Export to Nuke with Anamorphic Lens Distortion

Runs through the many new features of the Nuke exporter in SynthEyes 2304, including distortion export to Nuke Lens Distortion nodes (not STmaps) using overscan rendering if the Lens Workflow script has not been run; supporting both 1‐ and 2‐pass workflows if it has. Other features include projection screens, auto‐run, paste‐to‐clipboard, and New 3‐D support.

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Hi, this is Russ Andersson. Today I'm going to talk about the updated Nuke exporter in SynthEyes 2304. It's got some great improvements to take advantage of SynthEyes's new lens models, many of which can be exported to Nuke without using STMaps and even without the Lens Workflow script, taking advantage of overscan rendering in Nuke. Let's get right to it, with our first export. We're using the final result from the Anamorphic Lidar tutorial as our starting point. Your first reaction is probably that this is quite a lot, with links going back and forth. There are two main paths here, one for undistortion on the left, the other for REdistortion on the right. Here's our primary output, corresponding to Lens Workflow #2, where we composite redistorted renders over the original footage. You can see the final merge at bottom right. There are no STmaps here; a Nuke Lens Distortion node is doing most of the work. There are a few additional nodes because it's an anamorphic shot with rotation and vertical scaling. In simpler situations, fewer nodes are generated. Notice that we didn't run the Lens Workflow in SynthEyes. Instead, that effect is being achieved using overscan rendering within Nuke; the overscan replaces the padding. I'll put a Viewer on the renderer, and we can see that. There's quite a bit of overscan; SynthEyes has computed the amount required for this scene. If I drop the overscan to zero, you'll see that part of the image drops out, around the edges there. That's because the distortion makes the image smaller, so we need that overscan to make sure that the image reaches the edge of the frame. So I'll just undo that now, and we're back to the full size render again. You've likely noticed these little green dots; those are renderable tracker markers. They are good for being able to see where the trackers are, in comparison to geometry you are inserting. You can control their size however much you need, but unfortunately when there are this many, almost 1700, they do slow Nuke down a bit, so we will drop them out. Now let's take a look at the scene in the 3-D Viewer. You can see the coordinate axes for the trackers; they are good for parenting things to. They sit in a group; you can pull them out of there as needed. Since there are a lot of them and they clutter up the display; let's disconnect them too. When you export, you can select whether you want to export the renderable marks or the coordinate axes or both or neither of them, depending on what you want to do. Either way, instead of disconnecting those groups, it's a good idea to adjust the trackers' Exportable settings before exporting, so that only a smaller number of interesting trackers are exported. Most of the image is actually the mesh; let's change it to wireframe. As I scrub through the shot, you can see that the incoming image is displayed on a projection screen for faster display in the 3D view. You also have the option to export a plain card that is textured with the undistorted version of the images. The projection screen is set to OFF for renders, so that renders are composited over the original image, not the projection screen. Let's go back to SynthEyes for some more options. You can run the Lens Workflow script before exporting, and the result will be sent to Nuke appropriately. That's especially useful if you use Export Multiple to send the same scene to several applications and want it to be consistent. I'm going to run Lens Workflow #1, which gives the largest possible undistorted image. I'll hit shift-X to export to Nuke again. Here's the result for Workflow #1, where you see an undistortion pipe on the left, with the undistorted result supplied as a background for the renderer. It has a few more nodes to emulate everything the SynthEyes image preprocessor does. The undistorted image is supplied as the background to the scanline render, though you may want to remove that link and set up some more complex compositing. We can go back to SynthEyes, undo workflow #1 and now run workflow #2. One of the reasons these exports run quickly, despite the large mesh, is that the exporter is just telling Nuke to go read the stairway file, rather than exporting a whole new copy. This is controlled by the "Export meshes as OBJ/USD" control; it is set to "All non-imported" at present. If you import a mesh and edit it, you do want SynthEyes to export a new copy. To do that, you can set the control to "All", or remove the import filename from the mesh with the new "Mesh/Remove import filename" script. If you're a little trickier, you can write the modified mesh, and use Synthia to change the import file to the new version. I don't need to do that here, we'll just let the export run. Here's a full lens workflow #2 setup. Again, it's a bit more complex than the no-pass direct export, but this is still good if you want consistency between exports from SynthEyes to different apps. Here in the 3-D view, notice how the projection screen is inset within the camera render frame in workflow #2, rather than relying on the overscan. The "undistortion" path, over here, is largely for verification and optionally for display on a "card" as the background. Let me mention a few other things. You can have SynthEyes put the nodes on the clipboard after writing them; you can then Edit/Paste them directly into an existing comp in Nuke. That can save some time. One word of warning though: copy and paste only after you've opened the scene once! Project settings such as the shot's resolution, frame rate, and length is not pasted, only the nodes. You can also have SynthEyes start Nuke immediately after the export. That will create a new Nuke instance, which can take some time to start up. You'll have to decide whether you want to do that, use the clipboard, or just open the comp as I've done in this tutorial. Oh, one more thing. The exporter supports the beta version of Nuke's "New 3-D" System, which uses the USD file format. In fact, the Nuke exporter already uses USD for the projection screens. The exporter is ready as the "New 3-D" system evolves towards production readiness. I hope you're as excited about all these new capabilities as I am. 2304 is a big step forward not only for SynthEyes, but for bringing a full feature set to the Nuke exporter. And by the way, the Fusion exporter is pretty similar! Thanks for watching and don't forget to hit the Subscribe button.