Game Algorithms

Re: QuadTerrain LOD: Finished

fearlessdolphin — Tue, 17 Nov 2009 05:09:21 GMT

Can someone please explain, What does it mean to have a static dataset when working with QuadTree Lods and why is this not a limitation in geometry clipmaps?

Re: QuadTerrain LOD: Finished

TnTGaming — Thu, 15 Oct 2009 14:13:27 GMT

I did get it to work but I don't have my code here, I will check for you later and post.

Re: QuadTerrain LOD: Finished

Justin Le Clair — Wed, 14 Oct 2009 19:58:07 GMT

Hey, I'm getting this error when I'm trying to get it going on my Xbox

An unhandled exception of type 'System.NotSupportedException' occurred in Microsoft.Xna.Framework.dll
Additional information: This functionality is not available on this platform.

at this line : normalTexture.GenerateMipMaps(TextureFilter.Anisotropic);

did you find a workaround for this?

Thanks,
Justin

Re: QuadTerrain LOD: Finished

TnTGaming — Tue, 13 Oct 2009 04:17:56 GMT

I actually have this working fine on the xbox 360 now. Took some fiddling with but I use sunburn rendering engine and I got your quad terrain to submit itself through the sunburn render manager actually. Now I just have to get sunburn to play nice with the quad terrains lighting and some other fixes to make it a fully integrated solution that will hopefully mix optimized heightmaps with the sexyness of sunburn.

Re: QuadTerrain LOD: Finished

Qu — Tue, 13 Oct 2009 02:59:30 GMT

TnTGaming: Sorry man, I don't own a 360, so I can't really help. To tell you the truth, I'm astonished that the demo even works on it.

If I ever get a 360, I'll look into it, but I don't think that'll happen any time soon. I simply don't have the money to spend.

Re: QuadTerrain LOD: Finished

Duallity — Mon, 12 Oct 2009 16:18:58 GMT

The reply is a bit late, but I wanted to tell you that my solution is not perfect yet.
Sure you can use power of two images now, but of cause there is now one pixel missing which means there is data missing.
The missing data results in a height of zero. This is not that bad if you only load a terrain once as you will never see this issue as its at the very end of the terrain. But I guess you will get problems if you dynamically add terrains and attach them.
I will try to solve this problem, but not in the next weeks.
When I did, I'll post it here of cause.

Greez
Duallity

Re: QuadTerrain LOD: Finished

TnTGaming — Tue, 06 Oct 2009 01:38:39 GMT

Has anyone got this working on the xbox 360? Any information would be great, I have the demo working on the 360 but can't get it working in my own game! Thanks.

Re: QuadTerrain LOD: Finished

Qu — Wed, 09 Sep 2009 22:51:14 GMT

Hey guys.

First: sorry for vanishing. Again. :rolls eyes: What with other stuff going on I completely forgot to visit the XNA forums for a few days, which somehow became a few months. You may commence kicking me whenever you feel like it.

Soo....

Duallity: n^2+1 was a result of necessity. You see, in order to build a quad tree the way I did, each node of vertices needs to be splittable into 4 smaller nodes, each of which shares sides. A tiny 3x3 vertex grid (1^2+1), can be split into 4 2x2 squares. A 5x5 (2^2+1) can be split into 4 3x3. And so on.

I realise you've already found a solution to this problem, and it's probably better than what I would have suggested, but I'll suggest it anyway: a custom content processor which adds an extra row of pixels to both edges, thus adding the (+1) to n^2 (+1).

Your solution was harder but better.

Defendered: I have very occasionally noticed a gap or two in the terrain over here too, but it's a lot less common than it use to be. If you make the background below the horison black, or add some sort of horison plain with a texture colour similar to what you're using on the QuadTerrain, it's a lot harder to spot when it happens. And if I ever find out what's causing it, I will fix it. And as Duallity said, the higher you increase the LOD value, the less often you're likely to see it.

tdogger: Okay! :D

Re: QuadTerrain LOD: Finished

tdogger — Sat, 05 Sep 2009 18:37:45 GMT

hey qu this is a bit irrelevant but aimed at getting your attention

could you check out my response in the "3d animation topic" that you were so helpful in?

Re: QuadTerrain LOD: Finished

Duallity — Thu, 06 Aug 2009 18:33:45 GMT

Well I don't see any gaps anywhere. Check if you LOD (it's set as parameter in the Update method) is 3.5f or higher.

Re: QuadTerrain LOD: Finished

defenderd — Thu, 06 Aug 2009 07:22:35 GMT

Thanks, Duality, for your reply.
I will try that ,but do you think that will resolve the gaps (there are some dots and sometimes some lines) which appear between textures ?

Anyway,thank you for your reply .I am new to XNA which I think is the greatest.This is why I ask probably noob questions...

Re: QuadTerrain LOD: Finished

Duallity — Wed, 05 Aug 2009 10:37:27 GMT

As Quasar does not answer I tryed changing his class by myself so I can use textures with H/W that are powers of two.
It's not really a solution, but it works for the moment.
First seach all the usages of 'heightmap.Height' and 'heightmap.width' and add 1 to them.

One exception is this line:

    
            VBuffer = (int)(Math.Floor(((float)(xPosition + 1) / heightMap.Width) * sqrtNumberOfVBs) + (Math.Floor(((float)(yPosition + 1) / heightMap.Height) * sqrtNumberOfVBs) * sqrtNumberOfVBs)) + 1;

Just let is as it is.

As the terrainwidth/height variables now have the value of the height/width +1 you have to change it back in some cases.

    
            Color[] heightMapColors = new Color[(terrainWidth-1) * (terrainHeight-1)]; 
        
            numberOfVBs = (int)Math.Pow((terrainHeight - 1) / (VBsize - 1), 2); 
        
            for (int y = 0; y < terrainHeight-1; y++) 
        
            { 
        
                 for (int x = 0; x < terrainWidth-1; x++) 
        
                 { 
        
                       //heightstore Array 
        
                       heightStore[x, y] = heightMapColors[x + y * (terrainWidth-1)].R; 
        
                  } 
        
            } 
        
            //This one is inside of two for-loops. The comment above them is: "Generate Vertex Positions and normals" 
        
            if (x > 0 && y > 0 && x < terrainWidth - 1 && y < terrainHeight - 1)

These are lines where you have to decrease the terrainwidth/height. The lines above are allready the changed ones, so yours should look like them.
I can't give you any line numbers as I've allready changed a few things, but I guess you'll find the lines when you search for 'terrainwidth/height'.

I hope I didn't forget a line, if so and you get an error at a line containing terrainwidth/height just decrease it by 1.

Greez

Duallity

Re: QuadTerrain LOD: Finished

defenderd — Mon, 03 Aug 2009 09:58:52 GMT

Qu:
Done, done and done! You can download the new version here, or via the link on the first page.

If you're already using it, upgrading should be a simple matter: the only changes are to the QuadTerrain.cs file, so just replace that. :)

Hello Qu,

I have downloaded your latest (I think) sample and run that.On the line 290 from QuadTerrain.cs I have replaced the numLevel parameter from 0 to 1 because of some power of two running error.See below:

normalTexture =

new Texture2D(g, heightMap.Width, heightMap.Height, 1, TextureUsage.AutoGenerateMipMap, SurfaceFormat.Color);

The thing is that I can still see the gaps (some points and some lines) in the terrain.
So,can you point me an workarround for this or if you are that kind to make an update with this issue...I have tested this on 2 computers so far ,and it is the same thing.

Thank you in advance,
defenderd

Re: QuadTerrain LOD: Finished

Duallity — Mon, 27 Jul 2009 15:51:53 GMT

Sure I could do this, I just wanted to talk to Quasar first, because, as you mentioned, you almost always want your textures to be a power of two. So I guess Quasar might be interested in changing that and realises a new official version for that.

Re: QuadTerrain LOD: Finished

Lord Ikon — Mon, 27 Jul 2009 12:30:00 GMT

Well, that isn't good. You almost always want your textures to be a power of two. I wish I'd had the time to get a dynamic LOD working with my terrain stuff. I had planned to take a look at this source and see if I would want to use it instead, or just use it to learn some LOD techniques from, but I just had no time with my long hours at work. You may be able to convert his whole source to use power-of-two textures. It'll probably require changing lots of little things throughout the code though.