Preamble.... Ever tried to make the land around your building pad flow gently down to harmoniously meet the correct level only to find jagged surfaces and 'zigzagging'. Well now your woes are over.
1. In a plan view, mark out the area you wish to be flat (or evenly sloped with a minor tweak to the method) with model lines, ensure that they are a continuous chain for speed sake.
2. Use the 'split surface' tool and 'tab highlight chain' with the 'pick' tool and click to select the pad outline and 'finish' to split off the pad.
3. Use the 'split surface' tool on the remaining (outside the pad) surface and 'tab highlight chain' with the 'pick' tool with an offset of your desired batter distance (if it is steep terrain and you require a minimum grade you may want to manually draw these lines) and click to select the pad outline and finish to split off the batter.
You should now have 3 different surfaces, the building platform, the batter and the remainder...
4. Edit the building pad portion of your surface and delete any internal points then finish. Do the same with the batter portion being diligent to not delete ANY of the edge points.
I have tried for a few years placing points manually (0mm relative to surface) to make this work with mixed results. If you use the split surface tool, points are generated along the split lines based on the triangulation edges that define the surface and generate contours
5. Use the 'merge surfaces' tool to join the building pad and the batter sections of topography together. Ensure that the 'remove points on common edges' is unchecked.
6. Edit the newly joined toposurface. You will find a trail of points along the line of the recent join. select all these points and change their height to the desired level. If you require a slope to your pad, switch to the predefined elevation/section and 'rotate' the points to your desired slope, before losing selection. Finish the surface.
7. Use 'merge surfaces' to combine the two remaining surfaces, again ensure that the 'remove points on common edges' is unchecked.. The result is an accurate batter between the original topography and the desired pad.
If you create a building pad with the 'building pad' tool and cut sections, you will find that the surface is pretty damned accurate, almost indistinguishable in 3D
Thanks to Tim West, who wrote this tutorial on the Revitforum, and allowed us to repost it here.