Terrain node popping

stodge · Post by **stodge** » Tue Jun 14, 2005 11:23 pm

In the example, there's quite a bit of popping in and out as I move around the tile. Is this a feature of the particular algorithm in use?

Spintz · Post by **Spintz** » Wed Jun 15, 2005 1:20 am

Yes, there are ways to help with this "popping" effect. I've yet to implement those features into the terrain node, have had no time to work on it as of late. There are many features for the terrain which can greatly improve the look and performance of the terrain node, time is just not available for me at the moment to work on it!

The term for this is called geomorphing, where when vertices change, they "animate" smoothly to their new position instead of jumping to the new position, which is what causes the popping effect.

soconne · Post by **soconne** » Wed Jun 15, 2005 7:13 pm

Well the popping is not really causes by vertices jumping to a new position, its caused by vertices being "taken out". That's what causes the popping. In order to reduce the effect, you would need to base the decision of which LOD to use for a given patch based on a screen space error formula.

Spintz · Post by **Spintz** » Thu Jun 16, 2005 3:36 pm

Yeah soconne, both of the problems we described are causes of the problem. They both need to be fixed in the current TerrainSceneNode, which I will have much more time for come mid July!! I swear it!!!

Mike · Post by **Mike** » Wed Jun 22, 2005 1:45 pm

Mid-July? Oh no!!!

Guest · Post by **Guest** » Wed Jun 22, 2005 2:40 pm

Never mind - better in July than never

. In current state I'll not use terrain node, because poping is very irritating.

Spintz · Post by **Spintz** » Sat Jun 25, 2005 12:33 pm

Popping really isn't that bad. I've been playing SWG(Star Wars Galaxies) again lately, and the graphics are amazing and the terrain pops like crazy. If you build your world with many interesting aspects, the popping will become less bothersome. Still, I'm going to fix it, eventually...

Mike · Post by **Mike** » Sun Jun 26, 2005 1:53 am

I know and I appreciate it!

Guest · Post by **Guest** » Sun Jun 26, 2005 9:12 am

In space shooters maybe. But in other cases - this is a big disadvantage

So, must any option to avoid this defect.

Spintz · Post by **Spintz** » Mon Jun 27, 2005 5:35 am

SWG isn't just a space shooter. It has many vast worlds.

The thing is, to implement geomorphing, the memory used by the terrian node is going to basically double. I'll need to maintain the original data, with where the terrain should be, and also maintain a copy of that original data, which will be the data that the node is actually rendered from. When a change in the LOD occurs, I'll need to "animate" the Y values for a specific patch from the point where they were to the point where they should end up. I guess I can save on some memory, by just mainting a copy of the Y values of the terrain in an array.

It's really not that hard to implement I guess, it's only really noticeable when you have large height deltas on your terrain. I will implement it, hopefully in about a month or so, when I have time...