I wrote a custom OBJ file importer which worked fairly well however was not robust enough to support everything. I've decided to give AssImp a shot. I followed some tutorials and have set up my code to read in the vertices, tex coords, normals, and indices of an OBJ cube model that I have had success loading with my custom importer. The cube model's faces do not render properly, instead only rendering a few tri's of the cube. The way AssImp handles the data is obviously a bit different than my solution because the normals, positions/vertices, tex coords, and indices do not match my custom solution. I would very much appreciate some insight into why I'm having issues as all of the tutorials I've found have matched my approach. If a picture of the faulty rendered cube would be helpful I can work on getting a screenshot up. Thank you.
My Asset importing class is at:
http://codebin.org/view/4d2ec4d3
The rest of my code is at (Mesh Class is in source/graphics):
https://github.com/BennetLeff/PhySim

On Friday, 6 March 2015 at 02:41:19 UTC, Bennet wrote:
> I wrote a custom OBJ file importer which worked fairly well however was not robust enough to support everything. I've decided to give AssImp a shot. I followed some tutorials and have set up my code to read in the vertices, tex coords, normals, and indices of an OBJ cube model that I have had success loading with my custom importer. The cube model's faces do not render properly, instead only rendering a few tri's of the cube. The way AssImp handles the data is obviously a bit different than my solution because the normals, positions/vertices, tex coords, and indices do not match my custom solution. I would very much appreciate some insight into why I'm having issues as all of the tutorials I've found have matched my approach. If a picture of the faulty rendered cube would be helpful I can work on getting a screenshot up. Thank you.
> My Asset importing class is at:
> http://codebin.org/view/4d2ec4d3
> The rest of my code is at (Mesh Class is in source/graphics):
> https://github.com/BennetLeff/PhySim

There are some issues with your loadMesh code:

    numVerts = mesh.mNumFaces * 3;

The number of vertices is independent if the number of faces. What you're calculating here is the number of indices, which is indeed guaranteed to be three times the number of faces since you're asking for triangulation when loading the scene. The number of vertices is simply:
    mesh.mNumVertices
And this value should be used as size for the vertex, normal, and texture coordinate arrays.

Then you'll need two separate loops to load the vertices and indices. Loading the vertices is simply looping through all vertex arrays of the source mesh and copying them to your vertex arrays.

To load the indices you need to loop through all faces in the source mesh, and then add the face indices to your index buffer. Something like this:
foreach(faceIndex; 0 .. mash.mNumFaces)
{
  auto face = mesh.mFaces[faceIndex];
  foreach(i; 0 .. 3)
    indices[faceIndex*3 + i] = face.mIndices[i];
}

On Saturday, 7 March 2015 at 13:11:22 UTC, Rene Zwanenburg wrote:
> On Friday, 6 March 2015 at 02:41:19 UTC, Bennet wrote:
>> I wrote a custom OBJ file importer which worked fairly well however was not robust enough to support everything. I've decided to give AssImp a shot. I followed some tutorials and have set up my code to read in the vertices, tex coords, normals, and indices of an OBJ cube model that I have had success loading with my custom importer. The cube model's faces do not render properly, instead only rendering a few tri's of the cube. The way AssImp handles the data is obviously a bit different than my solution because the normals, positions/vertices, tex coords, and indices do not match my custom solution. I would very much appreciate some insight into why I'm having issues as all of the tutorials I've found have matched my approach. If a picture of the faulty rendered cube would be helpful I can work on getting a screenshot up. Thank you.
>> My Asset importing class is at:
>> http://codebin.org/view/4d2ec4d3
>> The rest of my code is at (Mesh Class is in source/graphics):
>> https://github.com/BennetLeff/PhySim
>
> There are some issues with your loadMesh code:
>
>     numVerts = mesh.mNumFaces * 3;
>
> The number of vertices is independent if the number of faces. What you're calculating here is the number of indices, which is indeed guaranteed to be three times the number of faces since you're asking for triangulation when loading the scene. The number of vertices is simply:
>     mesh.mNumVertices
> And this value should be used as size for the vertex, normal, and texture coordinate arrays.
>
> Then you'll need two separate loops to load the vertices and indices. Loading the vertices is simply looping through all vertex arrays of the source mesh and copying them to your vertex arrays.
>
> To load the indices you need to loop through all faces in the source mesh, and then add the face indices to your index buffer. Something like this:
> foreach(faceIndex; 0 .. mash.mNumFaces)
> {
>   auto face = mesh.mFaces[faceIndex];
>   foreach(i; 0 .. 3)
>     indices[faceIndex*3 + i] = face.mIndices[i];
> }

I've made that edit but I'm getting lots of "nan" in my array of vertices, textures coordinates and normals. Here's a screenshot: http://imgur.com/lXDxFJM

On Saturday, 7 March 2015 at 21:19:47 UTC, Bennet wrote:
> On Saturday, 7 March 2015 at 13:11:22 UTC, Rene Zwanenburg wrote:
>> On Friday, 6 March 2015 at 02:41:19 UTC, Bennet wrote:
>>> I wrote a custom OBJ file importer which worked fairly well however was not robust enough to support everything. I've decided to give AssImp a shot. I followed some tutorials and have set up my code to read in the vertices, tex coords, normals, and indices of an OBJ cube model that I have had success loading with my custom importer. The cube model's faces do not render properly, instead only rendering a few tri's of the cube. The way AssImp handles the data is obviously a bit different than my solution because the normals, positions/vertices, tex coords, and indices do not match my custom solution. I would very much appreciate some insight into why I'm having issues as all of the tutorials I've found have matched my approach. If a picture of the faulty rendered cube would be helpful I can work on getting a screenshot up. Thank you.
>>> My Asset importing class is at:
>>> http://codebin.org/view/4d2ec4d3
>>> The rest of my code is at (Mesh Class is in source/graphics):
>>> https://github.com/BennetLeff/PhySim
>>
>> There are some issues with your loadMesh code:
>>
>>    numVerts = mesh.mNumFaces * 3;
>>
>> The number of vertices is independent if the number of faces. What you're calculating here is the number of indices, which is indeed guaranteed to be three times the number of faces since you're asking for triangulation when loading the scene. The number of vertices is simply:
>>    mesh.mNumVertices
>> And this value should be used as size for the vertex, normal, and texture coordinate arrays.
>>
>> Then you'll need two separate loops to load the vertices and indices. Loading the vertices is simply looping through all vertex arrays of the source mesh and copying them to your vertex arrays.
>>
>> To load the indices you need to loop through all faces in the source mesh, and then add the face indices to your index buffer. Something like this:
>> foreach(faceIndex; 0 .. mash.mNumFaces)
>> {
>>  auto face = mesh.mFaces[faceIndex];
>>  foreach(i; 0 .. 3)
>>    indices[faceIndex*3 + i] = face.mIndices[i];
>> }
>
> I've made that edit but I'm getting lots of "nan" in my array of vertices, textures coordinates and normals. Here's a screenshot: http://imgur.com/lXDxFJM

Update: I've gotten the vertices, normals an uvs to load into arrays properly, now I just can't get the indices loaded. I'm loading them in the manner you suggested but they only load up to index 22 when there are 33 vertices. I imagine there should be indices ranging from 0-33 loaded into the array not 0-22. However there are 33 indices loaded.

On Saturday, 7 March 2015 at 22:01:26 UTC, Bennet wrote:
> Update: I've gotten the vertices, normals an uvs to load into arrays properly, now I just can't get the indices loaded. I'm loading them in the manner you suggested but they only load up to index 22 when there are 33 vertices. I imagine there should be indices ranging from 0-33 loaded into the array not 0-22. However there are 33 indices loaded.

Are you sure about that? Your earlier screenshot shows only 23 vertices..

On Friday, 6 March 2015 at 02:41:19 UTC, Bennet wrote:
> I wrote a custom OBJ file importer which worked fairly well however was not robust enough to support everything. I've decided to give AssImp a shot. I followed some tutorials and have set up my code to read in the vertices, tex coords, normals, and indices of an OBJ cube model that I have had success loading with my custom importer. The cube model's faces do not render properly, instead only rendering a few tri's of the cube. The way AssImp handles the data is obviously a bit different than my solution because the normals, positions/vertices, tex coords, and indices do not match my custom solution. I would very much appreciate some insight into why I'm having issues as all of the tutorials I've found have matched my approach. If a picture of the faulty rendered cube would be helpful I can work on getting a screenshot up. Thank you.
> My Asset importing class is at:
> http://codebin.org/view/4d2ec4d3
> The rest of my code is at (Mesh Class is in source/graphics):
> https://github.com/BennetLeff/PhySim

Imagine a square mesh made up of two triangles, the un-indexed version has 6 vertices, but the indexed version that you would be using has 4 vertices because a side is shared by the two triangles (which is managed by the index array). This is why you can't assume each face has 3 vertices.

I have been trying to learn opengl and D recently together and this is the simple code I have been using to load models from assimp.

for(int i = 0; i < mesh.mNumVertices; i++)
		{
			aiVector3D vert = mesh.mVertices[i];
			verts ~= vec3(vert.x, vert.y, vert.z);

			aiVector3D uvw = mesh.mTextureCoords[0][i];
			uvs ~= vec2(uvw.x, uvw.y);
		
			aiVector3D n = mesh.mNormals[i];
			normals ~= vec3(n.x, n.y, n.z);
		}

		
		for(int i = 0; i < mesh.mNumFaces; i++)
		{
			const aiFace face = mesh.mFaces[i];
			
			indices ~= face.mIndices[0];
			indices ~= face.mIndices[1];
			indices ~= face.mIndices[2];
			
		}

On Monday, 9 March 2015 at 14:25:54 UTC, Michael Robertson wrote:
> On Friday, 6 March 2015 at 02:41:19 UTC, Bennet wrote:
>> I wrote a custom OBJ file importer which worked fairly well however was not robust enough to support everything. I've decided to give AssImp a shot. I followed some tutorials and have set up my code to read in the vertices, tex coords, normals, and indices of an OBJ cube model that I have had success loading with my custom importer. The cube model's faces do not render properly, instead only rendering a few tri's of the cube. The way AssImp handles the data is obviously a bit different than my solution because the normals, positions/vertices, tex coords, and indices do not match my custom solution. I would very much appreciate some insight into why I'm having issues as all of the tutorials I've found have matched my approach. If a picture of the faulty rendered cube would be helpful I can work on getting a screenshot up. Thank you.
>> My Asset importing class is at:
>> http://codebin.org/view/4d2ec4d3
>> The rest of my code is at (Mesh Class is in source/graphics):
>> https://github.com/BennetLeff/PhySim
>
> Imagine a square mesh made up of two triangles, the un-indexed version has 6 vertices, but the indexed version that you would be using has 4 vertices because a side is shared by the two triangles (which is managed by the index array). This is why you can't assume each face has 3 vertices.
>
> I have been trying to learn opengl and D recently together and this is the simple code I have been using to load models from assimp.
>
> for(int i = 0; i < mesh.mNumVertices; i++)
> 		{
> 			aiVector3D vert = mesh.mVertices[i];
> 			verts ~= vec3(vert.x, vert.y, vert.z);
>
> 			aiVector3D uvw = mesh.mTextureCoords[0][i];
> 			uvs ~= vec2(uvw.x, uvw.y);
> 		
> 			aiVector3D n = mesh.mNormals[i];
> 			normals ~= vec3(n.x, n.y, n.z);
> 		}
>
> 		
> 		for(int i = 0; i < mesh.mNumFaces; i++)
> 		{
> 			const aiFace face = mesh.mFaces[i];
> 			
> 			indices ~= face.mIndices[0];
> 			indices ~= face.mIndices[1];
> 			indices ~= face.mIndices[2];
> 			
> 		}

My code roughly matches yours at this point however I get a weird bug with only my cube model where the top face and one of the side tri's are not rendered. However it seems to work fine with a model of a pitcher and a model of a monkey.