Struggling with polyline edits

Hi folks,
im struggling with polyline today. I know, i know its the most simple of edits (getting near surface weathering right). I'm an old micromine user and so my brain is trained to do something else. But I need to edit on section for this project and every time i make a change to my interp with a polyline or add a point, the surface dives off!! Very frustrating it wont just edit as per my intent. Any tips.... ?
Thanks team
Cheers, CR


  • RachelMurtagh
    RachelMurtagh Posts: 35 admin
    edited April 2021
    @ChrisRobson it's a bit hard to determine what the cause might be from a still image however, I do notice a 'tangent' in the very back end of the polyline. This is a little green cone and currently it points straight down. There may be others on the polyline but this one I can see and the fact that it's pointing straight down means this little cone could be the cause of the surface diving down. 

    You can click on the tangent and hit the delete key (just make sure you haven't selected the entire line). This should remove the tangent and hopefully your surface will straighten up. 

    These tangents can really handy though because they be used to better direct the surface. The tangents can be manipulated by adjusting the scene view - using the mouse to rotate the scene; say for example you want the resulting surface to dip at an angle of 15degrees to the north; set the scene up so you are looking in this direction. Now, in the toolbar you can select all parts of the polyline (image 1) and add tangents (image 2). This adds these little green cones to all the nodes of the polyline and actually twists the ribbon of the polyline to reflect the tangents. You can select the tangents one by one and set their direction individually as well. This will have the result in contorting the polyline ribbon as seen in image 3. Equally, the resulting surface will be contorted where the polyline influences that surface. The visualisation of the cones can be enhanced/reduced by using the setting in the shape properties panel on the bottom right hand side (image 4). 

    Image 1:

    Image 2:

    Image 3: 

    Image 4:

    I hope this is the reason your surface is behaving wildly. If not please don't hesitate to reach out to your local support person and request to do a shared session so further investigation can be done. 

    Have a great weekend,
  • ChrisRobson
    @RachelMurtagh - Thankyou very much for your tips and tricks. I think I've managed to get my surfaces right with your help - still a few weird triangles but I can live with that. 
    Cheers, CR