Dahlia, converting between coord-sys is already working, I'm just trying to understand what kind of euler angles used in Blender
I found this: https://github.com/mrdoob/three.js/issues/2803#issuecomment-11599841 According to that Blender uses EXTRINSIC rotations I wanted to be sure that Blender uses EXTRINSIC rotations this is why I asked this question here, Also I found this: https://wiki.blender.org/index.php/User:Aligorith/EulerRotationOrder It seems Blender only uses STATIC rotations in this algorithm ( Ken Shoemake's algorithm ) if that doc is updated. Original algorithm: https://github.com/erich666/GraphicsGems/blob/master/gemsiv/euler_angle/EulerAngles.h Maybe "static axes" in that algorithm corresponds to "extrinsic rotations" and "rotating axes" corresponds to "intrinsic rotations" in this case everything would be clear -R > On March 25, 2018 at 7:36 PM Dahlia Trimble <[email protected] > mailto:[email protected] > wrote: > > > Maybe this might help provide some insight: > https://www.blender.org/forum/viewtopic.php?t=26417 > > On Sun, Mar 25, 2018 at 7:05 AM, Recep Aslantas <[email protected] > mailto:[email protected] > wrote: > > > > Thanks Gaia for reply, > > > > For testing angles; > > > > In Blender I'm adding rotations to a cube with specific euler order > > e.g. > > XYZ, XZY... then, > > I'm exporting it as COLLADA file to see matrix produced with this > > euler > > angles > > > > Then I'm testing it with cglm library to produce same matrix with > > same > > euler angles like this: > > > > mat4 rot; > > glm_euler_xzy((vec3){Xangle, Yangle, Zangle}, rot); > > glm_mat4_print(rot, stderr); > > > > this produces same matrix as Blender. > > > > The problem is that I was thought that I was implemented intrinsic > > (pitch, > > yaw and roll) rotations > > but now I realized that they are extrinsic (elevation, heading and > > bank) > > rotations > > which are reverse order of intrinsic (intrinsic XZY == extrinsic > > YZX) > > > > So before fix that but I wanted to know what convention > > does Blender use, extrinsic or intrinsic rotations? > > Because after changed the orders, the result will not be same :/ > > > > Recently glm added new euler functions: > > https://github.com/g-truc/glm/ > > pull/744 > > My guess is that glm::eulerAngleYZX will not produce same rotation > > matrix > > as Blender > > > > FWIW, I'm using euler angles in AssetKit ( https://github.com/recp/ > > assetkit ) which is COLLADA/glTF importer > > to convert coordinate systems, for instance Z_UP to Y_UP ... > > > > Thanks > > * Recep > > > > > _______________________________________________ > Bf-committers mailing list > [email protected] mailto:[email protected] > https://lists.blender.org/mailman/listinfo/bf-committers > _______________________________________________ Bf-committers mailing list [email protected] https://lists.blender.org/mailman/listinfo/bf-committers
