputs.input_ids untruncated_ids = self.tokenizer( prompt, padding="longest", return_tensors="pt" ).input_ids if untruncated_ids.shape[-1] >= text_input_ids.shape[-1] and not torch.equal( text_input_ids, untruncated_ids ): removed_text = self.tokenizer.batch_decode( untruncated_ids[:, self.tokenizer.model_max_length - 1 : -1] ) logger.warning( "The following part of your input was truncated because CLIP can only handle sequences up to" f" {self.tokenizer.model_max_length} tokens: {removed_text}" ) if ( hasattr(self.text_encoder.config, "use_attention_mask") and self.text_encoder.config.use_attention_mask ): attention_mask = text_inputs.attention_mask.to(device) else: attention_mask = None prompt_embeds = self.text_encoder( text_input_ids.to(device), attention_mask=attention_mask, ) prompt_embeds = prompt_embeds[0] prompt_embeds = prompt_embeds.to(dtype=self.text_encoder.dtype, device=device) bs_embed, seq_len, _ = prompt_embeds.shape # duplicate text embeddings for each generation per prompt, using mps friendly method prompt_embeds = prompt_embeds.repeat(1, num_images_per_prompt, 1) prompt_embeds = prompt_embeds.view( bs_embed * num_images_per_prompt, seq_len, -1 ) # get unconditional embeddings for classifier free guidance if do_classifier_free_guidance: uncond_tokens: List[str] if negative_prompt is None: uncond_tokens = [""] * batch_size elif type(prompt) is not type(negative_prompt): raise TypeError( f"`negative_prompt` should be the same type to `prompt`, but got {type(negative_prompt)} !=" f" {type(prompt)}." ) elif isinstance(negative_prompt, str): uncond_tokens = [negative_prompt] elif batch_size != len(negative_prompt): raise ValueError( f"`negative_prompt`: {negative_prompt} has batch size {len(negative_prompt)}, but `prompt`:" f" {prompt} has batch size {batch_size}. Please make sure that passed `negative_prompt` matches" " the batch size of `prompt`." ) else: uncond_tokens = negative_prompt max_length = prompt_embeds.shape[1] uncond_input = self.tokenizer( uncond_tokens, padding="max_length", max_length=max_length, truncation=True, return_tensors="pt", ) if ( hasattr(self.text_encoder.config, "use_attention_mask") and self.text_encoder.config.use_attention_mask ): attention_mask = uncond_input.attention_mask.to(device) else: attention_mask = None negative_prompt_embeds = self.text_encoder( uncond_input.input_ids.to(device), attention_mask=attention_mask, ) negative_prompt_embeds = negative_prompt_embeds[0] # duplicate unconditional embeddings for each generation per prompt, using mps friendly method seq_len = negative_prompt_embeds.shape[1] negative_prompt_embeds = negative_prompt_embeds.to( dtype=self.text_encoder.dtype, device=device ) negative_prompt_embeds = negative_prompt_embeds.repeat( 1, num_images_per_prompt, 1 ) negative_prompt_embeds = negative_prompt_embeds.view( batch_size * num_images_per_prompt, seq_len, -1 ) # For classifier free guidance, we need to do two forward passes. # Here we concatenate the unconditional and text embeddings into a single batch # to avoid doing two forward passes prompt_embeds = torch.cat([negative_prompt_embeds, prompt_embeds]) return prompt_embeds def decode_latents(self, latents): latents = 1 / self.vae.config.scaling_factor * latents image = self.vae.decode(latents).sample image = (image / 2 + 0.5).clamp(0, 1) # we always cast to float32 as this does not cause significant overhead and is compatible with bfloat16 image = image.cpu().permute(0, 2, 3, 1).float().numpy() return image def prepare_extra_step_kwargs(self, generator, eta): # prepare extra kwargs for the scheduler step, since not all schedulers have the same signature # eta (η) is only used with the DDIMScheduler, it will be ignored for other schedulers. # eta corresponds to η in DDIM paper: https://arxiv.org/abs/2010.02502 # and should be between [0, 1] accepts_eta = "eta" in set( inspect.signature(self.scheduler.step).parameters.keys() ) extra_step_kwargs = {} if accepts_eta: extra_step_kwargs["eta"] = eta # check if the scheduler accepts generator accepts_generator = "generator" in set( inspect.signature(self.scheduler.step).parameters.keys() ) if accepts_generator: extra_step_kwargs["generator"] = generator return extra_step_kwargs def prepare_latents( self, batch_size, num_channels_latents, height, width, dtype, device, generator, latents=None, ): shape = ( batch_size, num_channels_latents, height // self.vae_scale_factor, width // self.vae_scale_factor, ) if isinstance(generator, list) and len(generator) != batch_size: raise ValueError( f"You have passed a list of generators of length {len(generator)}, but requested an effective batch" f" size of {batch_size}. Make sure the batch size matches the length of the generators." ) if latents is None: latents = randn_tensor( shape, generator=generator, device=device, dtype=dtype ) else: latents = latents.to(device) # scale the initial noise by the standard deviation required by the scheduler latents = latents * self.scheduler.init_noise_sigma return latents @torch.no_grad() def __call__( self, prompt: str = "a car", height: int = 256, width: int = 256, num_inference_steps: int = 50, guidance_scale: float = 7.0, negative_prompt: str = "bad quality", num_images_per_prompt: int = 1, eta: float = 0.0, generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None, output_type: Optional[str] = "image", callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None, callback_steps: int = 1, batch_size: int = 4, device=torch.device("cuda:0"), ): self.unet = self.unet.to(device=device) self.vae = self.vae.to(device=device) self.text_encoder = self.text_encoder.to(device=device) # here `guidance_scale` is defined analog to the guidance weight `w` of equation (2) # of the Imagen paper: https://arxiv.org/pdf/2205.11487.pdf . `guidance_scale = 1` # corresponds to doing no classifier free guidance. do_classifier_free_guidance = guidance_scale > 1.0 # Prepare timesteps self.scheduler.set_timesteps(num_inference_steps, device=device) timesteps = self.scheduler.timesteps _prompt_embeds: torch.Tensor = self._encode_prompt( prompt=prompt, device=device, num_images_per_prompt=num_images_per_prompt, do_classifier_free_guidance=do_classifier_free_guidance, negative_prompt=negative_prompt, ) # type: ignore prompt_embeds_neg, prompt_embeds_pos = _prompt_embeds.chunk(2) # Prepare latent variables latents: torch.Tensor = self.prepare_latents( batch_size * num_images_per_prompt, 4, height, width, prompt_embeds_pos.dtype, device, generator, None, ) camera = get_camera(batch_size).to(dtype=latents.dtype, device=device) # Prepare extra step kwargs. TODO: Logic should ideally just be moved out of the pipeline extra_step_kwargs = self.prepare_extra_step_kwargs(generator, eta) # Denoising loop num_warmup_steps = len(timesteps) - num_inference_steps * self.scheduler.order with self.progress_bar(total=num_inference_steps) as progress_bar: for i, t in enumerate(timesteps): # expand the latents if we are doing classifier free guidance multiplier = 2 if do_classifier_free_guidance else 1 latent_model_input = torch.cat([latents] * multiplier) latent_model_input = self.scheduler.scale_model_input( latent_model_input, t ) # predict the noise residual noise_pred = self.unet.forward( x=latent_model_input, timesteps=torch.tensor( [t] * 4 * multiplier, dtype=latent_model_input.dtype, device=device, ), context=torch.cat( [prompt_embeds_neg] * 4 + [prompt_embeds_pos] * 4 ), num_frames=4, camera=torch.cat([camera] * multiplier), ) # perform guidance if do_classifier_free_guidance: noise_pred_uncond, noise_pred_text = noise_pred.chunk(2) noise_pred = noise_pred_uncond + guidance_scale * ( noise_pred_text - noise_pred_uncond ) # compute the previous noisy sample x_t -> x_t-1 # latents = self.scheduler.step(noise_pred.to(dtype=torch.float32), t, latents.to(dtype=torch.float32)).prev_sample.to(prompt_embeds.dtype) latents: torch.Tensor = self.scheduler.step( noise_pred, t, latents, **extra_step_kwargs, return_dict=False )[0] # call the callback, if provided if i == len(timesteps) - 1 or ( (i + 1) > num_warmup_steps and (i + 1) % self.scheduler.order == 0 ): progress_bar.update() if callback is not None and i % callback_steps == 0: callback(i, t, latents) # type: ignore # Post-processing if output_type == "latent": image = latents elif output_type == "pil": image = self.decode_latents(latents) image = self.numpy_to_pil(image) else: image = self.decode_latents(latents) # Offload last model to CPU if hasattr(self, "final_offload_hook") and self.final_offload_hook is not None: self.final_offload_hook.offload() return image