kylemcdonald / ofxbvh Goto Github PK

View Code? Open in Web Editor NEW

13.0 13.0 6.0 408 KB

openFrameworks addon for parsing, rendering, manipulating and saving BVH files.

License: MIT License

C++ 91.00% Makefile 0.05% C 8.95%

ofxbvh's People

Contributors

Stargazers

Watchers

Forkers

2bbb amytraylor yazici daitomanabe cualquiercosa327 hanasaan

ofxbvh's Issues

Cropping/splitting motion data

In some cases it may be helpful to save new files with a "cropped" selection of the motion data. This can probably be done in external GUI editors for BVH as well, so it's not a high priority.

convert 6-channel to 3-channel

make example of rigging ofxFBX from ofxBvh

it should "just work" depending on how you rigged your FBX model, but there might be orientation problems and it would be good to have an example of how to fix that.

average the frame duration for playback

playback often drops frames because OF alternates between short and long frames. if we instead use an average of the last few frames to predict the "real" frame time, then playback may be more accurate.

use ofxBvhJoint::raw without ofxBvhJoint::channels

this could simplify some of the code, writing ofxBvhJoint::channels as ofxBvhJoint::raw.size()

move exporting functions inside ofxBvh

Bulk data lookup

vector<vector<glm::mat4>> ofxBvh::getLocalMats();
vector<vector<glm::mat4>> ofxBvh::getGlobalMats();

possibly also the transposed version:

vector<vector<glm::mat4>> ofxBvh::getLocalMatsByJoint();
vector<vector<glm::mat4>> ofxBvh::getGlobalMatsByJoint();

getJoint(unsigned int i) and getJoint(string name) should be O(1)

Cache the index and name mappings when building the hierarchy.

Separate reading/writing motion from reading/writing matrices

vector<double> ofxBvhJoint::raw;
void ofxBvhJoint::updateMotion(vector<double>::const_iterator& frame); // write to raw
void ofxBvhJoint::updateMatrices(glm::mat4 global); // write to localMat and globalMat
void ofxBvhJoint::readMotion(); // read from raw to vector<double>
void ofxBvhJoint::readMatrices(); // read from localMat to raw

Rendering is not correct

If you watch a BVH file play back, the feet do not stay on the floor.

Things that I tried to change:

x/y/z positions are signed correctly
axes for rotation are signed correctly
rotation order seems correct
changing preMult seems correct

One possible explanation is that the way OF handles the transformations used for rendering has changed from the version of OF that ofxBvh was initially written for. In 2012 this would have been 007 or 0071.

https://github.com/perfume-dev/example-openFrameworks

https://github.com/openframeworks/openFrameworks/tree/0071

ofxBvh::clearFrames and ofxBvh::addFrame

Euler angle compile issue

I've found that I need to add this #include to get ofxBvh to compile (OF 0.11) -- otherwise there's an error No member named 'eulerAngleX' in namespace 'glm'

#include "ofxBvh.h"
#include "ofMain.h"
#include "euler.h"
#include <glm/gtx/euler_angles.hpp>

using namespace std;

ofxBvh should play automatically after loading

Downsampling of motion data

For machine learning it might be helpful to downsample data: for example, from 120Hz to 40Hz. To downsample correctly requires running a low pass filter, which is not trivial for the rotation data.