Grading spiking to nothing

[EarthShifter88]

Hi,

I have created a proposed surface and would like to do a 1 in 3 grade from my feature line to my existing surface. the problem i'm having is that i keep getting spike to various levels where there is not information. I have never had this problem before and its really getting on my nerves now! does anyone have any solutions/advice?

Cheers

Will

[remi678731]

HI
is it projecting off the edge of your existing surface ?
it should project to zero unless from some reason it thinks there is something there.
Just out of curiosity select both surfaces, right click, at the bottom of the menu select object veiwer roll them in 3d, if the view is still set to wire frame change it to conceptual in the upper right hand corner of the viewer