- October 26, 2009 at 10:35 pm #29959
Has anybody used FreeWorld3D (FreeWorld3D.org)?
It is a program with potential. Anyway the author uses a “cursor” that rolls over the terrain as you move it. The cursor is comprised of two circles, an inner-outer pair. The two circles follow the contour of the terrain pretty good.
I was wondering if anybody could tell me how the author accomplished this?
I wanted to include an image here, but I don’t know how (sorry).
Thanks in advance for your help,
JerryOctober 27, 2009 at 5:54 am #33473
There are many ways to do it … of the top of my head one would be to use projective texture mapping and another to have a hovering subdivided quad, manually updated on each frame to follow the ground shape.October 27, 2009 at 4:53 pm #33474
I thought about the texture approach too, but the “cursor” does not look like one.
And the “hovering quad” is basically the strategy I am employing now. However, sometimes the terrain is above the item I am rendering.
Basically I am looking for a surefire way of rendering vector data over topology. From what I observed with the “cursor” it seems to match exactly.October 27, 2009 at 5:28 pm #33475October 27, 2009 at 5:35 pm #33476
And it does look like subdivided lines. Place the cursor farther back in that image where the slope is really varied, and it hugs the terrain pretty good.
When I was looking at it, the divisions are not necessarily are 1-to-1 match. Yet the cursor is never hidden by the terrain.