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Robo-Link

OpenGL Problem loading .obj model. Please help.

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I am trying to create a simple program that displays models and such (Think of it as a game without any actual "game"). I'm using the Ne(w)He second lesson as my base, but I've managed to use SOIL for textures, and use a greatly modified readFile function to load custom files in perfectly. However, I am currently trying to load a .obj file created from Animator, and it's not working right. These are the structs I'm using:

struct Vertex
		{
			float x, y, z;

			Vertex(float x, float y, float z)
			{
				this->x = x;
				this->y = y;
				this->z = z;
			}
		};

		struct uv
		{
			float u, v;

			uv(float u, float v)
			{
				this->u = u;
				this->v = v;
			}
		};

		struct part
		{
			std::vector<Vertex> m_Vertices; //We have a vector of vertices, each vertex with its 3 coordinates
			//std::vector<Vertex> m_Colors; //also 3 floats for colors, so we just use the Vertex-struct
			std::vector<Vertex> m_Normals; //also 3 floats for colors, so we just use the Vertex-struct
			std::vector<uv> m_uvcords; // vector of uv maps
			GLuint tex_2d;
			int vertices;

			part()
			{

			}

			~part()
			{
				this->m_Vertices.clear();
			//	this->m_Colors.clear();
				this->m_uvcords.clear();
				this->m_Normals.clear();
				this->tex_2d = NULL;
				this->vertices = 0;

			}
		};

		std::vector<part> m_parts;




And this is the readFile function:
Lesson02::part Lesson02::readFile(const char *filename)
{
	Lesson02::part temp;
	Lesson02::part temp2;
	float x, y, z, u, v, r, g, b;
	int texpoints;
	int normals;
	int numfaces;
	int t1, t2 = 0;
	FILE *filein;
	char oneline[255];
	int faces[12][5][3];
	filein = fopen(filename, "rt");				// File To Load World Data From

	readstr(filein,oneline);
	sscanf(oneline, "No. points %d:\n", &temp.vertices);

	cout << temp.vertices << endl;

	//readstr(filein,oneline);
	//sscanf(oneline, "TEX %d %d\n", &t1, &t2);
	
	temp2.tex_2d = SOIL_load_OGL_texture
		(
			readTexName(0, 2).c_str(),
			SOIL_LOAD_AUTO,
			SOIL_CREATE_NEW_ID,
			SOIL_FLAG_MIPMAPS | SOIL_FLAG_NTSC_SAFE_RGB | SOIL_FLAG_COMPRESS_TO_DXT
		);

	
	cout << readTexName(t1, t2) << endl;

	//glBindTexture( GL_TEXTURE_2D, tex_2d );

	for (int i = 0; i < temp.vertices; i++)
	{
			readstr(filein,oneline);
			sscanf(oneline, "v %f %f %f", &x, &y, &z);
			cout << x << " " << y << " " << z << endl;
			temp.m_Vertices.push_back(Vertex( x, y, z)); 
	}

	cout << "V  NORMAL MAP  V"<< endl;

	readstr(filein,oneline);
	sscanf(oneline, "No. normals %d:\n", &normals);

	for (int i = 0; i < normals; i++)
	{
			readstr(filein,oneline);
			sscanf(oneline, "vn %f %f %f", &x, &y, &z);
			cout << x << "n" << y << "n" << z << endl;
			temp.m_Normals.push_back(Vertex( x, y, z)); 
	}

	cout << "V  UV MAP  V"<< endl;

	readstr(filein,oneline);
	sscanf(oneline, "No. texture coordinates %d:\n", &texpoints);

	for (int i = 0; i < texpoints; i++)
	{
			readstr(filein,oneline);
			sscanf(oneline, "vt %f %f", &u, &v);
			cout << u << " " << v << endl;
			temp.m_uvcords.push_back(uv(u, v)); 
	}

	cout << "V  FACES MAP  V"<< endl;

	readstr(filein,oneline);
	sscanf(oneline, "No. faces %d:\n", &numfaces);

	for (int i = 0; i < numfaces; i++)
	{
			readstr(filein,oneline);
			sscanf(oneline, "f %d/%d/%d %d/%d/%d %d/%d/%d %d/%d/%d %d/%d/%d", &faces[i][0][0], &faces[i][0][1], &faces[i][0][2],
				&faces[i][1][0], &faces[i][1][1], &faces[i][1][2],&faces[i][2][0], &faces[i][2][1], &faces[i][2][2],
				&faces[i][3][0], &faces[i][3][1], &faces[i][3][2], &faces[i][4][0], &faces[i][4][1], &faces[i][4][2]);
			
			cout << "f " << faces[i][0][0] << "/" << faces[i][0][1]<< "/" <<faces[i][0][2]<< " " <<
				faces[i][1][0] << "/" << faces[i][1][1] << "/" << faces[i][1][2] << " " << faces[i][2][0] << "/" 
				<< faces[i][2][1] << "/" << faces[i][2][2] << " " << faces[i][3][0] << "/" << faces[i][3][1] << "/" << faces[i][3][2]
			<< " " << faces[i][4][0] << "/" << faces[i][4][1] << "/" << faces[i][4][2] << endl;
			//temp.m_uvcords.push_back(uv(u, v)); 
	}

	temp2.vertices = temp.vertices;

	for (int i = 0; i < numfaces; i++)
	{
		for(int j = 0; j < 5; j++)
		{
			cout << "F Vert " << i << " " << j << ": " << faces[i][j][0] << endl;
			cout << "F Norm " << i << " " << j << ": " << faces[i][j][2] << endl;
			cout << "F Tex " << i << " " << j << ": " << faces[i][j][1] << endl;
			
	
			temp2.m_Vertices.push_back(temp.m_Vertices[(faces[i][j][0] - 1)]);
			temp2.m_uvcords.push_back(temp.m_uvcords[(faces[i][j][1] - 1)]);
			temp2.m_Normals.push_back(temp.m_Normals[(faces[i][j][2] - 1)]);
			
		}
	}
	fclose(filein);
	return temp2;
}



And this is the drawing part of it
void Lesson02::draw()
{
	int parts = 1;

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// Clear Screen And Depth Buffer
	glLoadIdentity();					// Reset The Current Modelview Matrix
	
	glTranslatef(transX, 0.0f,transY);
	glRotatef(rotx, 0.0f, 1.0f, 0.0f);
	//Now we need to tell OpenGL to use the arrays we filled with data
	glEnableClientState(GL_VERTEX_ARRAY);   //We want a vertex array
	//glEnableClientState(GL_COLOR_ARRAY);    //and a color array
	glEnableClientState(GL_NORMAL_ARRAY);    //and a color array
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);    //and a color array

	for(int i = 0; i < parts; i++)
	{
		glBindTexture( GL_TEXTURE_2D, m_parts[i].tex_2d );
		glVertexPointer(3, GL_FLOAT, 0, &m_parts[i].m_Vertices[0]);   
		glNormalPointer(GL_FLOAT, 0, &m_parts[i].m_Normals[0]);  
		
		//glColorPointer(3, GL_FLOAT, 0, &m_parts[i].m_Colors[0]);      
		glTexCoordPointer(2, GL_FLOAT, 0, &m_parts[i].m_uvcords[0]);
		glDrawArrays(GL_POLYGON, 0, m_parts[i].vertices); 
	}

	
	rotx += 0.05f;

	//glBindTexture(GL_TEXTURE_2D, tex_2d);

	//Disable using the Vertex and Color array
	//glDisableClientState(GL_COLOR_ARRAY);
	glDisableClientState(GL_VERTEX_ARRAY);
	glDisableClientState(GL_NORMAL_ARRAY);
	glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}



I originally had the program so it would return "temp" from readFile and not "temp2" but that made it display a garbled mess of triangles, so now it returns temp 2 so that it is only drawing the face parts. It looks a lot better than what it did, but it's still not displaying the whole model. Here's the model:
# Created with Anim8or 0.95
# Object "object01":
# ComRec:

# ComRec:
#g mesh01
No. points 20:
v 0 0 12.7985
v 8.53229 0 9.53939
v -4.26615 7.38918 9.53939
v -4.26615 -7.38918 9.53939
v 9.53939 7.38918 4.26615
v 9.53939 -7.38918 4.26615
v -11.1689 4.5667 4.26615
v 1.62952 11.956 4.26615
v 1.62952 -11.956 4.26615
v -11.1689 -4.56677 4.26615
v 11.1689 4.56677 -4.26615
v 11.1689 -4.56677 -4.26615
v -9.53939 7.38918 -4.26615
v -1.62952 11.956 -4.26615
v -1.62952 -11.956 -4.26615
v -9.53939 -7.38918 -4.26615
v 4.26615 7.38918 -9.53939
v 4.26615 -7.38918 -9.53939
v -8.53229 0 -9.53939
v 0 0 -12.7985

No. normals 72:
vn 0.30353 0.52573 0.79465
vn -0.60706 0 0.79465
vn 0.30353 -0.52573 0.79465
vn 0.98225 0 0.18759
vn -0.49112 0.85065 0.18759
vn -0.49112 -0.85065 0.18759
vn 0.49112 0.85065 -0.18759
vn 0.49112 -0.85065 -0.18759
vn -0.98225 0 -0.18759
vn 0.60707 0 -0.79465
vn -0.30353 0.52574 -0.79465
vn -0.30353 -0.52574 -0.79465
vn 0.30353 0.52573 0.79465
vn 0.30353 -0.52573 0.79465
vn -0.60706 0 0.79465
vn 0.30353 0.52573 0.79465
vn 0.98225 0 0.18759
vn 0.30353 -0.52573 0.79465
vn 0.30353 0.52573 0.79465
vn -0.49112 0.85065 0.18759
vn -0.60706 0 0.79465
vn -0.60706 0 0.79465
vn -0.49112 -0.85065 0.18759
vn 0.30353 -0.52573 0.79465
vn 0.30353 0.52573 0.79465
vn 0.49112 0.85065 -0.18759
vn 0.98225 0 0.18759
vn 0.30353 -0.52573 0.79465
vn 0.49112 -0.85065 -0.18759
vn 0.98225 0 0.18759
vn -0.60706 0 0.79465
vn -0.98225 0 -0.18759
vn -0.49112 0.85065 0.18759
vn 0.30353 0.52573 0.79465
vn 0.49112 0.85065 -0.18759
vn -0.49112 0.85065 0.18759
vn 0.30353 -0.52573 0.79465
vn 0.49112 -0.85065 -0.18759
vn -0.49112 -0.85065 0.18759
vn -0.60706 0 0.79465
vn -0.98225 0 -0.18759
vn -0.49112 -0.85065 0.18759
vn 0.98225 0 0.18759
vn 0.60707 0 -0.79465
vn 0.49112 0.85065 -0.18759
vn 0.98225 0 0.18759
vn 0.60707 0 -0.79465
vn 0.49112 -0.85065 -0.18759
vn -0.49112 0.85065 0.18759
vn -0.30353 0.52574 -0.79465
vn -0.98225 0 -0.18759
vn -0.49112 0.85065 0.18759
vn -0.30353 0.52574 -0.79465
vn 0.49112 0.85065 -0.18759
vn -0.49112 -0.85065 0.18759
vn -0.30353 -0.52574 -0.79465
vn 0.49112 -0.85065 -0.18759
vn -0.49112 -0.85065 0.18759
vn -0.30353 -0.52574 -0.79465
vn -0.98225 0 -0.18759
vn 0.49112 0.85065 -0.18759
vn -0.30353 0.52574 -0.79465
vn 0.60707 0 -0.79465
vn 0.49112 -0.85065 -0.18759
vn -0.30353 -0.52574 -0.79465
vn 0.60707 0 -0.79465
vn -0.98225 0 -0.18759
vn -0.30353 -0.52574 -0.79465
vn -0.30353 0.52574 -0.79465
vn 0.60707 0 -0.79465
vn -0.30353 -0.52574 -0.79465
vn -0.30353 0.52574 -0.79465

No. texture coordinates 20:
vt 0.30902 0.80902
vt 0.57295 1
vt 0.92705 0.80902
vt 0.88197 0.50000
vt 0.50000 0.50000
vt 0.30902 0.19098
vt 0 0.30902
vt 0 0.69098
vt 0.92705 0.19098
vt 0.57295 0
vt 1 0.69098
vt 1 0.30902
vt 0.07295 0.80902
vt 0.42705 1
vt 0.42705 0
vt 0.07295 0.19098
vt 0.69098 0.80902
vt 0.69098 0.19098
vt 0.11803 0.50000
vt 0.50000 0.50000

No. faces 12:
f 1/5/13 2/4/16 5/3/25 8/2/34 3/1/19
f 1/5/15 3/1/21 7/8/31 10/7/40 4/6/22
f 1/5/14 4/6/24 9/10/37 6/9/28 2/4/18
f 2/4/17 6/9/30 12/12/46 11/11/43 5/3/27
f 3/1/20 8/2/36 14/14/52 13/13/49 7/8/33
f 4/6/23 10/7/42 16/16/58 15/15/55 9/10/39
f 5/3/26 11/11/45 17/17/61 14/14/54 8/2/35
f 6/9/29 9/10/38 15/15/57 18/18/64 12/12/48
f 7/8/32 13/13/51 19/19/67 16/16/60 10/7/41
f 11/11/44 12/12/47 18/18/66 20/20/70 17/17/63
f 13/13/50 14/14/53 17/17/62 20/20/72 19/19/69
f 15/15/56 16/16/59 19/19/68 20/20/71 18/18/65



Please help me figure out whats wrong. I'm nearly at my wits end with this. Thank you for your help in advance.

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Quote:
Original post by Robo-Link
However, I am currently trying to load a .obj file created from Animator, and it's not working right.
Your major problem is that your .obj file contains quads, not triangles. Check and see if Anim8or has an option to trianglulate meshes on export.

Quote:
			~part()
{
this->m_Vertices.clear();
// this->m_Colors.clear();
this->m_uvcords.clear();
this->m_Normals.clear();
this->tex_2d = NULL;
this->vertices = 0;

}
Two stylistic comments:
  • There is no need to clear() a std::vector in your destructor, as the vector does that itself in its own destructor.
  • You only need to use the this-> syntax for accessing member variables if the member variable has the same name as a function parameter, otherwise the compiler will deduce the this-> automatically.

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Okay, I am not able to find any way to triangulate meshs on anim8or. I am currently looking for a model development program that can. I also tried changing GL_POLYGON to GL_QUADS and it looked even worse. I tried that with both temp and temp2. Also the model is actually one of those hexigon ball things. It looked to me like it'd have 5/6 point faces, and not quads. Am I missing something?

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Okay, I am now using Blender as my 3D modeler. I have created a triangulated mesh that is a .obj file (a simple block) and when I run that and return temp I get 2 random triangles, but when I return temp2 I get 1 of the 6 faces. The only change I made to the code above is that my faces array is now a [12][3][3], and other changes to reflect that. Anyway, I still have no idea how to make this thing load properly. Please help.

Here is the new .obj file

# Blender3D v248 OBJ File:
# www.blender3d.org

No. points 8:

v 1.000000 -1.000000 -1.000000
v 1.000000 -1.000000 1.000000
v -1.000000 -1.000000 1.000000
v -1.000000 -1.000000 -1.000000
v 1.000000 1.000000 -1.000000
v 0.999999 1.000000 1.000001
v -1.000000 1.000000 1.000000
v -1.000000 1.000000 -1.000000

No. normals 8:

vn 0.000000 0.000000 -1.000000
vn -1.000000 -0.000000 -0.000000
vn -0.000000 -0.000000 1.000000
vn -0.000001 0.000000 1.000000
vn 1.000000 -0.000000 0.000000
vn 1.000000 0.000000 0.000001
vn 0.000000 1.000000 -0.000000
vn -0.000000 -1.000000 0.000000

No. texture coordinates 4:
vt 0.000000 0.000000
vt 1.000000 0.000000
vt 1.000000 1.000000
vt 0.000000 1.000000

No. faces 12:
f 5/1/1 1/2/1 4/3/1
f 5/1/1 4/3/1 8/4/1
f 3/1/2 7/2/2 8/3/2
f 3/1/2 8/3/2 4/4/2
f 2/1/3 6/2/3 3/4/3
f 6/2/4 7/3/4 3/4/4
f 1/1/5 5/2/5 2/4/5
f 5/2/6 6/3/6 2/4/6
f 5/1/7 8/2/7 6/4/7
f 8/2/7 7/3/7 6/4/7
f 1/1/8 2/2/8 3/3/8
f 1/1/8 3/3/8 4/4/8

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Doesn't the OBJ spec (such as it is...) restrict n>3-gons to be coplanar and convex? In which case you can triangulate them by pretending they're a triangle fan and making a triangle using the 0-1-2, 0-2-3, 0-3-4, etc. vertices.

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I recently made my own opengl obj renderer, and GenPFault is right.
If there are more than 3 face elements, construct new triangles by treating the faces as a triangle fan.

ex:
f 4 3 2 1 5

new f = 4 3 2 4 2 1 4 1 5

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      I'm trying to learn OpenGL through a website and have proceeded until this page of it. The output is a simple triangle. The problem is the complexity.
      I have read that page several times and tried to analyse the code but I haven't understood the code properly and completely yet. This is the code:
       
      #include <glad/glad.h> #include <GLFW/glfw3.h> #include <C:\Users\Abbasi\Desktop\std_lib_facilities_4.h> using namespace std; //****************************************************************************** void framebuffer_size_callback(GLFWwindow* window, int width, int height); void processInput(GLFWwindow *window); // settings const unsigned int SCR_WIDTH = 800; const unsigned int SCR_HEIGHT = 600; const char *vertexShaderSource = "#version 330 core\n" "layout (location = 0) in vec3 aPos;\n" "void main()\n" "{\n" " gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n" "}\0"; const char *fragmentShaderSource = "#version 330 core\n" "out vec4 FragColor;\n" "void main()\n" "{\n" " FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n" "}\n\0"; //******************************* int main() { // glfw: initialize and configure // ------------------------------ glfwInit(); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // glfw window creation GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "My First Triangle", nullptr, nullptr); if (window == nullptr) { cout << "Failed to create GLFW window" << endl; glfwTerminate(); return -1; } glfwMakeContextCurrent(window); glfwSetFramebufferSizeCallback(window, framebuffer_size_callback); // glad: load all OpenGL function pointers if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { cout << "Failed to initialize GLAD" << endl; return -1; } // build and compile our shader program // vertex shader int vertexShader = glCreateShader(GL_VERTEX_SHADER); glShaderSource(vertexShader, 1, &vertexShaderSource, nullptr); glCompileShader(vertexShader); // check for shader compile errors int success; char infoLog[512]; glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success); if (!success) { glGetShaderInfoLog(vertexShader, 512, nullptr, infoLog); cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << endl; } // fragment shader int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER); glShaderSource(fragmentShader, 1, &fragmentShaderSource, nullptr); glCompileShader(fragmentShader); // check for shader compile errors glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success); if (!success) { glGetShaderInfoLog(fragmentShader, 512, nullptr, infoLog); cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << endl; } // link shaders int shaderProgram = glCreateProgram(); glAttachShader(shaderProgram, vertexShader); glAttachShader(shaderProgram, fragmentShader); glLinkProgram(shaderProgram); // check for linking errors glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success); if (!success) { glGetProgramInfoLog(shaderProgram, 512, nullptr, infoLog); cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << endl; } glDeleteShader(vertexShader); glDeleteShader(fragmentShader); // set up vertex data (and buffer(s)) and configure vertex attributes float vertices[] = { -0.5f, -0.5f, 0.0f, // left 0.5f, -0.5f, 0.0f, // right 0.0f, 0.5f, 0.0f // top }; unsigned int VBO, VAO; glGenVertexArrays(1, &VAO); glGenBuffers(1, &VBO); // bind the Vertex Array Object first, then bind and set vertex buffer(s), //and then configure vertex attributes(s). glBindVertexArray(VAO); glBindBuffer(GL_ARRAY_BUFFER, VBO); glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0); glEnableVertexAttribArray(0); // note that this is allowed, the call to glVertexAttribPointer registered VBO // as the vertex attribute's bound vertex buffer object so afterwards we can safely unbind glBindBuffer(GL_ARRAY_BUFFER, 0); // You can unbind the VAO afterwards so other VAO calls won't accidentally // modify this VAO, but this rarely happens. Modifying other // VAOs requires a call to glBindVertexArray anyways so we generally don't unbind // VAOs (nor VBOs) when it's not directly necessary. glBindVertexArray(0); // uncomment this call to draw in wireframe polygons. //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); // render loop while (!glfwWindowShouldClose(window)) { // input // ----- processInput(window); // render // ------ glClearColor(0.2f, 0.3f, 0.3f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); // draw our first triangle glUseProgram(shaderProgram); glBindVertexArray(VAO); // seeing as we only have a single VAO there's no need to // bind it every time, but we'll do so to keep things a bit more organized glDrawArrays(GL_TRIANGLES, 0, 3); // glBindVertexArray(0); // no need to unbind it every time // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.) glfwSwapBuffers(window); glfwPollEvents(); } // optional: de-allocate all resources once they've outlived their purpose: glDeleteVertexArrays(1, &VAO); glDeleteBuffers(1, &VBO); // glfw: terminate, clearing all previously allocated GLFW resources. glfwTerminate(); return 0; } //************************************************** // process all input: query GLFW whether relevant keys are pressed/released // this frame and react accordingly void processInput(GLFWwindow *window) { if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) glfwSetWindowShouldClose(window, true); } //******************************************************************** // glfw: whenever the window size changed (by OS or user resize) this callback function executes void framebuffer_size_callback(GLFWwindow* window, int width, int height) { // make sure the viewport matches the new window dimensions; note that width and // height will be significantly larger than specified on retina displays. glViewport(0, 0, width, height); } As you see, about 200 lines of complicated code only for a simple triangle. 
      I don't know what parts are necessary for that output. And also, what the correct order of instructions for such an output or programs is, generally. That start point is too complex for a beginner of OpenGL like me and I don't know how to make the issue solved. What are your ideas please? What is the way to figure both the code and the whole program out correctly please?
      I wish I'd read a reference that would teach me OpenGL through a step-by-step method. 
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