Enhance Footage with SwitchLight AI and Nuke
Table of Contents:
- Introduction
- Using Switch Light AI Tool to Relight Foreground Elements
2.1 Importing the Sequence to Nuke
2.2 Customizing the Keyframes
2.3 Writing Keyframes as a PNG Sequence
2.4 Selecting Frames for AI Processing
- Relighting with Switch Light AI
3.1 Accessing Switch Light Online Platform
3.2 Choosing HDRIs for Relighting
3.3 Relighting with HDRs
3.3.1 Adjusting the HDR Rotation and Strength
3.4 Applying Relighting to All Frames
3.5 Advanced Options for Better Edges
- Downloading the Relit Foreground Passes
- Training the Copycat Node in Nuke
5.1 Setting Up Input and Output Data
5.2 Configuring Copycat Node Training
- Applying the Trained Data to the Sequence
- Background Setup and Final Touches
7.1 Inpainting the Background
7.2 Deflickering the Sequence
7.3 Pre-molding and Blending the Foreground and Background
- Conclusion
- FAQ
Using Switch Light AI Tool to Relight Foreground Elements
Introduction:
In this tutorial, I will guide you on how to use the Switch Light AI tool to relight foreground elements. We will explore how to bring the relit keyframes into Nuke using the Copycat node to generate datasets. Additionally, I will provide tips on selecting frames for AI processing and optimizing the relighting results. Let's dive in!
1. Importing the Sequence to Nuke
To begin, import your sequence into Nuke. Ensure that you have a Nuke non-commercial version, as it includes the Copycat node for machine learning purposes. Perform any necessary adjustments, such as customizing the keyframes and applying edge expansion to eliminate unwanted artifacts.
2. Writing Keyframes as a PNG Sequence
Next, write the keyframes as a PNG sequence with alpha. This will ensure that all frames are saved with transparency, ready for further processing.
3. Selecting Frames for AI Processing
When selecting frames to feed into the AI, choose ones that showcase extreme actions. These frames should provide sufficient information for the AI to generate accurate relighting. Pick frames with unique elements, such as hands in front of the chest or eyes, to maximize effectiveness.
4. Accessing Switch Light Online Platform
Open the Switch Light online platform, where you can find a variety of HDRIs to choose from for relighting your foreground elements. Sign up for credits to access more features and experiment with the tool.
5. Choosing HDRIs for Relighting
Navigate to the "Create" tab in the online platform. Here, you have two options: "Relight with HDR" and "Relight with Portrait." For this tutorial, we will focus on relighting with HDR. Select the desired HDR image from the platform's presets.
6. Relighting with HDRs
In the simple and intuitive interface, upload your own HDRIs or choose one from the presets. Apply the selected HDR to your previously chosen frames and adjust the strength to achieve the desired relighting effect. You can preview the impact of the HDR rotation and intensity on the sphere provided in the interface.
7. Applying Relighting to All Frames
Once you are satisfied with the relighting on a particular frame, apply it to all the selected frames simultaneously. Ensure that the edges are well-defined and use the "Advanced Options" to enable alpha usage for better edge preservation.
8. Downloading the Relit Foreground Passes
After the relighting process is complete, download all the relit foreground passes. These include passes for albedo, normal, and the composite with the relighting applied. These passes will be used in the subsequent steps.
9. Training the Copycat Node in Nuke
Bring the original keyframes and the relit foreground passes into Nuke. Configure the global frame range to match the number of frames in your sequence. Use the Copycat node to train the data sets, allowing it to simulate the relighting based on the provided inputs.
10. Applying the Trained Data to the Sequence
Create an inference node in the Copycat node using the trained data. Connect it to the sequence, and you will see the relit foreground being applied to the entire sequence.
11. Background Setup and Final Touches
To complete the composite, we need to address the background. Use the relit composite pass from Switch Light to punch a hole in the background. Employ inpainting and paint-out techniques to seamlessly blend the background. Apply deflickering to reduce any remaining flickering issues. Finally, perform pre-molding and blend the foreground and background using appropriate nodes in Nuke.
12. Conclusion
Switch Light AI, combined with Nuke's powerful compositing capabilities, offers a remarkable solution for relighting foreground elements. By following the steps outlined in this tutorial, you can effectively utilize machine learning to enhance the visual impact of your composites.
FAQ
Q: Can I use the Switch Light AI tool with any version of Nuke?
A: No, Switch Light AI tools are available in the Nuke non-commercial version. Make sure you have the appropriate software to access these features.
Q: How many keyframes should I select for AI processing?
A: It is recommended to choose around 8 keyframes with extreme actions and distinct elements to provide sufficient information for accurate relighting.
Q: Can I use my own HDRIs for relighting?
A: Yes, the Switch Light AI tool allows you to upload your own HDRIs or choose from the presets available on the online platform.
Q: How can I improve the edge preservation during the relighting process?
A: Enable alpha usage in the advanced options to ensure better edge preservation and control over the relighting effect.
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