Canyon topography 2....

thingiverse

Creating a seamless transition from a 3D model's heightmap to a perfectly aligned, planar ground plane without using a support mesh can be achieved. In Blender, activate the 'Shift + E' key to enable Edge Split Mode and carefully separate your heightmapped mesh from any extruded topological anomalies while keeping the edges smooth. Once the base has been refined and clean, merge all loose faces at once, using the Knife tool ('Ctrl + R'), followed by selecting only isolated faces in Isolate Selected mode (Ctrl + Tab to select only faces that are completely detached from other surfaces). When everything is neatly separated, simply go into Edit Mode (Tab key), then right-click any area outside the base to create a plane as the final component. Blend this newly formed flat element seamlessly onto your desired base plane, which has just been established. This procedure ensures an efficient conversion without manual construction.