Add support for Chroma Radiance (#9682)

* Initial Chroma Radiance support

* Minor Chroma Radiance cleanups

* Update Radiance nodes to ensure latents/images are on the intermediate device

* Fix Chroma Radiance memory estimation.

* Increase Chroma Radiance memory usage factor

* Increase Chroma Radiance memory usage factor once again

* Ensure images are multiples of 16 for Chroma Radiance
Add batch dimension and fix channels when necessary in ChromaRadianceImageToLatent node

* Tile Chroma Radiance NeRF to reduce memory consumption, update memory usage factor

* Update Radiance to support conv nerf final head type.

* Allow setting NeRF embedder dtype for Radiance
Bump Radiance nerf tile size to 32
Support EasyCache/LazyCache on Radiance (maybe)

* Add ChromaRadianceStubVAE node

* Crop Radiance image inputs to multiples of 16 instead of erroring to be in line with existing VAE behavior

* Convert Chroma Radiance nodes to V3 schema.

* Add ChromaRadianceOptions node and backend support.
Cleanups/refactoring to reduce code duplication with Chroma.

* Fix overriding the NeRF embedder dtype for Chroma Radiance

* Minor Chroma Radiance cleanups

* Move Chroma Radiance to its own directory in ldm
Minor code cleanups and tooltip improvements

* Fix Chroma Radiance embedder dtype overriding

* Remove Radiance dynamic nerf_embedder dtype override feature

* Unbork Radiance NeRF embedder init

* Remove Chroma Radiance image conversion and stub VAE nodes
Add a chroma_radiance option to the VAELoader builtin node which uses comfy.sd.PixelspaceConversionVAE
Add a PixelspaceConversionVAE to comfy.sd for converting BHWC 0..1 <-> BCHW -1..1

comfy/latent_formats.py

@@ -629,3 +629,20 @@ class Hunyuan3Dv2mini(LatentFormat):
 class ACEAudio(LatentFormat):
     latent_channels = 8
     latent_dimensions = 2
+
+class ChromaRadiance(LatentFormat):
+    latent_channels = 3
+
+    def __init__(self):
+        self.latent_rgb_factors = [
+            # R    G    B
+            [ 1.0, 0.0, 0.0 ],
+            [ 0.0, 1.0, 0.0 ],
+            [ 0.0, 0.0, 1.0 ]
+        ]
+
+    def process_in(self, latent):
+        return latent
+
+    def process_out(self, latent):
+        return latent

comfy/ldm/chroma/model.py

@@ -151,8 +151,6 @@ class Chroma(nn.Module):
         attn_mask: Tensor = None,
     ) -> Tensor:
         patches_replace = transformer_options.get("patches_replace", {})
-        if img.ndim != 3 or txt.ndim != 3:
-            raise ValueError("Input img and txt tensors must have 3 dimensions.")
 
         # running on sequences img
         img = self.img_in(img)
@@ -254,8 +252,9 @@ class Chroma(nn.Module):
                             img[:, txt.shape[1] :, ...] += add
 
         img = img[:, txt.shape[1] :, ...]
-        final_mod = self.get_modulations(mod_vectors, "final")
-        img = self.final_layer(img, vec=final_mod)  # (N, T, patch_size ** 2 * out_channels)
+        if hasattr(self, "final_layer"):
+            final_mod = self.get_modulations(mod_vectors, "final")
+            img = self.final_layer(img, vec=final_mod)  # (N, T, patch_size ** 2 * out_channels)
         return img
 
     def forward(self, x, timestep, context, guidance, control=None, transformer_options={}, **kwargs):
@@ -271,6 +270,9 @@ class Chroma(nn.Module):
 
         img = rearrange(x, "b c (h ph) (w pw) -> b (h w) (c ph pw)", ph=self.patch_size, pw=self.patch_size)
 
+        if img.ndim != 3 or context.ndim != 3:
+            raise ValueError("Input img and txt tensors must have 3 dimensions.")
+
         h_len = ((h + (self.patch_size // 2)) // self.patch_size)
         w_len = ((w + (self.patch_size // 2)) // self.patch_size)
         img_ids = torch.zeros((h_len, w_len, 3), device=x.device, dtype=x.dtype)

comfy/ldm/chroma_radiance/layers.py

@@ -0,0 +1,206 @@
+# Adapted from https://github.com/lodestone-rock/flow
+from functools import lru_cache
+
+import torch
+from torch import nn
+
+from comfy.ldm.flux.layers import RMSNorm
+
+
+class NerfEmbedder(nn.Module):
+    """
+    An embedder module that combines input features with a 2D positional
+    encoding that mimics the Discrete Cosine Transform (DCT).
+
+    This module takes an input tensor of shape (B, P^2, C), where P is the
+    patch size, and enriches it with positional information before projecting
+    it to a new hidden size.
+    """
+    def __init__(
+        self,
+        in_channels: int,
+        hidden_size_input: int,
+        max_freqs: int,
+        dtype=None,
+        device=None,
+        operations=None,
+    ):
+        """
+        Initializes the NerfEmbedder.
+
+        Args:
+            in_channels (int): The number of channels in the input tensor.
+            hidden_size_input (int): The desired dimension of the output embedding.
+            max_freqs (int): The number of frequency components to use for both
+                             the x and y dimensions of the positional encoding.
+                             The total number of positional features will be max_freqs^2.
+        """
+        super().__init__()
+        self.dtype = dtype
+        self.max_freqs = max_freqs
+        self.hidden_size_input = hidden_size_input
+
+        # A linear layer to project the concatenated input features and
+        # positional encodings to the final output dimension.
+        self.embedder = nn.Sequential(
+            operations.Linear(in_channels + max_freqs**2, hidden_size_input, dtype=dtype, device=device)
+        )
+
+    @lru_cache(maxsize=4)
+    def fetch_pos(self, patch_size: int, device: torch.device, dtype: torch.dtype) -> torch.Tensor:
+        """
+        Generates and caches 2D DCT-like positional embeddings for a given patch size.
+
+        The LRU cache is a performance optimization that avoids recomputing the
+        same positional grid on every forward pass.
+
+        Args:
+            patch_size (int): The side length of the square input patch.
+            device: The torch device to create the tensors on.
+            dtype: The torch dtype for the tensors.
+
+        Returns:
+            A tensor of shape (1, patch_size^2, max_freqs^2) containing the
+            positional embeddings.
+        """
+        # Create normalized 1D coordinate grids from 0 to 1.
+        pos_x = torch.linspace(0, 1, patch_size, device=device, dtype=dtype)
+        pos_y = torch.linspace(0, 1, patch_size, device=device, dtype=dtype)
+
+        # Create a 2D meshgrid of coordinates.
+        pos_y, pos_x = torch.meshgrid(pos_y, pos_x, indexing="ij")
+
+        # Reshape positions to be broadcastable with frequencies.
+        # Shape becomes (patch_size^2, 1, 1).
+        pos_x = pos_x.reshape(-1, 1, 1)
+        pos_y = pos_y.reshape(-1, 1, 1)
+
+        # Create a 1D tensor of frequency values from 0 to max_freqs-1.
+        freqs = torch.linspace(0, self.max_freqs - 1, self.max_freqs, dtype=dtype, device=device)
+
+        # Reshape frequencies to be broadcastable for creating 2D basis functions.
+        # freqs_x shape: (1, max_freqs, 1)
+        # freqs_y shape: (1, 1, max_freqs)
+        freqs_x = freqs[None, :, None]
+        freqs_y = freqs[None, None, :]
+
+        # A custom weighting coefficient, not part of standard DCT.
+        # This seems to down-weight the contribution of higher-frequency interactions.
+        coeffs = (1 + freqs_x * freqs_y) ** -1
+
+        # Calculate the 1D cosine basis functions for x and y coordinates.
+        # This is the core of the DCT formulation.
+        dct_x = torch.cos(pos_x * freqs_x * torch.pi)
+        dct_y = torch.cos(pos_y * freqs_y * torch.pi)
+
+        # Combine the 1D basis functions to create 2D basis functions by element-wise
+        # multiplication, and apply the custom coefficients. Broadcasting handles the
+        # combination of all (pos_x, freqs_x) with all (pos_y, freqs_y).
+        # The result is flattened into a feature vector for each position.
+        dct = (dct_x * dct_y * coeffs).view(1, -1, self.max_freqs ** 2)
+
+        return dct
+
+    def forward(self, inputs: torch.Tensor) -> torch.Tensor:
+        """
+        Forward pass for the embedder.
+
+        Args:
+            inputs (Tensor): The input tensor of shape (B, P^2, C).
+
+        Returns:
+            Tensor: The output tensor of shape (B, P^2, hidden_size_input).
+        """
+        # Get the batch size, number of pixels, and number of channels.
+        B, P2, C = inputs.shape
+
+        # Infer the patch side length from the number of pixels (P^2).
+        patch_size = int(P2 ** 0.5)
+
+        input_dtype = inputs.dtype
+        inputs = inputs.to(dtype=self.dtype)
+
+        # Fetch the pre-computed or cached positional embeddings.
+        dct = self.fetch_pos(patch_size, inputs.device, self.dtype)
+
+        # Repeat the positional embeddings for each item in the batch.
+        dct = dct.repeat(B, 1, 1)
+
+        # Concatenate the original input features with the positional embeddings
+        # along the feature dimension.
+        inputs = torch.cat((inputs, dct), dim=-1)
+
+        # Project the combined tensor to the target hidden size.
+        return self.embedder(inputs).to(dtype=input_dtype)
+
+
+class NerfGLUBlock(nn.Module):
+    """
+    A NerfBlock using a Gated Linear Unit (GLU) like MLP.
+    """
+    def __init__(self, hidden_size_s: int, hidden_size_x: int, mlp_ratio, dtype=None, device=None, operations=None):
+        super().__init__()
+        # The total number of parameters for the MLP is increased to accommodate
+        # the gate, value, and output projection matrices.
+        # We now need to generate parameters for 3 matrices.
+        total_params = 3 * hidden_size_x**2 * mlp_ratio
+        self.param_generator = operations.Linear(hidden_size_s, total_params, dtype=dtype, device=device)
+        self.norm = RMSNorm(hidden_size_x, dtype=dtype, device=device, operations=operations)
+        self.mlp_ratio = mlp_ratio
+
+
+    def forward(self, x: torch.Tensor, s: torch.Tensor) -> torch.Tensor:
+        batch_size, num_x, hidden_size_x = x.shape
+        mlp_params = self.param_generator(s)
+
+        # Split the generated parameters into three parts for the gate, value, and output projection.
+        fc1_gate_params, fc1_value_params, fc2_params = mlp_params.chunk(3, dim=-1)
+
+        # Reshape the parameters into matrices for batch matrix multiplication.
+        fc1_gate = fc1_gate_params.view(batch_size, hidden_size_x, hidden_size_x * self.mlp_ratio)
+        fc1_value = fc1_value_params.view(batch_size, hidden_size_x, hidden_size_x * self.mlp_ratio)
+        fc2 = fc2_params.view(batch_size, hidden_size_x * self.mlp_ratio, hidden_size_x)
+
+        # Normalize the generated weight matrices as in the original implementation.
+        fc1_gate = torch.nn.functional.normalize(fc1_gate, dim=-2)
+        fc1_value = torch.nn.functional.normalize(fc1_value, dim=-2)
+        fc2 = torch.nn.functional.normalize(fc2, dim=-2)
+
+        res_x = x
+        x = self.norm(x)
+
+        # Apply the final output projection.
+        x = torch.bmm(torch.nn.functional.silu(torch.bmm(x, fc1_gate)) * torch.bmm(x, fc1_value), fc2)
+
+        return x + res_x
+
+
+class NerfFinalLayer(nn.Module):
+    def __init__(self, hidden_size, out_channels, dtype=None, device=None, operations=None):
+        super().__init__()
+        self.norm = RMSNorm(hidden_size, dtype=dtype, device=device, operations=operations)
+        self.linear = operations.Linear(hidden_size, out_channels, dtype=dtype, device=device)
+
+    def forward(self, x: torch.Tensor) -> torch.Tensor:
+        # RMSNorm normalizes over the last dimension, but our channel dim (C) is at dim=1.
+        # So we temporarily move the channel dimension to the end for the norm operation.
+        return self.linear(self.norm(x.movedim(1, -1))).movedim(-1, 1)
+
+
+class NerfFinalLayerConv(nn.Module):
+    def __init__(self, hidden_size: int, out_channels: int, dtype=None, device=None, operations=None):
+        super().__init__()
+        self.norm = RMSNorm(hidden_size, dtype=dtype, device=device, operations=operations)
+        self.conv = operations.Conv2d(
+            in_channels=hidden_size,
+            out_channels=out_channels,
+            kernel_size=3,
+            padding=1,
+            dtype=dtype,
+            device=device,
+        )
+
+    def forward(self, x: torch.Tensor) -> torch.Tensor:
+        # RMSNorm normalizes over the last dimension, but our channel dim (C) is at dim=1.
+        # So we temporarily move the channel dimension to the end for the norm operation.
+        return self.conv(self.norm(x.movedim(1, -1)).movedim(-1, 1))

comfy/ldm/chroma_radiance/model.py

@@ -0,0 +1,328 @@
+# Credits:
+# Original Flux code can be found on: https://github.com/black-forest-labs/flux
+# Chroma Radiance adaption referenced from https://github.com/lodestone-rock/flow
+
+from dataclasses import dataclass
+from typing import Optional
+
+import torch
+from torch import Tensor, nn
+from einops import repeat
+import comfy.ldm.common_dit
+
+from comfy.ldm.flux.layers import EmbedND
+
+from comfy.ldm.chroma.model import Chroma, ChromaParams
+from comfy.ldm.chroma.layers import (
+    DoubleStreamBlock,
+    SingleStreamBlock,
+    Approximator,
+)
+from .layers import (
+    NerfEmbedder,
+    NerfGLUBlock,
+    NerfFinalLayer,
+    NerfFinalLayerConv,
+)
+
+
+@dataclass
+class ChromaRadianceParams(ChromaParams):
+    patch_size: int
+    nerf_hidden_size: int
+    nerf_mlp_ratio: int
+    nerf_depth: int
+    nerf_max_freqs: int
+    # Setting nerf_tile_size to 0 disables tiling.
+    nerf_tile_size: int
+    # Currently one of linear (legacy) or conv.
+    nerf_final_head_type: str
+    # None means use the same dtype as the model.
+    nerf_embedder_dtype: Optional[torch.dtype]
+
+
+class ChromaRadiance(Chroma):
+    """
+    Transformer model for flow matching on sequences.
+    """
+
+    def __init__(self, image_model=None, final_layer=True, dtype=None, device=None, operations=None, **kwargs):
+        if operations is None:
+            raise RuntimeError("Attempt to create ChromaRadiance object without setting operations")
+        nn.Module.__init__(self)
+        self.dtype = dtype
+        params = ChromaRadianceParams(**kwargs)
+        self.params = params
+        self.patch_size = params.patch_size
+        self.in_channels = params.in_channels
+        self.out_channels = params.out_channels
+        if params.hidden_size % params.num_heads != 0:
+            raise ValueError(
+                f"Hidden size {params.hidden_size} must be divisible by num_heads {params.num_heads}"
+            )
+        pe_dim = params.hidden_size // params.num_heads
+        if sum(params.axes_dim) != pe_dim:
+            raise ValueError(f"Got {params.axes_dim} but expected positional dim {pe_dim}")
+        self.hidden_size = params.hidden_size
+        self.num_heads = params.num_heads
+        self.in_dim = params.in_dim
+        self.out_dim = params.out_dim
+        self.hidden_dim = params.hidden_dim
+        self.n_layers = params.n_layers
+        self.pe_embedder = EmbedND(dim=pe_dim, theta=params.theta, axes_dim=params.axes_dim)
+        self.img_in_patch = operations.Conv2d(
+            params.in_channels,
+            params.hidden_size,
+            kernel_size=params.patch_size,
+            stride=params.patch_size,
+            bias=True,
+            dtype=dtype,
+            device=device,
+        )
+        self.txt_in = operations.Linear(params.context_in_dim, self.hidden_size, dtype=dtype, device=device)
+        # set as nn identity for now, will overwrite it later.
+        self.distilled_guidance_layer = Approximator(
+                    in_dim=self.in_dim,
+                    hidden_dim=self.hidden_dim,
+                    out_dim=self.out_dim,
+                    n_layers=self.n_layers,
+                    dtype=dtype, device=device, operations=operations
+                )
+
+
+        self.double_blocks = nn.ModuleList(
+            [
+                DoubleStreamBlock(
+                    self.hidden_size,
+                    self.num_heads,
+                    mlp_ratio=params.mlp_ratio,
+                    qkv_bias=params.qkv_bias,
+                    dtype=dtype, device=device, operations=operations
+                )
+                for _ in range(params.depth)
+            ]
+        )
+
+        self.single_blocks = nn.ModuleList(
+            [
+                SingleStreamBlock(
+                    self.hidden_size,
+                    self.num_heads,
+                    mlp_ratio=params.mlp_ratio,
+                    dtype=dtype, device=device, operations=operations,
+                )
+                for _ in range(params.depth_single_blocks)
+            ]
+        )
+
+        # pixel channel concat with DCT
+        self.nerf_image_embedder = NerfEmbedder(
+            in_channels=params.in_channels,
+            hidden_size_input=params.nerf_hidden_size,
+            max_freqs=params.nerf_max_freqs,
+            dtype=params.nerf_embedder_dtype or dtype,
+            device=device,
+            operations=operations,
+        )
+
+        self.nerf_blocks = nn.ModuleList([
+            NerfGLUBlock(
+                hidden_size_s=params.hidden_size,
+                hidden_size_x=params.nerf_hidden_size,
+                mlp_ratio=params.nerf_mlp_ratio,
+                dtype=dtype,
+                device=device,
+                operations=operations,
+            ) for _ in range(params.nerf_depth)
+        ])
+
+        if params.nerf_final_head_type == "linear":
+            self.nerf_final_layer = NerfFinalLayer(
+                params.nerf_hidden_size,
+                out_channels=params.in_channels,
+                dtype=dtype,
+                device=device,
+                operations=operations,
+            )
+        elif params.nerf_final_head_type == "conv":
+            self.nerf_final_layer_conv = NerfFinalLayerConv(
+                params.nerf_hidden_size,
+                out_channels=params.in_channels,
+                dtype=dtype,
+                device=device,
+                operations=operations,
+            )
+        else:
+            errstr = f"Unsupported nerf_final_head_type {params.nerf_final_head_type}"
+            raise ValueError(errstr)
+
+        self.skip_mmdit = []
+        self.skip_dit = []
+        self.lite = False
+
+    @property
+    def _nerf_final_layer(self) -> nn.Module:
+        if self.params.nerf_final_head_type == "linear":
+            return self.nerf_final_layer
+        if self.params.nerf_final_head_type == "conv":
+            return self.nerf_final_layer_conv
+        # Impossible to get here as we raise an error on unexpected types on initialization.
+        raise NotImplementedError
+
+    def img_in(self, img: Tensor) -> Tensor:
+        img = self.img_in_patch(img) # -> [B, Hidden, H/P, W/P]
+        # flatten into a sequence for the transformer.
+        return img.flatten(2).transpose(1, 2) # -> [B, NumPatches, Hidden]
+
+    def forward_nerf(
+        self,
+        img_orig: Tensor,
+        img_out: Tensor,
+        params: ChromaRadianceParams,
+    ) -> Tensor:
+        B, C, H, W = img_orig.shape
+        num_patches = img_out.shape[1]
+        patch_size = params.patch_size
+
+        # Store the raw pixel values of each patch for the NeRF head later.
+        # unfold creates patches: [B, C * P * P, NumPatches]
+        nerf_pixels = nn.functional.unfold(img_orig, kernel_size=patch_size, stride=patch_size)
+        nerf_pixels = nerf_pixels.transpose(1, 2) # -> [B, NumPatches, C * P * P]
+
+        if params.nerf_tile_size > 0 and num_patches > params.nerf_tile_size:
+            # Enable tiling if nerf_tile_size isn't 0 and we actually have more patches than
+            # the tile size.
+            img_dct = self.forward_tiled_nerf(img_out, nerf_pixels, B, C, num_patches, patch_size, params)
+        else:
+            # Reshape for per-patch processing
+            nerf_hidden = img_out.reshape(B * num_patches, params.hidden_size)
+            nerf_pixels = nerf_pixels.reshape(B * num_patches, C, patch_size**2).transpose(1, 2)
+
+            # Get DCT-encoded pixel embeddings [pixel-dct]
+            img_dct = self.nerf_image_embedder(nerf_pixels)
+
+            # Pass through the dynamic MLP blocks (the NeRF)
+            for block in self.nerf_blocks:
+                img_dct = block(img_dct, nerf_hidden)
+
+        # Reassemble the patches into the final image.
+        img_dct = img_dct.transpose(1, 2) # -> [B*NumPatches, C, P*P]
+        # Reshape to combine with batch dimension for fold
+        img_dct = img_dct.reshape(B, num_patches, -1) # -> [B, NumPatches, C*P*P]
+        img_dct = img_dct.transpose(1, 2) # -> [B, C*P*P, NumPatches]
+        img_dct = nn.functional.fold(
+            img_dct,
+            output_size=(H, W),
+            kernel_size=patch_size,
+            stride=patch_size,
+        )
+        return self._nerf_final_layer(img_dct)
+
+    def forward_tiled_nerf(
+        self,
+        nerf_hidden: Tensor,
+        nerf_pixels: Tensor,
+        batch: int,
+        channels: int,
+        num_patches: int,
+        patch_size: int,
+        params: ChromaRadianceParams,
+    ) -> Tensor:
+        """
+        Processes the NeRF head in tiles to save memory.
+        nerf_hidden has shape [B, L, D]
+        nerf_pixels has shape [B, L, C * P * P]
+        """
+        tile_size = params.nerf_tile_size
+        output_tiles = []
+        # Iterate over the patches in tiles. The dimension L (num_patches) is at index 1.
+        for i in range(0, num_patches, tile_size):
+            end = min(i + tile_size, num_patches)
+
+            # Slice the current tile from the input tensors
+            nerf_hidden_tile = nerf_hidden[:, i:end, :]
+            nerf_pixels_tile = nerf_pixels[:, i:end, :]
+
+            # Get the actual number of patches in this tile (can be smaller for the last tile)
+            num_patches_tile = nerf_hidden_tile.shape[1]
+
+            # Reshape the tile for per-patch processing
+            # [B, NumPatches_tile, D] -> [B * NumPatches_tile, D]
+            nerf_hidden_tile = nerf_hidden_tile.reshape(batch * num_patches_tile, params.hidden_size)
+            # [B, NumPatches_tile, C*P*P] -> [B*NumPatches_tile, C, P*P] -> [B*NumPatches_tile, P*P, C]
+            nerf_pixels_tile = nerf_pixels_tile.reshape(batch * num_patches_tile, channels, patch_size**2).transpose(1, 2)
+
+            # get DCT-encoded pixel embeddings [pixel-dct]
+            img_dct_tile = self.nerf_image_embedder(nerf_pixels_tile)
+
+            # pass through the dynamic MLP blocks (the NeRF)
+            for block in self.nerf_blocks:
+                img_dct_tile = block(img_dct_tile, nerf_hidden_tile)
+
+            output_tiles.append(img_dct_tile)
+
+        # Concatenate the processed tiles along the patch dimension
+        return torch.cat(output_tiles, dim=0)
+
+    def radiance_get_override_params(self, overrides: dict) -> ChromaRadianceParams:
+        params = self.params
+        if not overrides:
+            return params
+        params_dict = {k: getattr(params, k) for k in params.__dataclass_fields__}
+        nullable_keys = frozenset(("nerf_embedder_dtype",))
+        bad_keys = tuple(k for k in overrides if k not in params_dict)
+        if bad_keys:
+            e = f"Unknown key(s) in transformer_options chroma_radiance_options: {', '.join(bad_keys)}"
+            raise ValueError(e)
+        bad_keys = tuple(
+            k
+            for k, v in overrides.items()
+            if type(v) != type(getattr(params, k)) and (v is not None or k not in nullable_keys)
+        )
+        if bad_keys:
+            e = f"Invalid value(s) in transformer_options chroma_radiance_options: {', '.join(bad_keys)}"
+            raise ValueError(e)
+        # At this point it's all valid keys and values so we can merge with the existing params.
+        params_dict |= overrides
+        return params.__class__(**params_dict)
+
+    def _forward(
+        self,
+        x: Tensor,
+        timestep: Tensor,
+        context: Tensor,
+        guidance: Optional[Tensor],
+        control: Optional[dict]=None,
+        transformer_options: dict={},
+        **kwargs: dict,
+    ) -> Tensor:
+        bs, c, h, w = x.shape
+        img = comfy.ldm.common_dit.pad_to_patch_size(x, (self.patch_size, self.patch_size))
+
+        if img.ndim != 4:
+            raise ValueError("Input img tensor must be in [B, C, H, W] format.")
+        if context.ndim != 3:
+            raise ValueError("Input txt tensors must have 3 dimensions.")
+
+        params = self.radiance_get_override_params(transformer_options.get("chroma_radiance_options", {}))
+
+        h_len = ((h + (self.patch_size // 2)) // self.patch_size)
+        w_len = ((w + (self.patch_size // 2)) // self.patch_size)
+        img_ids = torch.zeros((h_len, w_len, 3), device=x.device, dtype=x.dtype)
+        img_ids[:, :, 1] = img_ids[:, :, 1] + torch.linspace(0, h_len - 1, steps=h_len, device=x.device, dtype=x.dtype).unsqueeze(1)
+        img_ids[:, :, 2] = img_ids[:, :, 2] + torch.linspace(0, w_len - 1, steps=w_len, device=x.device, dtype=x.dtype).unsqueeze(0)
+        img_ids = repeat(img_ids, "h w c -> b (h w) c", b=bs)
+        txt_ids = torch.zeros((bs, context.shape[1], 3), device=x.device, dtype=x.dtype)
+
+        img_out = self.forward_orig(
+            img,
+            img_ids,
+            context,
+            txt_ids,
+            timestep,
+            guidance,
+            control,
+            transformer_options,
+            attn_mask=kwargs.get("attention_mask", None),
+        )
+        return self.forward_nerf(img, img_out, params)

comfy/model_base.py

@@ -42,6 +42,7 @@ import comfy.ldm.wan.model
 import comfy.ldm.hunyuan3d.model
 import comfy.ldm.hidream.model
 import comfy.ldm.chroma.model
+import comfy.ldm.chroma_radiance.model
 import comfy.ldm.ace.model
 import comfy.ldm.omnigen.omnigen2
 import comfy.ldm.qwen_image.model
@@ -1320,8 +1321,8 @@ class HiDream(BaseModel):
         return out
 
 class Chroma(Flux):
-    def __init__(self, model_config, model_type=ModelType.FLUX, device=None):
-        super().__init__(model_config, model_type, device=device, unet_model=comfy.ldm.chroma.model.Chroma)
+    def __init__(self, model_config, model_type=ModelType.FLUX, device=None, unet_model=comfy.ldm.chroma.model.Chroma):
+        super().__init__(model_config, model_type, device=device, unet_model=unet_model)
 
     def extra_conds(self, **kwargs):
         out = super().extra_conds(**kwargs)
@@ -1331,6 +1332,10 @@ class Chroma(Flux):
             out['guidance'] = comfy.conds.CONDRegular(torch.FloatTensor([guidance]))
         return out
 
+class ChromaRadiance(Chroma):
+    def __init__(self, model_config, model_type=ModelType.FLUX, device=None):
+        super().__init__(model_config, model_type, device=device, unet_model=comfy.ldm.chroma_radiance.model.ChromaRadiance)
+
 class ACEStep(BaseModel):
     def __init__(self, model_config, model_type=ModelType.FLOW, device=None):
         super().__init__(model_config, model_type, device=device, unet_model=comfy.ldm.ace.model.ACEStepTransformer2DModel)

comfy/model_detection.py

@@ -174,7 +174,7 @@ def detect_unet_config(state_dict, key_prefix, metadata=None):
         dit_config["guidance_embed"] = len(guidance_keys) > 0
         return dit_config
 
-    if '{}double_blocks.0.img_attn.norm.key_norm.scale'.format(key_prefix) in state_dict_keys and '{}img_in.weight'.format(key_prefix) in state_dict_keys: #Flux
+    if '{}double_blocks.0.img_attn.norm.key_norm.scale'.format(key_prefix) in state_dict_keys and ('{}img_in.weight'.format(key_prefix) in state_dict_keys or f"{key_prefix}distilled_guidance_layer.norms.0.scale" in state_dict_keys): #Flux, Chroma or Chroma Radiance (has no img_in.weight)
         dit_config = {}
         dit_config["image_model"] = "flux"
         dit_config["in_channels"] = 16
@@ -204,6 +204,18 @@ def detect_unet_config(state_dict, key_prefix, metadata=None):
             dit_config["out_dim"] = 3072
             dit_config["hidden_dim"] = 5120
             dit_config["n_layers"] = 5
+            if f"{key_prefix}nerf_blocks.0.norm.scale" in state_dict_keys: #Chroma Radiance
+                dit_config["image_model"] = "chroma_radiance"
+                dit_config["in_channels"] = 3
+                dit_config["out_channels"] = 3
+                dit_config["patch_size"] = 16
+                dit_config["nerf_hidden_size"] = 64
+                dit_config["nerf_mlp_ratio"] = 4
+                dit_config["nerf_depth"] = 4
+                dit_config["nerf_max_freqs"] = 8
+                dit_config["nerf_tile_size"] = 32
+                dit_config["nerf_final_head_type"] = "conv" if f"{key_prefix}nerf_final_layer_conv.norm.scale" in state_dict_keys else "linear"
+                dit_config["nerf_embedder_dtype"] = torch.float32
         else:
             dit_config["guidance_embed"] = "{}guidance_in.in_layer.weight".format(key_prefix) in state_dict_keys
         return dit_config

comfy/sd.py

@@ -785,6 +785,66 @@ class VAE:
         except:
             return None
 
+# "Fake" VAE that converts from IMAGE B, H, W, C and values on the scale of 0..1
+# to LATENT B, C, H, W and values on the scale of -1..1.
+class PixelspaceConversionVAE:
+    def __init__(self, size_increment: int=16):
+        self.intermediate_device = comfy.model_management.intermediate_device()
+        self.size_increment = size_increment
+
+    def vae_encode_crop_pixels(self, pixels: torch.Tensor) -> torch.Tensor:
+        if self.size_increment == 1:
+            return pixels
+        dims = pixels.shape[1:-1]
+        for d in range(len(dims)):
+            d_adj = (dims[d] // self.size_increment) * self.size_increment
+            if d_adj == d:
+                continue
+            d_offset = (dims[d] % self.size_increment) // 2
+            pixels = pixels.narrow(d + 1, d_offset, d_adj)
+        return pixels
+
+    def encode(self, pixels: torch.Tensor, *_args, **_kwargs) -> torch.Tensor:
+        if pixels.ndim == 3:
+            pixels = pixels.unsqueeze(0)
+        elif pixels.ndim != 4:
+            raise ValueError("Unexpected input image shape")
+        # Ensure the image has spatial dimensions that are multiples of 16.
+        pixels = self.vae_encode_crop_pixels(pixels)
+        h, w, c = pixels.shape[1:]
+        if h < self.size_increment or w < self.size_increment:
+            raise ValueError(f"Image inputs must have height/width of at least {self.size_increment} pixel(s).")
+        pixels= pixels[..., :3]
+        if c == 1:
+            pixels = pixels.expand(-1, -1, -1, 3)
+        elif c != 3:
+            raise ValueError("Unexpected number of channels in input image")
+        # Rescale to -1..1 and move the channel dimension to position 1.
+        latent = pixels.to(device=self.intermediate_device, dtype=torch.float32, copy=True)
+        latent = latent.clamp_(0, 1).movedim(-1, 1).contiguous()
+        latent -= 0.5
+        latent *= 2
+        return latent.clamp_(-1, 1)
+
+    def decode(self, samples: torch.Tensor, *_args, **_kwargs) -> torch.Tensor:
+        # Rescale to 0..1 and move the channel dimension to the end.
+        img = samples.to(device=self.intermediate_device, dtype=torch.float32, copy=True)
+        img = img.clamp_(-1, 1).movedim(1, -1).contiguous()
+        img += 1.0
+        img *= 0.5
+        return img.clamp_(0, 1)
+
+    encode_tiled = encode
+    decode_tiled = decode
+
+    @classmethod
+    def spacial_compression_decode(cls) -> int:
+        # This just exists so the tiled VAE nodes don't crash.
+        return 1
+
+    spacial_compression_encode = spacial_compression_decode
+    temporal_compression_decode = spacial_compression_decode
+
 class StyleModel:
     def __init__(self, model, device="cpu"):
         self.model = model

comfy/supported_models.py

@@ -1205,6 +1205,19 @@ class Chroma(supported_models_base.BASE):
         t5_detect = comfy.text_encoders.sd3_clip.t5_xxl_detect(state_dict, "{}t5xxl.transformer.".format(pref))
         return supported_models_base.ClipTarget(comfy.text_encoders.pixart_t5.PixArtTokenizer, comfy.text_encoders.pixart_t5.pixart_te(**t5_detect))
 
+class ChromaRadiance(Chroma):
+    unet_config = {
+        "image_model": "chroma_radiance",
+    }
+
+    latent_format = comfy.latent_formats.ChromaRadiance
+
+    # Pixel-space model, no spatial compression for model input.
+    memory_usage_factor = 0.0325
+
+    def get_model(self, state_dict, prefix="", device=None):
+        return model_base.ChromaRadiance(self, device=device)
+
 class ACEStep(supported_models_base.BASE):
     unet_config = {
         "audio_model": "ace",
@@ -1338,6 +1351,6 @@ class HunyuanImage21Refiner(HunyuanVideo):
         out = model_base.HunyuanImage21Refiner(self, device=device)
         return out
 
-models = [LotusD, Stable_Zero123, SD15_instructpix2pix, SD15, SD20, SD21UnclipL, SD21UnclipH, SDXL_instructpix2pix, SDXLRefiner, SDXL, SSD1B, KOALA_700M, KOALA_1B, Segmind_Vega, SD_X4Upscaler, Stable_Cascade_C, Stable_Cascade_B, SV3D_u, SV3D_p, SD3, StableAudio, AuraFlow, PixArtAlpha, PixArtSigma, HunyuanDiT, HunyuanDiT1, FluxInpaint, Flux, FluxSchnell, GenmoMochi, LTXV, HunyuanImage21Refiner, HunyuanImage21, HunyuanVideoSkyreelsI2V, HunyuanVideoI2V, HunyuanVideo, CosmosT2V, CosmosI2V, CosmosT2IPredict2, CosmosI2VPredict2, Lumina2, WAN22_T2V, WAN21_T2V, WAN21_I2V, WAN21_FunControl2V, WAN21_Vace, WAN21_Camera, WAN22_Camera, WAN22_S2V, Hunyuan3Dv2mini, Hunyuan3Dv2, Hunyuan3Dv2_1, HiDream, Chroma, ACEStep, Omnigen2, QwenImage]
+models = [LotusD, Stable_Zero123, SD15_instructpix2pix, SD15, SD20, SD21UnclipL, SD21UnclipH, SDXL_instructpix2pix, SDXLRefiner, SDXL, SSD1B, KOALA_700M, KOALA_1B, Segmind_Vega, SD_X4Upscaler, Stable_Cascade_C, Stable_Cascade_B, SV3D_u, SV3D_p, SD3, StableAudio, AuraFlow, PixArtAlpha, PixArtSigma, HunyuanDiT, HunyuanDiT1, FluxInpaint, Flux, FluxSchnell, GenmoMochi, LTXV, HunyuanImage21Refiner, HunyuanImage21, HunyuanVideoSkyreelsI2V, HunyuanVideoI2V, HunyuanVideo, CosmosT2V, CosmosI2V, CosmosT2IPredict2, CosmosI2VPredict2, Lumina2, WAN22_T2V, WAN21_T2V, WAN21_I2V, WAN21_FunControl2V, WAN21_Vace, WAN21_Camera, WAN22_Camera, WAN22_S2V, Hunyuan3Dv2mini, Hunyuan3Dv2, Hunyuan3Dv2_1, HiDream, Chroma, ChromaRadiance, ACEStep, Omnigen2, QwenImage]
 
 models += [SVD_img2vid]

comfy_extras/nodes_chroma_radiance.py

@@ -0,0 +1,114 @@
+from typing_extensions import override
+from typing import Callable
+
+import torch
+
+import comfy.model_management
+from comfy_api.latest import ComfyExtension, io
+
+import nodes
+
+class EmptyChromaRadianceLatentImage(io.ComfyNode):
+    @classmethod
+    def define_schema(cls) -> io.Schema:
+        return io.Schema(
+            node_id="EmptyChromaRadianceLatentImage",
+            category="latent/chroma_radiance",
+            inputs=[
+                io.Int.Input(id="width", default=1024, min=16, max=nodes.MAX_RESOLUTION, step=16),
+                io.Int.Input(id="height", default=1024, min=16, max=nodes.MAX_RESOLUTION, step=16),
+                io.Int.Input(id="batch_size", default=1, min=1, max=4096),
+            ],
+            outputs=[io.Latent().Output()],
+        )
+
+    @classmethod
+    def execute(cls, *, width: int, height: int, batch_size: int=1) -> io.NodeOutput:
+        latent = torch.zeros((batch_size, 3, height, width), device=comfy.model_management.intermediate_device())
+        return io.NodeOutput({"samples":latent})
+
+
+class ChromaRadianceOptions(io.ComfyNode):
+    @classmethod
+    def define_schema(cls) -> io.Schema:
+        return io.Schema(
+            node_id="ChromaRadianceOptions",
+            category="model_patches/chroma_radiance",
+            description="Allows setting advanced options for the Chroma Radiance model.",
+            inputs=[
+                io.Model.Input(id="model"),
+                io.Boolean.Input(
+                    id="preserve_wrapper",
+                    default=True,
+                    tooltip="When enabled, will delegate to an existing model function wrapper if it exists. Generally should be left enabled.",
+                ),
+                io.Float.Input(
+                    id="start_sigma",
+                    default=1.0,
+                    min=0.0,
+                    max=1.0,
+                    tooltip="First sigma that these options will be in effect.",
+                ),
+                io.Float.Input(
+                    id="end_sigma",
+                    default=0.0,
+                    min=0.0,
+                    max=1.0,
+                    tooltip="Last sigma that these options will be in effect.",
+                ),
+                io.Int.Input(
+                    id="nerf_tile_size",
+                    default=-1,
+                    min=-1,
+                    tooltip="Allows overriding the default NeRF tile size. -1 means use the default (32). 0 means use non-tiling mode (may require a lot of VRAM).",
+                ),
+            ],
+            outputs=[io.Model.Output()],
+        )
+
+    @classmethod
+    def execute(
+        cls,
+        *,
+        model: io.Model.Type,
+        preserve_wrapper: bool,
+        start_sigma: float,
+        end_sigma: float,
+        nerf_tile_size: int,
+    ) -> io.NodeOutput:
+        radiance_options = {}
+        if nerf_tile_size >= 0:
+            radiance_options["nerf_tile_size"] = nerf_tile_size
+
+        if not radiance_options:
+            return io.NodeOutput(model)
+
+        old_wrapper = model.model_options.get("model_function_wrapper")
+
+        def model_function_wrapper(apply_model: Callable, args: dict) -> torch.Tensor:
+            c = args["c"].copy()
+            sigma = args["timestep"].max().detach().cpu().item()
+            if end_sigma <= sigma <= start_sigma:
+                transformer_options = c.get("transformer_options", {}).copy()
+                transformer_options["chroma_radiance_options"] = radiance_options.copy()
+                c["transformer_options"] = transformer_options
+            if not (preserve_wrapper and old_wrapper):
+                return apply_model(args["input"], args["timestep"], **c)
+            return old_wrapper(apply_model, args | {"c": c})
+
+        model = model.clone()
+        model.set_model_unet_function_wrapper(model_function_wrapper)
+        return io.NodeOutput(model)
+
+
+class ChromaRadianceExtension(ComfyExtension):
+    @override
+    async def get_node_list(self) -> list[type[io.ComfyNode]]:
+        return [
+            EmptyChromaRadianceLatentImage,
+            ChromaRadianceOptions,
+        ]
+
+
+async def comfy_entrypoint() -> ChromaRadianceExtension:
+    return ChromaRadianceExtension()

nodes.py

@@ -730,6 +730,7 @@ class VAELoader:
             vaes.append("taesd3")
         if f1_taesd_dec and f1_taesd_enc:
             vaes.append("taef1")
+        vaes.append("chroma_radiance")
         return vaes
 
     @staticmethod
@@ -772,7 +773,9 @@ class VAELoader:
 
     #TODO: scale factor?
     def load_vae(self, vae_name):
-        if vae_name in ["taesd", "taesdxl", "taesd3", "taef1"]:
+        if vae_name == "chroma_radiance":
+            return (comfy.sd.PixelspaceConversionVAE(),)
+        elif vae_name in ["taesd", "taesdxl", "taesd3", "taef1"]:
             sd = self.load_taesd(vae_name)
         else:
             vae_path = folder_paths.get_full_path_or_raise("vae", vae_name)
@@ -2322,6 +2325,7 @@ async def init_builtin_extra_nodes():
         "nodes_tcfg.py",
         "nodes_context_windows.py",
         "nodes_qwen.py",
+        "nodes_chroma_radiance.py",
         "nodes_model_patch.py",
         "nodes_easycache.py",
         "nodes_audio_encoder.py",