3DS Loader very slow on ComputeNormals! Help!!
Author
Hello guys!
I have a problem with 3DS Loader from www.gametutorials.com
The Function ComputeNormals() is VERY VERY VERY slow for Hi Polygon Models.
I made 2-3 Spheres with sum vertices be 25.000. To compute the Normals
made about 22 seconds! And if I put more... oh.. i dont want to know...
It will be much more!Any idea how to speed up this function?
My CPU is an AMD Athlon Barton Core 512Cache 2000MHz with 200FSB
thank you!
you're right, digiben's averaging-normals-function is a mess.
i had the same problem with it. my comp needed between 60-90 seconds to compute models with 10k+ polys. so i rewrote it, now it takes about 2-3 seconds for the same models. but the source is kinda complicated and it doesnt determine hard edges (yet). but if you like, i can post it here nonetheless...
for now i can give you this link:
Smooth Normal Generation with Preservation of Edges
it's by Nate Robins. look for the file glm.c and for the function named glmVertexNormals(). i think that's all you'll need :)
i had the same problem with it. my comp needed between 60-90 seconds to compute models with 10k+ polys. so i rewrote it, now it takes about 2-3 seconds for the same models. but the source is kinda complicated and it doesnt determine hard edges (yet). but if you like, i can post it here nonetheless...
for now i can give you this link:
Smooth Normal Generation with Preservation of Edges
it's by Nate Robins. look for the file glm.c and for the function named glmVertexNormals(). i think that's all you'll need :)
Author
thats for the link man! But if you like post your way here to get some ideas.
thanks in advnace!
thanks in advnace!
well, you've asked for it! [smile]
please dont bitch about the source. the snippet is a part of a reeeally huge project of mine (my diploma thesis; game engine + game). some parts arent really polished because of the lack of time and all the code just had to work... blah.
please dont bitch about the source. the snippet is a part of a reeeally huge project of mine (my diploma thesis; game engine + game). some parts arent really polished because of the lack of time and all the code just had to work... blah.
void c_mesh_manipulator::smooth_normals( i_mesh* mesh, t_f32 angle_degree ){ debug_assert( mesh ); t_f32 angle = angle_degree * math::deg_to_rad_factor; std::vector < s_face_list > store; size_t i, j; size_t buffer_count = mesh->get_vertex_buffer_count(); for ( i = 0; i < buffer_count; ++i ) { i_vertex_buffer* buffer = mesh->get_vertex_buffer( i ); debug_assert( buffer ); vid::s_vertex_data& vertex_data = buffer->get_vertex_data(); math::t_vector3f* vertices = vertex_data.get_vertex_pointer(); t_u32 num_vertices = vertex_data.get_vertex_count(); vid::s_index_data& index_data = buffer->get_index_data(); t_u16* indices = index_data.get_index_pointer(); t_u32 num_indices = index_data.get_index_count(); t_u32 num_triangles = num_indices / 3; store.clear(); store.resize( num_vertices ); t_u16 a, b, c; s_face s; for ( j = 0; j < num_triangles; ++j ) { a = indices[ 3 * j + 0 ]; b = indices[ 3 * j + 1 ]; c = indices[ 3 * j + 2 ]; math::t_vector3f& v0 = vertices[ a ]; math::t_vector3f& v1 = vertices;<br> math::t_vector3f& v2 = vertices[ c ];<br> <br> s.idx = j;<br> s.a = a; s.b = b; s.c = c;<br> s.normal = ( v0 - v1 ).cross_product( v2 - v1 );<br> s.normal.normalize();<br> <br> store[ a ].list.push_back( s );<br> store.list.push_back( s );<br> store[ c ].list.push_back( s );<br> }<br> <br> <br> math::t_vector3f* normals = vertex_data.get_normal_pointer();<br><br> <span class="cpp-keyword">for</span> ( j = <span class="cpp-number">0</span>; j < num_vertices; ++j )<br> {<br> math::t_vector3f sum( <span class="cpp-number">0</span>, <span class="cpp-number">0</span>, <span class="cpp-number">0</span> );<br> <span class="cpp-keyword">bool</span> averaged = <span class="cpp-keyword">false</span>;<br> <span class="cpp-keyword">int</span> shared = <span class="cpp-number">0</span>;<br><br> size_t size = store[ j ].list.size();<br> <span class="cpp-keyword">for</span> ( size_t idx = <span class="cpp-number">0</span>; idx < size; ++idx )<br> {<br> s_face& tri = store[ j ].list[ idx ];<br> <br> <span class="cpp-comment">// TODO: determine hard edges here</span><br><br> sum += tri.normal;<br> ++shared;<br> }<br><br> t_f32 scale = -shared;<br> math::t_vector3f tv;<br> tv.x = sum.x / scale;<br> tv.y = sum.y / scale;<br> tv.z = sum.z / scale;<br> tv.normalize();<br><br> normals[ j ] = tv;<br> }<br> }<br>}<br><br></pre></div><!–ENDSCRIPT–> This topic is closed to new replies.
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