Irrlicth-Newton Demonstration with Irrlicht 1.4, Newton 1.53

[gbutcher]

I munged Mercior's demo to work:

Code: Select all

/* Updated Mercior's Irrlicht-Newton Demonstration
by Glenn Butcher, Jan 2008

Uses Irrlicht 1.4 and Newton 1.53, compiles with Mingw/DevC++
Major changes:
    - Change matrix4 to use theCMatrix4 template class
    - Padded the Newton world because the bsp size didn't include the initial crates
        (Shoot some crates over the wall, see what happens)
    - Added setMaterialFlag(EMF_LIGHTING, false) to MakeCube to light up the cube texture
    - Put it all in main.cpp so I could concentrate on finding the above...
        (Mercoir, I'm >50, don't think global variables, in moderation, are so bad  :D)
    
*/

#pragma comment(lib, "Irrlicht.lib")
#pragma comment(lib, "Newton.lib")

#define NEWTON_GRAVITY -800.0f

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>

// Irrlicht:
#include <irrlicht.h>
#include <wchar.h>

using namespace irr;
using namespace core;
using namespace scene;
using namespace video;
using namespace io;
using namespace gui;

// Newton:
#include <Newton.h>

	// Old man's cube class... 
	struct NewtonCube {
		IAnimatedMesh *mesh;
		ISceneNode *node;
		NewtonBody *body;
		NewtonCollision *collision;
	};
	NewtonCube *cubes[512];
	int currentCube;

	// Frame drawing variables:
	int lastFPS;
	u32 lasttick;

	// Irrlicht vars:
	IVideoDriver* driver;
	ISceneManager* smgr;
	IGUIEnvironment* guienv;
	IrrlichtDevice *device;

	// Newton vars:
	NewtonWorld *nWorld;

	// Our level:
	scene::IAnimatedMesh* g_map;
	scene::ISceneNode* g_mapnode;
	scene::ITriangleSelector *g_selector;
	NewtonCollision* g_newtonmap;
	NewtonBody* g_newtonmapbody;

	// Scene vars:
	ICameraSceneNode *cam;


void SetMeshTransformEvent(const NewtonBody* body, const float* matrix)
{
	// Instantiate Irricht CMatrix4 template as float, copy the matrix into it:
	// ggb: Old tutorial used matrix4
	CMatrix4<float> mat;
	mat.setM(matrix);

	// Retreive the user data attached to the Newton body:
	ISceneNode *tmp = (ISceneNode *)NewtonBodyGetUserData(body);
	if (tmp)
	{
		// Position the node:
		tmp->setPosition(mat.getTranslation());		// set position
		tmp->setRotation(mat.getRotationDegrees());	// and rotation
	}
}

void ApplyForceAndTorqueEvent (const NewtonBody* body)
{
	float mass;
	float Ixx;
	float Iyy;
	float Izz;
	float force[3];
	float torque[3];

	NewtonBodyGetMassMatrix (body, &mass, &Ixx, &Iyy, &Izz);

	force[0] = 0.0f;
	force[1] = NEWTON_GRAVITY * mass;
	force[2] = 0.0f;

	torque[0] = 0.0f;
	torque[1] = 0.0f;
	torque[2] = 0.0f;

	NewtonBodyAddForce (body, force);
	NewtonBodyAddTorque (body, torque);
}

NewtonCube* MakeCube(vector3df loc)
{
	NewtonCube *tmp = new NewtonCube;

	tmp->mesh = smgr->getMesh("data/smallcube.3ds");
	tmp->node = smgr->addAnimatedMeshSceneNode(tmp->mesh);
	tmp->node->setMaterialFlag(EMF_LIGHTING, false);
	tmp->node->setMaterialTexture(0, driver->getTexture("data/crate.jpg"));

	// Create a box primitive. 38 is just an estimated value of the size of the model:
	tmp->collision = NewtonCreateBox(nWorld, 38, 38, 38, NULL);
	tmp->body = NewtonCreateBody(nWorld, tmp->collision);

	// Set user data pointer to the scene node:
	NewtonBodySetUserData(tmp->body, tmp->node);

	// Set body mass & inertia matrix
	NewtonBodySetMassMatrix (tmp->body, 10.0f, 150.0f, 150.0f, 150.0f);

	// Set the freeze threshhold to 1 unit (default is 0.01 but irrlight uses a 
	// large unit scale):
	NewtonBodySetFreezeTreshold(tmp->body, 1.0, 1.0, 1);

	// Set callback functions for the body:
	NewtonBodySetTransformCallback(tmp->body, SetMeshTransformEvent);
	NewtonBodySetForceAndTorqueCallback(tmp->body, ApplyForceAndTorqueEvent);
	
	// Animate the body by setting the angular velocity - makes 'em spin!
	float omega[3]; omega[1] = 1.0f; omega[2] = 0.0f; omega[3] = 0.0f;
	NewtonBodySetOmega (tmp->body, &omega[0]);

	// Set the position of the body:
	CMatrix4<float> mat;
	//matrix4 mat;
	mat.setTranslation(loc);
	NewtonBodySetMatrix(tmp->body, mat.pointer());


	if (currentCube == 512)
	{
		printf("* Too many cubes!");
	}
	cubes[currentCube] = tmp;
	currentCube ++;

	return tmp;
}

class MyEventReceiver : public IEventReceiver
{
public:
	virtual bool OnEvent(const SEvent& event)
    {
	   if (event.EventType == irr::EET_MOUSE_INPUT_EVENT && event.MouseInput.Event == 
            EMIE_LMOUSE_PRESSED_DOWN)
	   {
		  // make a cube where the camera is and set its velocity to follow the target:
		  NewtonCube *tmp = MakeCube(cam->getPosition());
		  if (!tmp) return false;
		  vector3df camvec = (cam->getTarget() - cam->getPosition()).normalize() * 500;
		  float newpos[3] = { camvec.X, camvec.Y, camvec.Z };
		  NewtonBodySetVelocity(tmp->body, (float*)newpos);
	   }
	   return false;
    }
};


int main(int argc, char* argv[])
{

	// Init the Irrlicht engine:
	MyEventReceiver receiver;
	device = createDevice(EDT_OPENGL, dimension2d<s32>(800, 600), 16, false, true, false, &receiver);

	driver = device->getVideoDriver();
	smgr = device->getSceneManager();
	guienv = device->getGUIEnvironment();

	// Init Newton:
	nWorld = NewtonCreate(NULL, NULL);

	// Set up default material properties for Newton:
	int i = NewtonMaterialGetDefaultGroupID(nWorld);
	NewtonMaterialSetDefaultFriction   (nWorld, i, i, 0.8f, 0.4f);
	NewtonMaterialSetDefaultElasticity (nWorld, i, i, 0.3f);
	NewtonMaterialSetDefaultSoftness   (nWorld, i, i, 0.05f);
	NewtonMaterialSetCollisionCallback (nWorld, i, i, NULL, NULL, NULL, NULL);

	// Add the camera:
	cam = smgr->addCameraSceneNodeFPS();
	cam->setPosition(vector3df(0, 350, 0));

	// Initialize variables:
	lasttick = 0;
	currentCube = 0;

	// Add skybox:
	smgr->addSkyBoxSceneNode(driver->getTexture("data/irrlicht2_up.bmp"),
                            driver->getTexture("data/irrlicht2_dn.bmp"),
                            driver->getTexture("data/irrlicht2_lf.bmp"),
                            driver->getTexture("data/irrlicht2_rt.bmp"),
                            driver->getTexture("data/irrlicht2_ft.bmp"),
                            driver->getTexture("data/irrlicht2_bk.bmp"));

	// Load map:
	g_map = smgr->getMesh("data/physicstest.bsp");
	g_mapnode = smgr->addOctTreeSceneNode(g_map->getMesh(0));

	//////////////////////////////////////////////////////////////////////////
	//
	// Create the newton collision tree from the map mesh
	//
	// Remember to use (video::S3DVertex) if you are loading a mesh without 
	// lightmaps for your level. (Like a .x or .3ds level)
	//
	//////////////////////////////////////////////////////////////////////////
	g_newtonmap = NewtonCreateTreeCollision(nWorld, NULL);
	NewtonTreeCollisionBeginBuild(g_newtonmap);
	int cMeshBuffer, j;
	int v1i, v2i, v3i;
	IMeshBuffer *mb;

	float vArray[9]; // vertex array (3*3 floats)

	int tmpCount = 0;

	for (cMeshBuffer=0; cMeshBuffer<g_map->getMesh(0)->getMeshBufferCount(); cMeshBuffer++)
	{
		mb = g_map->getMesh(0)->getMeshBuffer(cMeshBuffer);

		video::S3DVertex2TCoords* mb_vertices = (irr::video::S3DVertex2TCoords*)mb->getVertices();

		u16* mb_indices  = mb->getIndices();

		// add each triangle from the mesh:
		for (j=0; j<mb->getIndexCount(); j+=3)
		{
			v1i = mb_indices[j];
			v2i = mb_indices[j+1];
			v3i = mb_indices[j+2];

			vArray[0] = mb_vertices[v1i].Pos.X;
			vArray[1] = mb_vertices[v1i].Pos.Y;
			vArray[2] = mb_vertices[v1i].Pos.Z;
			vArray[3] = mb_vertices[v2i].Pos.X;
			vArray[4] = mb_vertices[v2i].Pos.Y;
			vArray[5] = mb_vertices[v2i].Pos.Z;
			vArray[6] = mb_vertices[v3i].Pos.X;
			vArray[7] = mb_vertices[v3i].Pos.Y;
			vArray[8] = mb_vertices[v3i].Pos.Z;

			NewtonTreeCollisionAddFace(g_newtonmap, 3, (float*)vArray, 12, 1);
		}

	}
	NewtonTreeCollisionEndBuild(g_newtonmap, 0);
	g_newtonmapbody = NewtonCreateBody(nWorld, g_newtonmap);


	// Set the newton world size based on the bsp size:
	float boxP0[3];
	float boxP1[3];
	float matrix[4][4];
	NewtonBodyGetMatrix (g_newtonmapbody, &matrix[0][0]);
	NewtonCollisionCalculateAABB (g_newtonmap, &matrix[0][0],  &boxP0[0], &boxP1[0]);
	printf("min: %f,%f,%f  max: %f,%f,%f\n",boxP0[0],boxP0[1],boxP0[2],boxP1[0],
        boxP1[1],boxP1[2]);  //exposed the 'small world' problem...
	// You can pad the box here if you wish 
	// ggb: I spent a lot of time figuring out the initial boxes were outside the 
	//      Newton world bounded by the bsp size.  Just padded y by 1000 in both 
	//      directions to snag them.
	boxP0[1] -= 1000.0f;  //boxP0.y
	boxP1[1] += 1000.0f;  //boxP1.y
	NewtonSetWorldSize (nWorld, (float*)boxP0, (float*)boxP1);

	// Hide cursor:
	device->getCursorControl()->setVisible(false);

	// Make some cubes:
	int xo = 500, yo = 500;
	int x, y;
	for (x=0; x<10; x++)
	{
		for (y=0; y<10; y++)
		{
			MakeCube(vector3df((float)(x*100)-xo, 500.0f, (float)(y*100)-yo));
		}
	}

 
	// Main Loop:
	while(device->run())
	{
	   	driver->beginScene(true, true, video::SColor(0,220,220,255));

	   // Render the scene:
	   smgr->drawAll();

	   driver->endScene();

	   // Draw fps counter:
	   int fps = driver->getFPS();
	   if (lastFPS != fps)
	   {
		  wchar_t tmp[1024];
		  swprintf(tmp, 1024, L"Newton Example [fps:%d] [triangles:%d]",
		      fps, driver->getPrimitiveCountDrawn());
		  device->setWindowCaption(tmp);
		  lastFPS = fps;
	   }

	   // Update newton 100 times / second:
	   if (device->getTimer()->getTime() > lasttick + 10) {
		  lasttick = device->getTimer()->getTime();
		  NewtonUpdate(nWorld, 0.01f);
	   }
	}

	// Clean up memory:
        
	// Release the collision tree:
	NewtonReleaseCollision(nWorld, g_newtonmap);

	// Release the box primitives:
	for (int i=0; i<currentCube; i++)
		NewtonReleaseCollision(nWorld, cubes[i]->collision);

	// Finish Newton & Irrlicht:
	NewtonDestroy(nWorld);
	device->drop();

	return 0;
}

[Seven]

I have been using these types of tuts for a hosrt while now and have a nice little test bed created. Question though, how do you detect a collision between a node and the quake world. for example, in the following code, I load up a quake world and then have objects that I create bounce all over it. I can even detect when objects collide against each other, because I have newton materials assigned to them. What I would like to do is tell when the object hits the quake mesh, so that I can make it explode and whatnot.

Code: Select all

	virtual bool Create(CSLevel* level, int id, char* zipfile, char* levelname) {	
											CSObject::Create(level, id);

											video::IVideoDriver* driver = level->m_App->m_Engine->m_Driver;
											scene::ISceneManager* smgr = level->m_Smgr;
											scene::ICameraSceneNode* camera = level->m_Camera;

											/////////////////////////////////////////////////////////////
											//load a map as an oct tree scene node add a zip file
											level->m_App->m_Engine->m_Device->getFileSystem()->addZipFileArchive(zipfile);

											//get model mesh
											scene::IAnimatedMesh* world_mesh_anim = smgr->getMesh(levelname);

											//create the scene node
											m_Node = smgr->addOctTreeSceneNode(world_mesh_anim);
											
											// set whether light affects the node
											m_Node->setMaterialFlag(video::EMF_LIGHTING, false);

											//position the scene node
											m_Node->setPosition(core::vector3df(45,0,0));

											//let's create the body for our map
											//if we don't do this, the ellipsoid trought the map
											//the creation methos is the same
											irr::newton::SBodyFromNode mapData;
											mapData.Node = m_Node;
		
											//because the node is a oct tree scene node and not a simple scene node we need to pass the mesh also
											mapData.Mesh = world_mesh_anim->getMesh(0);
											mapData.Type = newton::EBT_TREE;

											//create the body
											irr::newton::IBody* world_p_node = level->m_NewtonWorld->createBody(mapData);

											//world_p_node->setUserData((void*)this);
											//world_p_node->setMaterial(level->Newton_Material_Quake);
											
											/////////////////////////////////////////////////////////////
											return true;			
										}

the code above kind of works, but the commented out materials code uses the mesh as a rectangle that encloses the entire quake world, not each individual wall.
any help is appreciated.

Seven

[gbutcher]

NewtonMaterialSetCollisionCallback(...)

I think this will do what you're looking for; register a function to be called upon a contact. I'm guessing however; the demo code I posted above is my first Newton effort...

g

[Seven]

Thanks for the reply. I do have the callbacks setup and working, but the quake node seems to get treated as a single rectangle for collision reaction. This causes the 'bullet' to hit the quake node total bounding box instead of a 'wall'. I can also have it hit just a wall, but when i do that, the frame rate slows to something awful. The end result is that i am doing something wrong I am sure, but I cant seem to find what it is.

[fabregot]

Code: Select all

float omega[3]; omega[1] = 1.0f; omega[2] = 0.0f; omega[3] = 0.0f; 

In this part on VS .NET 2003 crashes!

Change this for:

Code: Select all

float omega[3]; omega[1] = 1.0f; omega[2] = 0.0f; omega[0] = 0.0f; 

Because the '3' is out of index.

It's ok?

[Dorth]

Or maybe O[0] = 1.0f; etc. since it's the first of the array?

[Vsk]

you must create the terrain like a tree for newton look for tree bouding boxes.
Take a look at irrnewt wrapper for looking how it does that.

[etcaptor]

Full/advanced/ Newton integration with Irrlicht is "bpia" /big pain in ass"/ It is the last obstacle for my last project release. But it's almost complete. You must consider your collision type - box, sphere, cylinder, cone, mesh. For mesh type must check whether it octree or terrain. Also you must find vertex types of your mesh. Some problems are very strange/maybe Irrlicht bugs/ but for octree you must use IAnimatedMesh, and for terrain IMesh.
Also Newton design is not OOP .
When I see my wrappers I just foll in depression with all callbacks
I forgot that Irrlicht and Newton haves different scales. I forgot that when any Irrlicht mesh is resized you must recalculate newton rigid body. And many many related details. Yet I congratulate your for this topic. Let it's grown with all kind of these problems and solutions.

[Vsk]

Those problems that you name are all resolve in irrNewt (newton wrrapper).
If you don't want you use it and want do it one for yourself, it will be a extremly helpful aproach to take a look at, because it is OOP and has all problem tbat you name solved in high level, for example createing a convexhull, tree, compound etc. Realy practice at least to learn and take some ideas.
In fact you can take and better it, of course it need some upgrade.

I hope it help you.

[etcaptor]

Yeah, thanks. But I already finished with my own implementation last night. Will take a look there.

[Vsk]

Coud you pass me the function that you used to make convex hulls?
I mean the part that give the vertext to newton.
Because although this work in irrnewt quit well, I don't like the shape that it forms. Maybe IT IS in fact the form that it should form but maybe not and there is some vertex missing or something like that.

[etcaptor]

Yes, will post it tonight when going home. Done:
Here is this part of code and debug screen with sydney.md2 animated mesh. You can use convexhull modifier for response to any bounding box changes.

Code: Select all

//---------------------------------------------------------------------------
        case ID_CONVEXHULL:
        {
            IMeshBuffer *mb = NULL;
            int BufferCount = m_Mesh->getMeshBufferCount();
            array<vector3df> varray;

            for (int bi = 0 ; bi < BufferCount ; bi++)
            {
                mb = m_Mesh->getMeshBuffer(bi);
                int VerticleCount = mb->getVertexCount();
                varray.reallocate(varray.size()+ VerticleCount);

                switch(mb->getVertexType())
                {
                    case EVT_STANDARD:
                    {
                        S3DVertex* Vertices = (S3DVertex*)mb->getVertices();
                        for (int ii = 0 ; ii < VerticleCount ; ii++)
                        {
                            Vertices = (S3DVertex*)mb->getVertices();
                            for(int j=0;j< VerticleCount; j++)
                                varray.push_back( Vertices[j].Pos * IrrToNewton * m_ISceneNode->getScale());
                        }

                    }break;

                    case EVT_2TCOORDS:
                    {
                        S3DVertex2TCoords* Vertices = (S3DVertex2TCoords*)mb->getVertices();
                        for (int ii = 0 ; ii < VerticleCount ; ii++)
                        {
                            Vertices = (S3DVertex2TCoords*)mb->getVertices();
                            for(int j=0;j< VerticleCount; j++)
                            varray.push_back( Vertices[j].Pos * IrrToNewton * m_ISceneNode->getScale());
                        }
                    }break;
                };
            }

            Collision = NewtonCreateConvexHull(m_IrrNewtonWorld->GetNewtonWorld(), mb->getVertexCount(),&varray.pointer()->X ,sizeof(vector3df), NULL);
            m_ConvexHullModifier = NewtonCreateConvexHullModifier(m_IrrNewtonWorld->GetNewtonWorld(),Collision);
        } //END OF ID_CONVEXHULL

[B@z]

sry for the noobish question, but how can i move my model? O.o
i was searching all the time, but couldn't do it...

i saw it in the tutorial, but it was really hard... isn't there any easy way to do?

Code: Select all

void _cdecl CGame::ApplyForceAndTorqueEvent (const NewtonBody* body) 
{ 
   float mass; 
   float Ixx; 
   float Iyy; 
   float Izz; 
   float force[3]; 
   float torque[3]; 

   NewtonBodyGetMassMatrix (body, &mass, &Ixx, &Iyy, &Izz); 

   force[0] = 0.0f; 
   force[1] = NEWTON_GRAVITY * mass; 
   force[2] = 0.0f; 

   torque[0] = 0.0f; 
   torque[1] = 0.0f; 
   torque[2] = 0.0f; 

   NewtonBodyAddForce (body, force); 
   NewtonBodyAddTorque (body, torque); 
}

[sio2]

Yes, will post it tonight when going home. Done:
Here is this part of code and debug screen with sydney.md2 animated mesh. You can use convexhull modifier for response to any bounding box changes.

Code: Select all

//---------------------------------------------------------------------------
        case ID_CONVEXHULL:

Tip: Don't forget to test for and reject degenerate triangles.

[etcaptor]

Yes, thanks.