![]() ![]() The converted files are located at!LINK! – !/LINK!.Īdvanced Computing Center for the Arts and Design (ACCAD): Hosted at the Ohio State University, this is another great source of free mocap files. Hahne at!LINK! – converted the CMU files to BVH. However, the mocap tool can only read BVH files, so none of these files can be used directly. CMU hosts mocap files in three formats: tvd, c3d and amc. Here are some sites I found useful.ĬMU Graphics Lab Motion Capture Database: Hosted at Carnegie-Mellon University, this is a huge library of mocap files which can be downloaded for free. BVH files can be bought from many commercial sources, but a large range of mocap files are also available for free download. MakeHuman’s mocap tool can only deal with files in Biovision BVH format. There are several different formats that mocap files can be stored in. If this should happen, see!LINK! – Errors and Corrective Actions!/LINK!. The process may even fail completely, usually because MakeWalk failed to automatically identify the bones of a complex rig. Retargeting is a rather involved subject, and it can sometimes result in poor motion. If so, a bone map must be defined manually, see – ]. It is often possible to use MakeWalk with other complex rig, but in that case the automatic bone identification may fail. There is also built-in support for some more complex rigs: the MHX advanced rig from MakeHuman, the MHX rig from MakeHuman and Rigify. MakeWalk works with most straightforward biped rigs with FK arms and legs, such as the Rigify meta-rig. bvh file, but inserted by MakeWalk to calibrate the source armature (defined by the bvh file) and the target armature (the selected armature in the viewport) against each other. It is a cartwheel animation.Īfter a short wait, the armature is doing gymnastics.Īt frame 0 of the animation the armature has been placed in T-pose. We choose the file 90_04.bvh from the CMU database. Select the armature and press the Load And Retarget button. The MakeWalk panels appear in the tool shelf whenever an armature is the active object. In this way we can transfer animations from CMU to the MHX rig, despite the fact that the rest poses are very different. In the rest of the animation, bones in the target armature copy the global rotations of the source armature, apart from differences present in the T-poses. To calibrate the source and target armature against each other, MalkWalk introduces extra keyframes at frame 0, where both armatures are posed in T-pose. If we instead keep the rotation offset from the rest poses, the target pose becomes much better, as shown below. If we insisted that the root bone in the MHX rig would point in the same direction as in the CMU rig, the retargeting would not be very successful, as shown in the figure above. in the CMU armature rest pose the pelvis points forward-down, and in the MHX rig it points straight up. In particular, the root or pelvis bone may point in entirely different directions in different armatures. We do not always want the source and target bones to have identical orientation. Unfortunately, things are a little more complicated. This will ensure that the source bone and the target bone will have the same global orientation. The retargeting process thus consists of making two coordinate transformations: Once the global transformation matrix is known, we can reexpress it in the target bone’s local coordinate system. The local X rotation corresponds to a global Y rotation, and by a different angle. To retarget the pose, we therefore reexpress the transformation in the global coordinate system, as shown below. This is not very useful if the target armature has a diffent rest pose. Since the parent’s local Y points along its axis and its local Z points up, the child bone is rotated around the local X axis. The picture above shows a transformation in the local coordinate system. ![]() If the rest poses of the source and target armatures differ, the source F-curves can not be used directly by the target armature. The motion of each bone is specified in local coordinates, relative to the parent and the bone’s own rest pose. ![]() However, it is not straightforward to assign the source action to the target rig, even if the bones have identical names. from a BVH file) to a given target armature (e.g. The goal of retargeting is to transfer a motion from a source armature (e.g. MakeWalk is a Blender add-on for retargeting mocap data (.bvh files) to a given armature. The MakeWalk tool is now found as a tab on the T-side-panel in Blender.Reference to armatures in older version of MakeHuman.Most of the fundamental information is quite usable, nevertheless. There is a wealth of important information in this document, but some of the detail is badly out of date. ![]()
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