New Tiled Terrain Scene Node [works with Irr 1.5]

varholl · Post by **varholl** » Sun Jul 15, 2007 4:14 pm

Hi Arras.. i used your last code... but i-m having another issue.. i-m using a custom player Movement and camera position... (it's the one posted here.. as a WoW player movement..) and i need to create a TriangleSelector for the ShTlTerrainSceneNode.. but i' dont Know how to do it

Another things.. it seems that only loads one square of the Terrain.. maybe it's somethinhg easy to fix ... but i really didn't look at that...

monkeycracks · Post by **monkeycracks** » Sun Jul 15, 2007 4:22 pm

Put this in your main loop

vector3df pos = playernode->getPosition();
f32 height = terrain->getHeight(pos.X, pos.Z);
pos.Y = height;
playernode->setPosition(pos);

Don't need a triangle selector and it should work fine.

varholl · Post by **varholl** » Sun Jul 15, 2007 4:36 pm

Ok it Worked.. but the problem is that the source code i've used also manage the camera... and its really fun.. but the cam gets the gravitation and falls to the infinity

this is the code that uses the triangle Selector in that source code...

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void SetGround(IrrlichtDevice *dev1,ShTlTerrainSceneNode *ground1){
	if(ground1){
	MyDevice=dev1;
	if(ground1==MyFloorTerrain)return;
	MyFloorTerrain=ground1;
	MyFloor	= MyDevice->getSceneManager()->createTerrainTriangleSelector(ground1, 0);
	}
	}

I wonder if doing this "MyFloor = ground1->getTriangleSelector()" it could help in anyway i-ve tried without results

Maybe i have to do the same you told me with my camera code??

varholl · Post by **varholl** » Sun Jul 15, 2007 6:35 pm

Sorry for my double post... but i want to post some screenshots of my problem..

What can it be??

My code is like this..

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ShTlTerrainSceneNode* terrain = new ShTlTerrainSceneNode(smgr, 255, 255, 1, 100); 
terrain->drop();
// load height data from texture 
terrain->loadHeightMap("media/mapafinal2.bmp", 10);  
// load color map 
terrain->loadColorMap("media/nokturna_TX.jpg"); 
// set detail texture 
terrain->setMaterialTexture(0, driver->getTexture("media/detailmap3.jpg")); 
// smooth normals 
terrain->smoothNormals(); 
terrain->setMaterialFlag(video::EMF_LIGHTING, false);

My texture is a jpg of 2048 x 2048 pixels.. and my heightmap is bmp of 256 x 256 pixels...

Thanks in advance!

arras · Post by **arras** » Sun Jul 15, 2007 7:41 pm

monkeycracks >> use stretchTexture(core::vector2d<f32>(scaleX, scaleY));

varholl >> I dont know if Irrlicht TriangleSelector will work with my terrain node. It was not intended to. For placing Sidney on terrain use code monkeycracks was posting here. It places Sidney on the terrain. You may need to use some offset however if origin of Sidney model is in its center and not at its feet (witch seems to be problem on your screenshots):

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vector3df pos = playernode->getPosition();
f32 height = terrain->getHeight(pos.X, pos.Z);
pos.Y = height + offset;
playernode->setPosition(pos);

Howe much offset is depend on your model. Try diferent values to get right one for Sidney. In general it should be distance from origin to lowest wertice of model.

BlindSide · Post by **BlindSide** » Sun Jul 15, 2007 11:40 pm

monkeycracks, I recommend using the randomizeUV function thats included with the demo code. Its very useful and makes the terrain appear more detailed without any extra work.

Cheers

varholl · Post by **varholl** » Mon Jul 16, 2007 2:19 am

Thanks arras... anyway... my real problem is that the terrain is not loading entirely... i don't know why.. maybe i must create the heightmap in a special way... do you know why could it be?

EDIT:

If you see the screenshots... it seems that the texture is loaded as a plane square... but if i move around... the node get the right height for the terrain... for one reason... it's not working properly and i can't figure out why

2nd EDIT:

Another issue... when i start to walk in the terrain (no matter it's not working i tested it..) when i got position 256, 256... i get this error ..

"Unhandled exception at 0x0041007b in Nokturna.exe: 0xC0000005: Access violation reading location 0xababb37b."

and Vs2005 goes to this method..

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f32 ShTlTerrainSceneNode::getHeight(u32 w, u32 h)
{
    return Data(w,h).Height;
}

Sorry for all this questions.. but i really want to use this tiled terrain...

BlindSide · Post by **BlindSide** » Mon Jul 16, 2007 4:48 am

The terrain node size is actauly from 0. So I think if you have a heightmap of 256x256, the node sees the positions as 0-255 so you must make the terrain size 255x255 and not exceed this limit.

Cheers

arras · Post by **arras** » Mon Jul 16, 2007 8:21 am

BlindSide >> randomize function work with texture made for demo. Texture is actualy made from 4 tiles, each made of seamles texture. If you would use it with ordinary texture, like one in Irrlicht terrain demo, you would get wrong results.

Randomize function cuts texture in to 4 pieces and put randomly each over diferent tiles.

varholl >> you are using wrong function. One you are using is f32 ShTlTerrainSceneNode::getHeight(u32 w, u32 h) which return height of tile corners. You need to use f32 ShTlTerrainSceneNode::getHeight(core::vector3df pos) which accepts position in 3D (can be your player node) and returns real height of terrain at that place.

Use code monkeycracks was posting.

my real problem is that the terrain is not loading entirely

please, describe what it means exactly in more detail.

it seems that the texture is loaded as a plane square... but if i move around... the node get the right height for the terrain... for one reason... it's not working properly and i can't figure out why

describe that more too, I dont realy get what your problem is. Do you mean height map texture?

Sorry for all this questions

No problem, thats for what this forum is, place to ask questions and get answers. I'm glad to help. Many people helped me the same way.

elvman · Post by **elvman** » Mon Jul 16, 2007 9:16 am

I dont know if Irrlicht TriangleSelector will work with my terrain node. It was not intended to. For placing Sidney on terrain use code monkeycracks was posting here. It places Sidney on the terrain. You may need to use some offset however if origin of Sidney model is in its center and not at its feet (witch seems to be problem on your screenshots):

It works, I am using triangle selectors with your terrain in my project. I will post the code here when I will have some spare time.

arras · Post by **arras** » Mon Jul 16, 2007 11:53 am

elvman >> I am looking forward to it

varholl · Post by **varholl** » Mon Jul 16, 2007 1:17 pm

arras wrote: varholl >> you are using wrong function. One you are using is f32 ShTlTerrainSceneNode::getHeight(u32 w, u32 h) which return height of tile corners. You need to use f32 ShTlTerrainSceneNode::getHeight(core::vector3df pos) which accepts position in 3D (can be your player node) and returns real height of terrain at that place.

Ok.. i'll try it

arras wrote:
my real problem is that the terrain is not loading entirely
please, describe what it means exactly in more detail.

Well.. let me explain it better (sorry but english is not my mother tong

)

If i use a heightmap normally... and i set scale to 400,10,400 then my result is a big large and enourmus terrain...
I want to make the same thing with your tiled terrain... but the heightmap is really small.. and i don't know how to make it bigger... if i see your screenshot.. i see a large terrain with a depth view of the horizon... and if you see my screenshot.. is only a small square... i want to make it bigger but don't know how...

arras wrote:
it seems that the texture is loaded as a plane square... but if i move around... the node get the right height for the terrain... for one reason... it's not working properly and i can't figure out why
describe that more too, I dont realy get what your problem is. Do you mean height map texture?

Maybe my problem was that getHeight... if i can resolve my last issue this will be resolved to..

Thanks in advance and hope to explain myself better..

[/quote]

monkeycracks · Post by **monkeycracks** » Mon Jul 16, 2007 1:55 pm

Another question I have :

Is there a way to have two detail maps applied to one terrain? Such as a rocky detailmap tiled over a mountain part and a grassy detailmap tiled over the grassy part

varholl · Post by **varholl** » Mon Jul 16, 2007 2:38 pm

Can anyone post an example, of generating a tiled terrain based on a heightmap and some tiles??? I can't understand how to use it.. and no matter what i get always the same result.. so i'm start thinking i'm the problem, maybe i'm not using it as i should..

arras · Post by **arras** » Mon Jul 16, 2007 4:45 pm

monkeycracks >> yes, thats exactly what this node was made for. You have to put all your textures in to one bitmap. In your case rocks and grass. This will result in to detail texture made of subtiles (texture tiles, not terrain tiles). Then you can use seweral functions which manipulate texture UV coordinates to display correct texture tile on tiles you want. Grass on flat tiles, rocks on angled tiles for example. Function which lets you do it is setTileUV().

Of course in case of 2 diferent detail textures (rocks, grass) you want to create transitional textures (texture tiles) so on tiles where rocks and grass meets, they blend smoothly. My TXTBlend tool does make such set of textures out of two diferent ones automaticly: helps.http://irrlicht.sourceforge.net/phpBB2/ ... highlight= You just have to put them together.

In my demo, detail texture is also made of tiles. In this case 4 diferent tiles. They did not represent 4 diferent materials however, rather 4 variants of the same material which are randomly applied ower tiles in order to get some wariability. You may look at randomizeUV() function in someFunctions.h to get idea of howe to cut texture in to tiles and howe to apply them ower individual tiles.

This method of texture blending is quit old and is not without flaws, but it works. (I was trying diferent aproaches but due to some bugs in Irrilicht I kept with this one). In future I plan to change it and make easier.

varholl >> size and shape of your terrain seems to be result of wrong arguments passed in to constructor.
You construct terrain like:

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ShTlTerrainSceneNode* terrain = new ShTlTerrainSceneNode(smgr, width, height, tilesize, visiblemeshsize);

smgr is pointer to scene manager
width and height are dimension of your whole terrain
tilesize is size of single tile, terrain is made of. Tile is square, means its width and height are equal, thats why only one argument.
visiblemeshsize is dimension of part of terrain which will be actualy rendered. Its also square.

So lets consider example:

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ShTlTerrainSceneNode* terrain = new ShTlTerrainSceneNode(smgr, 255, 127, 10, 50);

In this case terrain will be255 x 127 tiles large, but only its portion 50 x 50 tiles will be wisible at any one time. Since tile is 10 x 10 units large, total dimension of whole terrain will be 2550 x 1270 units but only 500 x 500 units large square will be rendered.

Now you want your height map to be loaded:

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terrain->loadHeightMap("heightmap.bmp", 10, 0, 0);

heightmap.bmp is picture 256 x 128 pixels large. Note that we created terrain 255 x 127 tiles large. This means that terrain is exactly the size of height map. As you see size of terrain is one tile less than number of pixels. Thats because height is not applied to tiles itself but rather to its corners. I call those places where tilles meet, spots. And if you would draw simple image of such terrain made of tiles you can see that number of spots on each axis is always one biger than number of tiles.

Second argument is 10. This is scale and controls howe height data from heightmap will be applied on to terrain. Since height is loaded from color value of pixels in heightmap, it can be something between 0-255. 0 represents black, while 255 represent white. Scale 10 means that color 0 will be loaded as height 0 and color 255 will be loaded as height 10. Color 127 would translate in to height 5.

If for example scale would be 1, this would results in to fairly flat terrain since maximum height (black color) will be 1. As we have tiles 10x10 large, this is not a lot.

Size of terrain does not have to be the same as size of heightmap. My node lets you create large terrain and then load its height data from seweral heightmaps. Thats for what loadHeightMap() have those two last arguments. In example above these are 0, 0 and those are coordinates of spot, where you want your heightmap to be loaded.

For example you have 4 heightmaps: heightmap1.bmp, heightmap2.bmp,heightmap3.bmp,heightmap4.bmp. Each is 128x128 pixels large. Now you want terrain 255x255 tiles large to be created out of them:

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ShTlTerrainSceneNode* terrain = new ShTlTerrainSceneNode(smgr, 255, 255, 10, 50);
terrain->loadHeightMap("heightmap1.bmp", 10, 0, 0);
terrain->loadHeightMap("heightmap2.bmp", 10, 128, 0);
terrain->loadHeightMap("heightmap3.bmp", 10, 0, 128);
terrain->loadHeightMap("heightmap4.bmp", 10, 128, 128);

Hope this helps.

BTW: there is example code on page 5 of this post, which shows howe to create terrain from heightmap.