Search the Community
Showing results for tags 'transformation'.
Found 4 results
jdiazsaezwd posted a topic in Animation & RiggingHello! I have this two models, one of them is an animated mixamo fbx of a character doing a spin-attack with a sword, and the other is a katana, the mixamo model doesn't have the sword, just the hand open like holding something. I isolated some points on the hand, got the centroid and created a point there, subtracted the position of two points in the palm and the transfered that vector as a normal to the central points where the sword will be, so its aligned to the hand, kind of. This worked for the first frame of the animation but get it comes to the spin the sowrd just keeps the same angle as in the first frame, the long of the sword is correctly oriented but the blade-side of the sword doesn't follow correctly the orientation of the hand. I'm still learning houdini and I for sure missing something and I don't know how to really look up for this anywhere else. Thanks. Here are some snaps: https://gyazo.com/f6dac5288ed223ac63a6ccea8b69fce5 https://gyazo.com/018df6bf2b990d3a9cd2cb8f2b0aff6b https://gyazo.com/0e6803c89574a2899cc7c4ecf005e8fa https://gyazo.com/1f886158016b065d9fca1400ffa4e380
Hello every one, I've been studying some linear algebra to better understand this amazing piece of software called Houdini. I came across some problems and after some RnD I've put together an example scene that I hope can be usefull for every one struggling with matrices and other related concepts. I feel the need to share this, because most of the tutorials I've seen on this subject end up using quaternions for the transformations, and I've put up a Matrix only approach. Do remember that the "correct" approach in this cases is the quaternion one. If any one is kind enough to convert this scene into a .hipnc and re-share it, I'd be grateful. At the moment I don't have time to do it myself. Cheers! Matrix_Transform.hip
Lately I have been trying to wrap my head around transforming point positions with the use of matrices in VOPs. To do that, I tried the following: Lets assume I have 3 points with their position vectors A, B and C which come from an alembic and are constantly changing values. I use a time shift and set it to $F + 1, and extract the same points position vectors, which are now called D, E, F. Then I set A,B and C into a 3x3 matrix, transposing it (to get the vectors in columns instead of rows) and do the same with D, E, F. After all this, I multiplied the inverse of the matrix containing ABC with the one containing DEF (this was not inverted). The resulting matrix was multiplied with new Position inputs, but the resulting transformations didn't match the original ones... What am I doing wrong? Thank you.