Re-enable computing of scalars on Contours filter.
Re-enable computing of scalars on Contours filter.

This is essential to be able to color contours properly.

Hovden/tomviz,cryos/tomviz,yijiang1/tomviz,thewtex/tomviz,cjh1/tomviz,OpenChemistry/tomviz,yijiang1/tomviz,mathturtle/tomviz,mathturtle/tomviz,cryos/tomviz,cjh1/tomviz,thewtex/tomviz,OpenChemistry/tomviz,thewtex/tomviz,OpenChemistry/tomviz,Hovden/tomviz,mathturtle/tomviz,cjh1/tomviz,cryos/tomviz,OpenChemistry/tomviz