Bullet physics demo

[dlangdev]

Good work, but your taking a very minimalistic approach with your release aren't you? Why no executable? Without that, it's a lot of work just to use an updated Bullet library.

No executable code means a bar that they have to pass.

If they can deal with the code, that means they can do a lot of stuff with the demo code.

[dlangdev]

Hey, look, 96 downloads so far. Not sure why that number is 96, though.

[dlangdev]

Updates:

Adding CTerrainHeightMap is proving to be a hassle. Bullet is having a hard time setting up the triangles.

Maybe I should stick with simple terrain meshes with low polycount?

[dlangdev]

This demo went OK as it passed the basic test.

[MasterM]

Well the code is a little messy but understandable...but i still dont understand the concept behind porting bullet to irrlicht...some help here?

[m506]

Hey, anyone knows if Bullet can somehow load bmp heightmap files directly?

I know the latest version can load .raw files, but i use a heightmap generation library that only generates bmp.

Im sure that there also must be some way of passing the loaded bmp triangles from irrlicht to bullet, but i dont know how.

Please share some light on this
Thanks

[Dorth]

just convert the bmp to raw... Irrlicht has way better raw support now. (1.5)

[BlindSide]

Look at btHeightfieldTerrainShape for more information on loading terrains in Bullet.

[m506]

i didnt know that irrlicht had a native conversion function. i will try that.

thanks for replying

[m506]

Actually i couldnt find any function or way in neither irrlicht or bullet of converting bmp to raw of vice versa. does anyone know an effective way of doing that in real time?

Thanks for the help

[hybrid]

Once you've loaded the image, you can lock it and the resulting pointer points to RAW data.

[m506]

Hybrid;

Thanks for the response, but i am not quite sure what you mean by "lock it".

Do you mean that once the bmp data is loaded, the internal data structure can be considered as a raw file?

My main concern here is how to transform this bmp data into raw since bullet seems to only like raw. The code below is a sample on what i am using to load heightmap info with bullet:

Code: Select all

...
        FILE* heightfieldFile = fopen(filename,"r");
		
	if (heightfieldFile)
	{
		int numBytes = fread(heightfieldData,1,width*length,heightfieldFile);
		if (!numBytes)
		{
			printf("couldn't read heightfield at %s\n",filename);
		}
		fclose (heightfieldFile);
	}
	
	...
	
	btHeightfieldTerrainShape* heightFieldShape = new btHeightfieldTerrainShape(width,length,heightfieldData,maxHeight,upIndex,useFloatDatam,flipQuadEdges);;

Any help is appreciated
Regards

[hybrid]

Well, that's probably not possible then. What you'd get is a greymap with three or four color elements per pixel. Hence, the data would be completely wrong for this function, unless you can tell bt to interpret the data differently.

[m506]

yeah, I see what you mean;

What I will try then is getting the mesh out of the irrlicht terrain and pass it to bullet, even though this wouldnt be the most optimized solution.

What would you do if you had this issue anyway?

Regards

[Dorth]

Use a raw for the irrlicht map? Use the same color encoding? Get a gray version of the color map? strip irrelevant info? or alternatively add the missing one? A coder's job is to find solutions, come on, find some.