[SOLVED]Need help rendering data parsed from a .obj file.

[Rekenaar]

Hi everyone, sorry if this has been asked already (couldn't find it).

Anyway, I've parsed all of the data from a .obj file into float arrays (for verts, normals, texture-coords, and the face data aswell)
I've checked all the data against the actual file, so I don't think my parsing is a problem, but when I try to render the object (which is a cube) I just get 2 triangles. (Below, viewed from an angle)



I'm guessing that my problem is that I'm not doing anything with the face data and am just drawing the vertices.
If that is the case, could someone show me how to draw the faces aswell?

Here's my code:

The parse function of my OBJModel class

Code:

try {
while(((currentLine = file.readLine()) != null)) {
lineCount++;
currentLine = currentLine.trim();

if(currentLine.length() > 0) {
// Vertices
if(currentLine.charAt(0) == 'v' & currentLine.charAt(1) == ' ') {
String[] vertexCoordinatesString = currentLine.split("\\s+");
for(int i = 1; i < vertexCoordinatesString.length; i++) {
vertexArrayList.add(Float.valueOf(vertexCoordinatesString[i]).floatValue());
}
}
// Normals
if(currentLine.charAt(0) == 'v' & currentLine.charAt(1) == 'n') {
String[] normalCoordinatesString = currentLine.split("\\s+");
for(int i = 1; i < normalCoordinatesString.length; i++) {
vertexNormalsArrayList.add(Float.valueOf(normalCoordinatesString[i]).floatValue());
}
}
// Texture Coordinates
if(currentLine.charAt(0) == 'v' & currentLine.charAt(1) == 't') {
String[] textureCoordinatesString = currentLine.split("\\s+");
for(int i = 1; i < textureCoordinatesString.length; i++) {
vertexTextureCoordinatesArrayList.add(Float.valueOf(textureCoordinatesString[i]).floatValue());
}
}
if(currentLine.charAt(0) == 'f' & currentLine.charAt(1) == ' ') {
String[] faceCoordinatesString = currentLine.split("\\s+");

for(int i = 1; i < faceCoordinatesString.length; i++) {
String fixstring = faceCoordinatesString[i].replaceAll("//","/0/");
String[] tempstring = fixstring.split("/");

faceArrayList.add(Float.valueOf(tempstring[0]).floatValue());
if(tempstring.length > 1) {
faceTextureCoordinatesArrayList.add(Float.valueOf(tempstring[1]).floatValue());
}
else {
faceTextureCoordinatesArrayList.add(0.0f);
}
if(tempstring.length > 2) {
faceNormalsArrayList.add(Float.valueOf(tempstring[2]).floatValue());
}
else {
faceNormalsArrayList.add(0.0f);
}
}
}
}
}
// Convert ArrayLists to float[] arrays
// Vertices
vertices = new float[vertexArrayList.size()];
for (int i = 0; i < vertexArrayList.size(); i++) {
vertices[i] = vertexArrayList.get(i);
}
vertexNormals = new float[vertexNormalsArrayList.size()];
for (int i = 0; i < vertexNormalsArrayList.size(); i++) {
vertexNormals[i] = vertexNormalsArrayList.get(i);
}
vertexTextureCoordinates = new float[vertexTextureCoordinatesArrayList.size()];
for (int i = 0; i < vertexTextureCoordinatesArrayList.size(); i++) {
vertexTextureCoordinates[i] = vertexTextureCoordinatesArrayList.get(i);
}
// Faces
faces = new float[faceArrayList.size()];
for (int i = 0; i < faceArrayList.size(); i++) {
faces[i] = faceArrayList.get(i);
}
faceNormals = new float[faceNormalsArrayList.size()];
for (int i = 0; i < faceNormalsArrayList.size(); i++) {
faceNormals[i] = faceNormalsArrayList.get(i);
}
faceTextureCoordinates = new float[faceTextureCoordinatesArrayList.size()];
for (int i = 0; i < faceTextureCoordinatesArrayList.size(); i++) {
faceTextureCoordinates[i] = faceTextureCoordinatesArrayList.get(i);
}
}

The code I use to draw the object

Code:

public void Draw(Vector3f position, Vector3f rotation, Color colour) {
GL11.glTranslatef(position.x,position.y,position.z);
GL11.glRotatef(rotation.x, 1, 0, 0);
GL11.glRotatef(rotation.y, 0, 1, 0);
GL11.glRotatef(rotation.z, 0, 0, 1);
GL11.glColor3f(colour.r, colour.g, colour.b);

GL11.glBegin(GL11.GL_TRIANGLES);
for (int i = 0; i < model.vertices.length / 3; i++) {
GL11.glVertex3f(model.vertices[0 + 3 * i],model.vertices[1 + 3 * i],model.vertices[2 + 3 * i]);
}
GL11.glEnd();
}

Thanks  
--
Daniel

[kappa]

haven't had a look at your code but there is a working obj loader in this thread which might help.

[Rekenaar]

Yeah, I actually based mine off that  
Anyway, if nothing comes of this thread I'll just use that one.

Thanks
--
Daniel

[seanrowens]

Or you could try this one;

http://darksleep.com/oobjloader/

[Rekenaar]

Oh wow, that one looks great!
I'll check that one out later today and report progress.

[Epicbo]

Take a look at this youtube tutorial: http://www.youtube.com/watch?v=izKAvSV3qk0

[seanrowens]

Cool.  I wrote it.  I'm going to work on making materials work better (currently it parses everything in materials and then ignores everything unless it's a mapKd in which cases it uses it as a texture, but very simply.)   I'm also thinking of changing the sample Builder implementation to use org.lwjgl.util.vector.Vector3f instead of the various vertex classes.  Let me know what you think.

[Rekenaar]

Yay! I managed to figure it out!
What I wasn't doing, was drawing the faces correctly (or at all for that matter).

This posted by Rraawwrr really helped me out.

The rows that start with f are position/UV index pairs.

So, the 1/1 line refers to position at index 1 (v 0.084387 1.041998 1.380985) and texture coordinate (vt 0.000000 0.000000).

Note also that obj files are indexed starting from 1.

Here is the updated rendering code:

Code:

GL11.glBegin(GL11.GL_TRIANGLES);
for(int i = 0; i < model.faces.length; i++) {
GL11.glVertex3f(model.vertices[((model.faces[i] - 1) * 3)], model.vertices[((model.faces[i] - 1) * 3) + 1], model.vertices[((model.faces[i] - 1) * 3) + 2]);
}
GL11.glEnd();

Thanks for all the help everyone
--
Daniel