OPCODE question

Engines and Middleware Programming

Started by kandemor November 25, 2004 09:55 AM

1 comment, last by kandemor 19 years, 4 months ago

122

Author

November 25, 2004 09:55 AM

Hello, I'm trying to add a collision system based on Opcode in my engine. I've downloaded the 1.3 version and the user's manual, but it's the user's manual of the 1.2 version and I think some things have changed. Can someone help me, please? Where can I find information about the 1.3 version? And some sample code? Thank you! VinCenT

codemonster

595

November 29, 2004 05:01 AM

Indeed, the Opcode docs are awful. The Open Dynamics Engine uses Opcode optionally. Download the ODE source and have a look into the file named collision_trimesh.cpp.

Here's a small example using Opcode 1.3 I wrote earlier this year. It's by far not complete (and there may be bugs), but it worked and I didnt need more functionality at the time. The Opcode parts/classes you are looking for either begin with Opcode:: or uppercase letters. All the lowercased classes etc. are from my project and shouldnt really bother you.

Header:

namespace coll{	class c_triangle_manager : public i_triangle_manager	{		public:			c_triangle_manager( scene::i_mesh* mesh, const math::c_matrix* transformation );			virtual ~c_triangle_manager();						virtual bool get_colliders( const math::t_spheref& sphere, Opcode::SphereCache& cache, Opcode::SphereCollider& collider );			virtual bool get_colliders( const math::t_aabb3df& box, Opcode::AABBCache& cache, Opcode::AABBCollider& collider );			virtual bool get_colliders( const math::c_ray& ray, Container& container, Opcode::RayCollider& collider );			d_forceinline virtual const math::t_aabb3df&					get_bounding_box()      const { return m_bbox; }			d_forceinline virtual const std::vector < Point >&				get_vertices()          const { return m_list_of_vertices; }			d_forceinline virtual const std::vector < IndexedTriangle >&	get_indexed_triangles() const { return m_list_of_triangles; }					private:			math::t_aabb3df					m_bbox;			Opcode::Model					m_model;			Opcode::MeshInterface			m_imesh;			std::vector < Point >			m_list_of_vertices;			std::vector < IndexedTriangle >	m_list_of_triangles;	};}

Implementation:

namespace coll{	c_triangle_manager::c_triangle_manager( scene::i_mesh* mesh, const math::c_matrix* transformation )	{		debug_assert( mesh );		size_t idx_count = 0;		m_bbox.reset( 0.1f, 0.1f, 0.1f );		t_u32 count = mesh->get_submesh_count();		for ( t_u32 idx = 0; idx < count; ++idx )		{			scene::i_submesh* buffer = mesh->get_submesh( idx );			if ( buffer )			{				vid::s_vertex_data& vertex_data = buffer->get_vertex_data();				vid::s_index_data&  index_data  = buffer->get_index_data();				t_s32 vertex_count = vertex_data.get_vertex_count();				t_s32 index_count  = index_data.get_index_count();				t_u16* indices = index_data.get_index_pointer();				math::t_vector3f* vertices = vertex_data.get_vertex_pointer();				debug_assert( vertices );				t_u32 i0, i1, i2;								Point pt;				math::t_vector3f v;									size_t i;								for ( i = 0; i < index_count; i+=3 )				{					i0 = indices;<br>					i1 = indices;<br>					i2 = indices;<br>					<br>					v = vertices[ i0 ];<br>					m_bbox.insert( v );<br>					pt.x = v.x; pt.y = v.y; pt.z = v.z;<br>					m_list_of_vertices.push_back( pt );<br><br>					v = vertices[ i1 ];<br>					m_bbox.insert( v );<br>					pt.x = v.x; pt.y = v.y; pt.z = v.z;<br>					m_list_of_vertices.push_back( pt );<br>					<br>					v = vertices[ i2 ];<br>					m_bbox.insert( v );<br>					pt.x = v.x; pt.y = v.y; pt.z = v.z;<br>					m_list_of_vertices.push_back( pt );<br><br>					m_list_of_triangles.push_back( IndexedTriangle( idx_count+<span class="cpp-number">0</span>, idx_count+<span class="cpp-number">1</span>, idx_count+<span class="cpp-number">2</span> ) );<br>					idx_count+=<span class="cpp-number">3</span>;<br>				}<br><br>			}<br>		}<br><br>		m_imesh.SetNbTriangles( m_list_of_triangles.size() );<br>		m_imesh.SetNbVertices( m_list_of_vertices.size() );<br><br>		<span class="cpp-keyword">if</span> ( !m_imesh.SetPointers( &amp;m_list_of_triangles[ <span class="cpp-number">0</span> ], &amp;m_list_of_vertices[ <span class="cpp-number">0</span> ] ) )<br>		{<br>			<span class="cpp-comment">// TODO</span><br>		}<br><br>		udword degenerate = m_imesh.CheckTopology();<br>		<span class="cpp-keyword">if</span> ( degenerate )<br>		{<br>			<span class="cpp-comment">// TODO</span><br>		}<br>		<br>		Opcode::OPCODECREATE opcc;<br><br>		opcc.mIMesh         = &amp;m_imesh;<br>		opcc.mNoLeaf        = <span class="cpp-keyword">true</span>;<br>		opcc.mQuantized     = <span class="cpp-keyword">true</span>;<br>		<span class="cpp-comment">//opcc.mCollisionHull = false;</span><br>		opcc.mKeepOriginal  = <span class="cpp-keyword">false</span>;<br>		opcc.mCanRemap      = <span class="cpp-keyword">true</span>;<br><br>		<br>		<span class="cpp-keyword">if</span> ( !m_model.Build( opcc ) )<br>		{<br>			<span class="cpp-comment">// TODO</span><br>		}<br>	}<br>	<br>	<br>	c_triangle_manager::~c_triangle_manager()<br>	{<br>	}<br><br>	<br>	<span class="cpp-keyword">bool</span> c_triangle_manager::get_colliders( <span class="cpp-keyword">const</span> math::t_spheref&amp; sphere, Opcode::SphereCache&amp; cache, Opcode::SphereCollider&amp; collider )<br>	{<br>		Point center( sphere.center.x, sphere.center.y, sphere.center.z );<br>		Sphere s( center, sphere.radius );<br><br>		<span class="cpp-keyword">return</span> collider.Collide( cache, s, m_model );<br>	}<br><br><br>	<span class="cpp-keyword">bool</span> c_triangle_manager::get_colliders( <span class="cpp-keyword">const</span> math::t_aabb3df&amp; box, Opcode::AABBCache&amp; cache, Opcode::AABBCollider&amp; collider )<br>	{<br>		Point min;<br>		min.x = box.min.x;<br>		min.y = box.min.y;<br>		min.z = box.min.z;<br><br>		Point max;<br>		max.x = box.max.x;<br>		max.y = box.max.y;<br>		max.z = box.max.z;<br><br>		AABB aabb;<br>		aabb.SetMinMax( min, max );<br><br>		<span class="cpp-keyword">return</span> collider.Collide( cache, aabb, m_model );<br>	}<br><br><br>	<span class="cpp-keyword">bool</span> c_triangle_manager::get_colliders( <span class="cpp-keyword">const</span> math::c_ray&amp; ray, Container&amp; container, Opcode::RayCollider&amp; collider )<br>	{<br>		Point origin;<br>		origin.x = ray.origin.x;<br>		origin.y = ray.origin.y;<br>		origin.z = ray.origin.z;<br><br>		Point direction;<br>		direction.x = ray.normal.x;<br>		direction.y = ray.normal.y;<br>		direction.z = ray.normal.z;<br><br>		Ray opray( origin, direction );<br><br>		<span class="cpp-keyword">return</span> collider.Collide( opray, m_model );<br>	}<br><br>}<br><br></pre></div><!–ENDSCRIPT–><br><br>Usage:<br><small>i removed some parts in the following code snippet to make the usage clearer…</small><br><!–STARTSCRIPT–><!–source lang="cpp"–><div class="source"><pre><br>math::t_vector3f       position;<br>math::t_spheref        sphere;<br>Opcode::SphereCache    cache;<br>Opcode::SphereCollider collider;<br>coll::i_triangle_manager* tmgr;<br><br><span class="cpp-comment">// removed code for clarity</span><br><br><span class="cpp-keyword">if</span> ( tmgr )<br>{<br>	sphere.center.set( position.x, position.y, position.z );<br>	sphere.radius = m_bsphere_radius;<br><br>	<span class="cpp-keyword">bool</span> result = tmgr-&gt;get_colliders( sphere, cache, collider );<br>	<br>	<span class="cpp-keyword">if</span> ( result )<br>	{<br>		udword nbtouched = collider.GetNbTouchedPrimitives();<br><br>		<span class="cpp-keyword">if</span> ( nbtouched )<br>		{<br>			<span class="cpp-comment">// even more removed code…</span><br>		}<br>	}<br>}<br><br></pre></div><!–ENDSCRIPT–><br><br>This really isnt the best or cleanest example that was ever created, so please use with care. But I hope it helps anyway…<br>