3D Round Tripping with FBX – Part 1 – Flame 2018.3 Update

3D Round Tripping with FBX – Part 1 – Flame 2018.3 Update


Hi everyone, Grant for the Flame Learning Channel. In the next few videos… You’ll look at the workflow of round tripping 3D geometry… between Autodesk Flame and Autodesk Maya. You are not restricted to using specific 3D applications… But these two applications work well together. So you’ll start off importing 3D geometry into Flame… and making changes. This will be exported to Maya for further refinements… And finally exported back to Flame for final finishing. This is all done with the FBX format… which is accepted by most 3D applications. If you’d like to follow along… ensure you are running the Flame 2018.3 update… As well as Maya 2018.1. The files can be downloaded via the YouTube description… Or alternatively if you are watching the podcast version of this video… Than please type the displayed link in your favourite web browser. Now you’ll be working in a Linear colour space… since there will be 3D objects using physical based materials… and Image based lighting. So when you import the downloaded background… Please ensure you tag it as Scene-Linear Rec709/sRGB. You can set this up on import… or change the clip’s colour management settings in Batch. Please also load the accompanying Batch setup… in order to follow along. So this is a flow-graph using a linear pipeline… and you can see the colour space description under each node. Double-click the Action node for its controls… And switch to a 2-up view with ALT+2. Ensure you are looking at the Action Schematic and Result view. The result view should be viewed through the linear viewing transform. The background image has already been positioned back and scaled in 3D space… to make room for the incoming 3D models. Now the geometry has already been made in Maya… and you’ll start off by importing it as an FBX. Call up the contextual menu in the Action Schematic… And choose import. Navigate the browser to the downloaded FBX… And select it. At the bottom of the browser… Ensure that Auto-Fit in Scene is enabled. This scales the geometry to a usable size within the Action 3D composite. You should not need to touch any of the other default FBX import settings. Click the LOAD button… And Flame will import the file… and construct the geometry in the 3D scene. Panning the schematic… You have a few components to the 3D geometry. There are a few objects with material nodes… And a new camera with a 3D move. Let’s look through the imported camera… to match what was seen in Maya. Double-click the Camera 2 node… And switch the Result camera from DefaultCam… To Camera2. If you scrub the time-bar… You can see a movement that tracks forward to the 3D logo. You’ll change that later… But let’s apply lighting and physical based textures to the 3D scene. Select the Camera2 node again… And call up the contextual menu. Choose ADD Node and select IBL. The IBL node appears… And lights the 3D scene using the background image in the media list. This image is not an HDR image… so the lighting is really not adequate. Switch to the IBL controls… and click the Read File menu. Click LOAD. In the browser, you have a set of HDR images… that are bundled with Flame. You can use your own… But I recommend using the StingraySkyDome… As this is the default HDR image that Maya uses. This will ensure the lighting matches between the applications… And you can change and experiment without any limitations. Load the file and it updates the IBL. It is quite a dark image… So switch to the Controls menu and up the Gain to 400. Now the geometry is being lit by Image-Based Lighting… But the materials don’t react properly… Because they are not currently Physical-Based or PBR materials. You could import OpenEXR textures as PBR materials… and assign them to the models. But this is also a good time to point out the Substance PBR textures… Which are procedural based. There are quite a few bundled with Flame… and there are vast possibilities. So let’s start off by retexturing the blue disc with something more funky. Delete the Material node… And call up the contextual menu over the Geometry node. Choose ADD map… And select SUBSTANCE PBR. In the browser, go into the “Manmade” folder… And choose PLASTIC DOTS. So a cool textured material is added to the geometry… And you can click the substance node… And change its colour to blue. Next, you’ll texture the letters with a metal-type of material. Delete the material node… And select the letter F geometry. As before, go to the contextual menu… And add a Substance PBR to the node. In the browser, navigate to the “Metal” folder… And choose METAL_STEEL_BUMPED. Now to apply that look to the remaining letters… You need to connect up the material and shader node. Grab the material node and hold SHIFT+ALT. This keyboard shortcut will allow you to reverse parent one node to many nodes in the schematic. The arrows much point to the material node. As for the shader node… The blue connection is a lighting connection… And this needs to be connected as well. Hold SHIFT+L for a lighting link… And touch the shader node on the two geometry nodes. This will apply the “steel bumped” material to all the letters. Scrubbing the time-bar… All the PBR materials are reacting with the IBL map on the current camera. Now let’s say for argument sake… A few issues have come light. The producer wants the camera to pull out… instead of tracking towards the logo. The can easily be done in Flame. Locate and select the Camera node in the Action schematic. Calling up the controls and scrubbing the time-bar… You can see the animation on Z-position of the imported camera. To quickly reverse the animation… Hold SHIFT and double-click the channel to bring it up in the channel editor. Switch to the viewer menu… And to the right of the channel editor… Click the REVERSE math operation. This switches the curve… And scrubbing the time-bar shows the result. Exit the channel editor and press ALT+2 for the 2-up view. This is one of many examples of tweaking imported geometry in Flame. However, there are instances where you would need to go back to your 3D application. For example, zoom into the blue disc. This model has a low polygon count… which makes it quite harsh. This needs to be smoothed with more polygons. Secondly, the dots on the texture need to be round and not oval… So there is a problem with the model’s UV map. You could get around these issues with the Flame’s tools… But if you have the time to go back to 3D to fix this… You could save a lot of time trying to find workarounds. Finally, I’d like those Octagons to be circles instead. That’s something you couldn’t adjust in Flame without importing a new model. So let’s take this entire scene… And send it back to Autodesk Maya using the FBX format. Call up the contextual menu… And choose EXPORT. Flame is set to export a FBX file… And it can be all the Supported Objects in the 3D composite… Or a selection of supported objects. So very importantly for a FBX export… Any geometry created in Flame cannot be exported. This includes 3D text, 3D shapes, particles etc. Any externally imported geometry should be fine. Any image objects with media… Will only export the first frame as a reference. You use this for positioning and orientating in Maya. Finally, object animation, cameras and lights are also supported. Now one very important setting is the FBX version. You need to ensure that you choose the right FBX version supported by your 3D application… Otherwise this won’t work. Now give your file a name… And export to your designated folder. In the next video… You’ll import this FBX into Maya 2018.1… And use the same dataset to fix issues… And refine the geometry further. Please move onto the next video. Don’t forget to also check out the other workflows, features… and enhancements to the Flame 2018.3 update. Comments, feedback and suggestions are always welcome and appreciated. Thank you for watching and please subscribe to
the Flame Learning Channel for future videos.

Leave a Reply

Your email address will not be published. Required fields are marked *