Discontinuities for cliffs etc.

I recently discarded the graphics engine of our Game Project, using Ogre now. The PLSM did a great job in helping us getting up to speed. (Thanks)

However, there is one limitiation I am not so fond of: its strictly using heighfields. The previous engine used a mixture of heightfield, but with added discontinuities. The procedure was approximately like this:

- a B-Spline curve is projected onto the terrain where a cliff should be
- the terrain is lowered on one side, raised on the other
- the curve is rasterized to a special texture (1bpp) with the same resolution as the heightfield. During geometry generation, this part is left away. So wherever there is a curve, no terrain is drawn.
- the gaps created this way are filled with procedurally generated geometry (basically an extrusion of the curve against some profile.

My question is: I am currently thinking if I should implement a custom modification of PLSM or go into the effort of providing this to everybody. Its clear making a release will be more work. So I would like to know if anybody would be interested in this feature.

This has been bandied about quite a bit in the Ogre community. I think a lot of people settled on the idea of flagging areas in the terrain as gaps, and having the scene manager leaving them blank. The gaps just get filled in with placed geometry. So, you'd model your cliff, then stick it on the terrain where it belongs. I'm not sure if there are people working on this already. You might want to stop by and see the PLSM3 discussions, since Tuan has started planning and/or implementing his next iteration of PLSM.

Well, playing devils advocate, matching said cliff to surrounding tiles of terrain will be extremely tedious and time consuming, imo. Just imagining doing it that way makes me want to cringe. I wouldn't want to use more precious time from my limited modeling team just making rocks.

I know that is the "accepted" way of doing it, but it would make more sense in my eyes to just place the mesh on top of the terrain as is. Yes, there are wasted polys there, but at least you do not have to create a mesh that perfectly lines up to the surrounding 8 tiles. Its late and I have not put much thought into this yet, so bonk me if I am way off base here.

P.S. My team would be interested in other options/addition to PLSM. No offense intended toward Tuan and all his excellent work.

morfiel,

Any additions the the paging landscape scene manager, including cliffs, are definitely desired by the community.

I'm sure I'd use them, and so would others.

So I would like to know if anybody would be interested in this feature.

That would be awesome... i'd certainly be interested in this concept.