[solved] Minimum needs to display Mesh (Writing FileLoader)

L o · Post by **L o** » Sat Apr 04, 2009 12:57 pm

Sorry I have to ask again.

I just cannot put textures on the faces.

	
	vertbuf->Material.MaterialType = video::EMT_SOLID;

	vertbuf->Material.Shininess = 20.0f;
	vertbuf->Material.SpecularColor.set(255,255,255,255);

	vertbuf->Material.setFlag(video::EMF_LIGHTING, true); // enable dynamic lighting

	video::ITexture* sample_texture = 
		SceneManager->getVideoDriver()->getTexture("/home/philipp/cprogs/ODF/odfl_reader/fake_texture.tga");

(whereas vertbuf is my meshbuffer)

The result: the whole level has the same color and it does not look like any of my textures.

I tried looking into the documentation, but I only found the Doxygen-stuff. Aren't there any tutorials about writing a meshloader?

hybrid · Post by **hybrid** » Sat Apr 04, 2009 3:50 pm

Just check the SMaterial API, you'll find a place to attach the textures.

L o · Post by **L o** » Sat Apr 04, 2009 3:55 pm

Oh sorry, I forgot to post this line:

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vertbuf->Material.setTexture(triangle_count, sample_texture);

(whereas triangle_count is iterated in a for-loop)

What's missing?

hybrid · Post by **hybrid** » Sat Apr 04, 2009 5:32 pm

triangleCount? You should use 0 for most material types. Iterate over the meshbuffers/materials for other parts of the mesh.

L o · Post by **L o** » Sat Apr 04, 2009 5:59 pm

Shall I create a meshbuffer for each material? Because, I don't see a function in the meshbuffer which lets me append a texture to a specified face.

hybrid · Post by **hybrid** » Sat Apr 04, 2009 8:30 pm

Yes, that's exactly the idea with meshbuffers. There are several reasons why you want to add a new meshbuffer. Logical grouping is one, but the main reason is to add a new material. Meshbuffers have the same material for all faces of that buffer.

L o · Post by **L o** » Sun Apr 05, 2009 10:29 am

So does it mean that some meshbuffers contain the same verts? Did I get that right? oO

So for sharing memory, could I put a vector of vertices into my loader and then just give the references to each meshbuffer? Is it allowed to put multiple references on one variable in C++? oO

hybrid · Post by **hybrid** » Sun Apr 05, 2009 10:45 am

If you have multiple materials at the very same 3d position you'd need duplicated vertices, one for each mehsbuffer. Don't know what you mean by references in this context.

L o · Post by **L o** » Sun Apr 05, 2009 12:33 pm

core::array wants a reference:

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void 	push_back (const T &element)

So can I have a vertices and then push back its references in different arrays? (because I get strange valgrind SIGSEGV errors after the mesh is loaded)

L o · Post by **L o** » Sun Apr 05, 2009 1:20 pm

OK, I found out that two references on the same variable are allowed.

Now that I put all in seperate meshbuffers, it is displayed wrong. Valgrind says, that memory is accessed which was deleted, which was latelely allocated using the push_back() function:

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face_buffer->Vertices.push_back( odfl_verts.at(second_point) );

These segfault errors occur AFTER the mesh is loaded.

Is a reallocation segfault issue known?

L o · Post by **L o** » Thu Apr 09, 2009 10:09 pm

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	for(unsigned int count2=0; count2 < face_count; ++count2)
	{
	
		SMeshBuffer* face_buffer = new SMeshBuffer;
		
		ODFLFile->read(&connects, 2);
		short start_point, second_point, third_point;
		
		ODFLFile->read(&start_point, 2);
		ODFLFile->read(&second_point, 2);
		
		face_buffer->Vertices.push_back(odfl_verts.at(start_point) );
		face_buffer->Vertices.push_back(odfl_verts.at(second_point) ); // !!!
		
		for(short connect_count=1; connect_count < connects-1; ++connect_count)
		{
			ODFLFile->read(&third_point, 2);

			face_buffer->Vertices.push_back( odfl_verts.at(third_point) );

			face_buffer->Indices.push_back(start_point);
			face_buffer->Indices.push_back(second_point);
			face_buffer->Indices.push_back(third_point);

         second_point = third_point;
			++triangle_count;
		}
		
		odfl_faces.push_back(tmp_face);
		
		
	   mesh->addMeshBuffer(face_buffer); 
		face_buffer->drop();
		
	}

The line with the !!! seems to cause the segfault. The vertice I push back is ok, so I think the face_buf->Vertices is the problem.

L o · Post by **L o** » Sat Apr 11, 2009 4:49 pm

Please Help Me

hybrid · Post by **hybrid** » Sat Apr 11, 2009 8:47 pm

Well, your second index seems out-of-bounds. Simple like that.

L o · Post by **L o** » Sat Apr 11, 2009 9:38 pm

No, definetely not. It would have throw()n an exception in this case.

hybrid · Post by **hybrid** » Sat Apr 11, 2009 11:36 pm

Well, push_back won't bail out either.