@Drigax and @Barak_Moshe, I’m pretty sure the zero scale on a mesh issue is due to the bounding box issues that come with it. Here is a glb that has a simple sphere mesh and a single joint that starts at scale 0 and scales up after 100 frames. If you drop this into the sandbox, the bounding box is derived from the zero scale mesh and the camera in the sandbox is positioned based on filling the viewport with the bounding box.
If you use the attached mesh below in the sandbox you will see that the camera is too close to the model and when it animates, the camera ends up inside the mesh. I don’t know the entire history here, but my guess is that when remix3d was a focus here we needed to make sure that their viewer would never have the camera end up inside the mesh. The viewer for remix3D was built on Babylon and was very similar to the sandbox.
For the issue at hand, if we are only worried about exporting meshes that are used in engine where the camera is set by code and not automated like in the sandbox, then we should be able to export at any frame. If we worry about breaking the sandbox, we should potentially look at how we can still support the automatic placement of the camera based on the unscaled mesh, but still export at the desired frame.
zeroScaleJoint.zip (13.9 KB)
For some context on exporting from the bind pose, I will say that exporting from a frame different than the bind pose is not uncommon. I used to place my bind pose at a frame like -10 and then start my animation clips at frame 1 and export from frame 1. Most of the time, we don’t care about having the bind pose on a rig going into a game engine as they are likely a T-pose on a model like a character which has little use in engine. Keeping them in the negative frame range meant your DCC file always had access to it, but you could export clean files for each animation clip.
Plus, if your pipeline created one animation file for each clip, including the bind pose in each one was a waste of file size. We are always concerned with load time so that extra data in bind pose over and over adds up. And many studios would use one file per animation clip so that multiple animators could work on the same character at once and not stomp each other’s changes. So I don’t think we can guarantee that every model will be exported from their bind pose particularly if you want multiple files for animations.