LOD 'Pop-In' help

Blitz3D Forums/Blitz3D Programming/LOD 'Pop-In' help

CodeOrc(Posted 2004) [#1]
Hi All,

I have been playing with the "height-map" ability in B3D for making large world Terrains.

How do you keep the 'Pop-In' from 'Popping'? What I mean is, once I have set my detail=2500, and then I put a building on the 'new mesh' / 'terrain', as you walk past it you see the 'terrain detail' change and the mesh crawls up or down the wall.

How do I keep me mesh/terrain 'as is', to go without change? I have been working on this for the last 10 hours and cannot find the answer.

I hope I explained my problem correctly, please help this troubled newbie :)


Matty(Posted 2004) [#2]
I do not think there is a way to turn off the Level of Detail property of a blitz terrain. Some of your alternatives would be to use a static mesh of the terrain which does not change level of detail. Another alternative is to use a separate static mesh for the area near the building as the ground beneath it and to lower the terrain's height.

For example - if your building was on a cliff side then you could model the cliff in a modeling program and place the building on the cliff model and place the cliff model on the terrain.

Hope that helps.


Ross C(Posted 2004) [#3]
Well, you can turn on terrain morphing.

http://www.blitzbasic.com/b3ddocs/command.php?name=TerrainDetail&ref=3d_a-z

enable it via the terrain detail command, by using the true flag.

You can also scale the terrain up, or your player down, so not as much of the terrain is showing, maybe use fogging and a closer camera range. Trouble with switching off terrain LOD (if it existed) would be, the whole terrain woul be made from 2500 triangles, which would be rubbish.

They way it works, is, the terrain closer to the camera is detailed, the further away the terrain gets, the less and less detailed it gets.

Now, you can get around it, by either using a higher terrain detail value (slower), or reducing your camera range and maybe putting some fog in, to cover up the short camera range. You really got to much about with it, to get it good.

You can also try blurring the heightmap image more, in a modelling program, to reduce the popping effect.


CodeOrc(Posted 2004) [#4]
Thanks for the posts.

@Matty
I have already begun what your suggesting. I figured if I have some parts of my terrain static, it's still easier on the video card than having 'all' of it static. The tricky part becomes placing my 'static' terrain meshes and buildings in the right place.

@Ross C
I have done the true flag, added fog, shortened cam range, and held a prayer session over my comp. The issue is it happens even when I am within a few feet of my building/objects. I tried the higher terrain detail and it was ok until I tested it on my other 3 comps, then they began to choke a bit as they are of less power then my dev comp.

I will do mix of terrain height-mapping and static meshes and when I get to a comfortable solution, I will post a screenshot and get everyone's opinion.

I don't post to the forums much, but when I do, I really appreciate the help and courtisy(spelling?) of the people who post their ideas and solutions, a big thanks to my fellow B3D'ers.


Shambler(Posted 2004) [#5]
Hmmmm 2500 is maybe a little low, the lower this value the higher the risk of popping.


Ross C(Posted 2004) [#6]
I've always found terrains to be rather slow anyway, because the whole mesh needs to be rebuilt practically every frame.