Houdini 20.5 Nodes TOP nodes

Train OIDN TOP node

Trains an OIDN model using preprocessed training and validation datasets.

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Since 20.5

Overview

This node is a wrapper around the OIDN training script used to train an OIDN denoising filter model on preprocessed training and validation datasets. Generally, this node should be used in conjunction with Preprocess OIDN.

Installation:

The OIDN scripts require an additional installation of torch (PyTorch) to hython.

Firstly, we intitialize the hython environment by navigating to the Houdini installation directory.

Linux

cd /opt/hfsx.x.x

Mac

cd /Applications/Houdini/Houdinix.x.x/Frameworks/Houdini.framework/Resources

Windows

cd "C:\\Program Files\\Side Effects Software\\Houdini x.x.x"

Then we source the houdini_setup script, followed by an installation of torch to hython.

source houdini_setup
hython -m pip install torch

Parameters

Input Features

The set of input features of the dataset to preprocess for training. The following image features are supported:

hdr

color (high dynamic range) with file extension .hdr.exr

ldr

color (low dynamic range) with file extension .ldr.exr

sh1

color (normalized L1 spherical harmonics) with file extensions .sh1x.exr, .sh1y.exr, and .sh1z.exr

alb

albedo with file extension .alb.exr

nrm

shading normal with file extension .nrm.exr

All input features are assumed to be noisy, including the auxilliary features (e.g. albedo, normal). The auxiliary feature images are optional inputs which usually improve denoising quality and preserve more details.

Clean auxilliary features

This parameter should be enabled when the auxiliary images are noise-free, in which case the reference auxiliary features are used in training instead of the various noisy auxiliary images.

Filter

The filter to train. The filters are:

RT

Generic ray tracing denoising filter suitable for denoising images rendered with Monte Carlo ray tracing methods like unidirectional and bidirectional path tracing.

RTLightmap

Variant of RT filter optimized for denoising HDR and normalized directional lightmaps and does not support LDR images.

The choice of filter determines the HDR/LDR transfer function to be used

Preprocessed Dataset

The directory of the preprocessed dataset.

Training Dataset

The name of the training dataset folder.

Validation Dataset

The name of the validation dataset folder.

Results Directory

The directory to output training results.

Result

The desired name for the training result.

Epoch Count

The number of training epochs.

Valid Epochs

The interval at which the model is evaluated with the validation dataset.

Save Epochs

The interval at which model checkpoints are created to save training progress.

Learning Rate

The initial learning rate.

If the default parameter value of -1 is not modified, the initial learning rate used in the one cycle learning rate scheduler is set to 25. Otherwise, the initial learning rate of Max Learning Rate/Initial Learning Rate is used.

Max Learning Rate

The maximum learning rate. If the default parameter value of -1 is not modified, the max learning rate is set to 3.125e-6 * Batch Size.

Learning Rate Warmup

The percentage of the learning rate schedule cycle spent increasing the learning rate (warm-up).

Batch Size

The total batch size of all devices. The batch size should be divisible by the number of devices.

Loader Count

The number of data loader threads per device.

Precision

The precision to perform training with. By default, training is performed with mixed precision (FP16 and FP32), allowing for faster training and less memory usage.

Device

The device (e.g. CPU, GPU) to use for training computations. The options are: cpu, cuda, and mps.

Device ID

The specified device to use if there are multiple devices of the same kind available (e.g. multiple GPUs).

Device Count

The number of devices to use for data-parallel execution for faster performance.

Advanced

These are advanced parameters that provide finer control over the behavior of the training. In general, these parameters should not require modification.

Transfer Function

The HDR/LDR transfer function to be used.

Model

The network model to use. The only option is unet.

Loss Function

The loss function to use.

MSSSIM Weights

The MS-SSIM scale weights.

Tile Size

The size of the cropped image tiles.

Seed

The seed for PyTorch random number generation.

Deterministic

Make computations deterministic, resulting in slower performance.

Exporting

After training has been completed, there is the option to export the results directory to a ZIP file or a training result to the runtime model weights format (.tza).

Epoch Checkpoint

The epoch checkpoint to export.

If the default parameter value of -1 is not modified, then the latest checkpoint is exported. The entered value must be divisible by the model’s checkpoint interval.

Export Directory

The directory to export the model weights or package.

Filename

The filename of the model weights or package.

See also

TOP nodes