Atom Posted October 29, 2016 Share Posted October 29, 2016 (edited) Hi All, I have a point that is copied to a line that is projected onto a mesh surface. I have an attributeVOP that animates the U coordinate to move the point along the line. I have a polyFrame with non default values to help with the up vector. I also have a Copy that copies my row boat to the point. Most of the time the animation works as expected the boat appears to travel along the curvature of the mesh. At a few points along the path the boat rotation flips around 360 degrees. Does anyone know why this is happening? I'm not sure how to fix that... ap_me_rm_jimi_chest_plate_ripple_102916_1b.hipnc Edited October 30, 2016 by Atom Quote Link to comment Share on other sites More sharing options...
mine Posted October 29, 2016 Share Posted October 29, 2016 I don't know why the float flips around, but you can fix this just creating the up vector before the copy node. I did it and it seems to work as expected Quote Link to comment Share on other sites More sharing options...
Atom Posted October 30, 2016 Author Share Posted October 30, 2016 (edited) But the polyFrame creates an up vector already. Are you saying you are overwriting that existing up vector with a new value? How are you constructing the up vector, with a wrangle..? v@up = set(0,1,0); Edited October 30, 2016 by Atom Quote Link to comment Share on other sites More sharing options...
mawi Posted October 30, 2016 Share Posted October 30, 2016 1 hour ago, Atom said: But the polyFrame creates an up vector already. Are you saying you are overwriting that existing up vector with a new value? How are you constructing the up vector, with a wrangle..? v@up = set(0,1,0); There is no up-vector. You use the primuv vop to fetch N and P, but not up. Quote Link to comment Share on other sites More sharing options...
Atom Posted October 30, 2016 Author Share Posted October 30, 2016 (edited) Ok, so the attributeVOP is discarding/ignoring the up provided by the polyFrame so it needs to be re-established after the VOP to make up for that loss. In this case it looks like the code is... v@up = set(0,-1,0); Thanks for the help! Edited October 30, 2016 by Atom Quote Link to comment Share on other sites More sharing options...
mawi Posted October 30, 2016 Share Posted October 30, 2016 1 hour ago, Atom said: Ok, so the attributeVOP is discarding/ignoring the up provided by the polyFrame so it needs to be re-established after the VOP to make up for that loss. In this case it looks like the code is... v@up = set(0,-1,0); Thanks for the help! The vop is not discarding/ignoring anything in the first input, but your up vector is on the curve in the second. You need to fetch it, just like you have done with P and N inside that vop. Quote Link to comment Share on other sites More sharing options...
Atom Posted October 30, 2016 Author Share Posted October 30, 2016 Ah, so attributes on other input sockets are not implicitly inherited. Got it. Quote Link to comment Share on other sites More sharing options...
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