art3mis Posted August 12, 2017 Share Posted August 12, 2017 Trying to create a new Vector attribute from normals but keep getting an error "Unable to evaluate expression..." I can't see anything wrong...can anyone help? Quote Link to comment Share on other sites More sharing options...
Sepu Posted August 12, 2017 Share Posted August 12, 2017 (edited) the last 0 might be your issue, or it might be in the transform if you are applying something to it Edited August 12, 2017 by Sepu Quote Link to comment Share on other sites More sharing options...
Yon Posted August 12, 2017 Share Posted August 12, 2017 If I understand correctly that you are just trying to make a new vector attribute that is your normals just wrangle v@dir = @N; maybe sharing the rest of error code may give us a better idea Quote Link to comment Share on other sites More sharing options...
c0y Posted August 12, 2017 Share Posted August 12, 2017 try @N.x, @N.y, @N.z Quote Link to comment Share on other sites More sharing options...
art3mis Posted August 12, 2017 Author Share Posted August 12, 2017 Thanks, missed that memo...does @N.x now replace $NX ? Anyways am following this tutorial, starting exactly at around 5:30(screenshot attached). The only way I can make the error go away is if I enable the Add SOP and change my class from Point to Vertex in attribute create, which has me puzzled since in my Geo Spreadsheet if I enable Vertices I see nothing in my spreadsheet. Missing something very fundamental! I think the error may be happening 'upstream' in my Point VOP and I'm not correctly generating normals since if I select the Transform SOP and the Attributes drop down, I see nothing though in the tutorial there are both Point and Normal attributes. I've attached my .hip in progress...if anyone could have a look and tell me wtf I am doing wrong would be GREATLY appreciated! edge_displacement_shader_vimeo_5:32.hiplc Quote Link to comment Share on other sites More sharing options...
c0y Posted August 12, 2017 Share Posted August 12, 2017 well it seems to be a bug, but when I create a new attribcreate with @N.x, @N.y and @N.z it works... try delete your node and create a new one. If the error is still there, well, just put it in a point wrangle as Yon said : v@dir = @N; Quote Link to comment Share on other sites More sharing options...
Noobini Posted August 12, 2017 Share Posted August 12, 2017 not bug...you just need eagle eyes... look at next to the gear icon...it's got 'funny' colors.... click on it and change it back (from python) to Hscript Now $NX/Y/Z will work (if you already have something in the fields and after you've changed it back to hscript and still didn't work...just 'delete' all channels and retype in $NX/Y/Z) Quote Link to comment Share on other sites More sharing options...
lavitz01 Posted August 13, 2017 Share Posted August 13, 2017 As Noobini said, N.x is for python scripting and NX is hscript. It all just depends on what coding you are working with. your attributecreate is set to python and not hscript. Quote Link to comment Share on other sites More sharing options...
art3mis Posted August 15, 2017 Author Share Posted August 15, 2017 Thanks..clearer now. Quote Link to comment Share on other sites More sharing options...
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