• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
ekba89

Skinned mesh with Assimp

2 posts in this topic

I'm trying to load models with skinning information with assimp. I have managed to load static models but i have problems with bones. Currently I'm trying to load the famous tiny.x [img]http://public.gamedev.net//public/style_emoticons/default/smile.png[/img] but i think i'm doing something wrong with bone transformations. Lastly i didn't attach screenshots because it is just random triangles but if you want i can add it. Also before i put the code i should say the code is for tiny.x. I mean it has only 1 mesh and 35 bones in it. So i know my code won't work for other meshes but before i try to write more generalized code i wanted to understand the basics. And here is the code.

[code]AnimatedMesh* ModelLoader::LoadAnimatedModel(const char* filePath)
{
const aiScene* scene = aiImportFile(filePath, (aiProcessPreset_TargetRealtime_Quality|aiProcess_ConvertToLeftHanded) & ~aiProcess_FindInvalidData);
if(!scene)
{
return NULL;
}
AnimatedMesh* animMesh = new AnimatedMesh();
for(unsigned int i = 0; i < scene->mNumMeshes; i++)
{
aiMesh* mesh = scene->mMeshes[i];
//Copy vertex information
unsigned int numVertices = mesh->mNumVertices;
animMesh->vertexCount = numVertices;
animMesh->vertices = new AnimatedVertexType[numVertices];
for(unsigned int i_vert = 0; i_vert < numVertices; i_vert++)
{
aiVector3D vertex = mesh->mVertices[i_vert];
animMesh->vertices[i_vert].position = aiVector3toD3DVector(vertex);
}
//Copy index information
unsigned int numIndices = mesh->mNumFaces * 3;
animMesh->indexCount = numIndices;
animMesh->indices = new unsigned int[numIndices];
unsigned int indicePosition = 0;
for(unsigned int i_face = 0; i_face < mesh->mNumFaces; i_face++)
{
aiFace face = mesh->mFaces[i_face];
animMesh->indices[indicePosition++] = face.mIndices[0];
animMesh->indices[indicePosition++] = face.mIndices[1];
animMesh->indices[indicePosition++] = face.mIndices[2];
}
//Copy bone information
animMesh->boneCount = mesh->mNumBones;
std::vector<std::vector<aiVertexWeight>> weightPerVertex(mesh->mNumVertices);

for(unsigned int i_bone = 0; i_bone < mesh->mNumBones; i_bone++)
{
aiBone* b = mesh->mBones[i_bone];

for(unsigned int i_weight = 0; i_weight < b->mNumWeights; i_weight++)
{
aiVertexWeight vertexWeight = b->mWeights[i_weight];
weightPerVertex[vertexWeight.mVertexId].push_back(aiVertexWeight(i_bone, vertexWeight.mWeight));
}

aiNode* node = scene->mRootNode->FindNode(b->mName);

//Create bone transformations------------------->i think my problem is here
Bone* meshBone = new Bone();
meshBone->boneOffsetMatrix = aiMatrixtoD3DMatrix(b->mOffsetMatrix);
meshBone->localTransformMatrix = aiMatrixtoD3DMatrix(node->mTransformation);
meshBone->transformMatrix = meshBone->boneOffsetMatrix * meshBone->localTransformMatrix;
meshBone->name = node->mName.data;
node = node->mParent;
while(node)
{
meshBone->transformMatrix = aiMatrixtoD3DMatrix(node->mTransformation) * meshBone->transformMatrix;
node = node->mParent;
}
animMesh->bones.push_back(meshBone);
}
//Get weights for each vertex
for(unsigned int x = 0; x < numVertices; x++)
{
for(unsigned int y = 0; y < weightPerVertex[x].size(); y++)
{
animMesh->vertices[x].boneIndices[y] = weightPerVertex[x][y].mVertexId; // vertex id is used as bone id when creating this vector
animMesh->vertices[x].boneWeights[y] = weightPerVertex[x][y].mWeight;
}
}
for(unsigned int x = 0; x < 35; x++) //tiny.x has 35 bones
{
animMesh->boneMatrices[x] = animMesh->bones[x]->transformMatrix; //for easy use
}
}
return animMesh;
}[/code]

And shader.

[code]matrix viewMatrix;
matrix projectionMatrix;
matrix boneMatrices[35];
struct VS_In
{
float4 position : POSITION;
unsigned int4 boneIndices : BONEINDICES;
float4 boneWeights : BLENDWEIGHTS;
};
struct PS_In
{
float4 position : SV_POSITION;
};
PS_In VS_Main(VS_In vertex)
{
PS_In output = (PS_In)0;
output.position = float4(0.0f, 0.0f, 0.0f, 1.0f);
for(int i = 0; i < 4; i++)
{
output.position += vertex.boneWeights[i] * mul(vertex.position, boneMatrices[vertex.boneIndices[i]]);
}
output.position.w = 1.0f;
matrix viewProjection = mul(viewMatrix, projectionMatrix);
output.position = mul(output.position, viewProjection);
return output;
}
float4 PS_Main(PS_In frag) : SV_TARGET0
{
return float4(1.0f, 1.0f, 1.0f, 1.0f);
}
technique11 AnimatedMesh
{
pass p0
{
SetVertexShader(CompileShader(vs_5_0, VS_Main()));
SetPixelShader(CompileShader(ps_5_0, PS_Main()));
}
}[/code]

Thanks!
0

Share this post


Link to post
Share on other sites
If you have the full source of assimp library, then you can take a look into the project named "assimp_view". It shows how to load the model, animations, skin info etc. and manage them. Also it shows how to build D3DX buffers and render. Here's the path: assimp_sdk_dir\workspaces\vc9\

btw, it's written in C++ and for DX9. So I hope you can understand.

hth.
-R
0

Share this post


Link to post
Share on other sites
Thanks for the advice but I already knew that. In fact my code is based on it. But I looked through it again and found out that they were multiplying their matrices with mesh's inverse global matrix. So I have added the code below to my code.
[code]aiNode* node = scene->mRootNode->FindNode("body"); //mesh is in this node for tiny.x
D3DXMATRIX inverseTransform = aiMatrixtoD3DMatrix(node->mTransformation);
node = node->mParent;
while(node)
{
inverseTransform = aiMatrixtoD3DMatrix(node->mTransformation) * inverseTransform;
node = node->mParent;
}[/code]

And I have changed the code for calculating final matrices to this

[code]meshBone->localTransformMatrix = aiMatrixtoD3DMatrix(node->mTransformation);
meshBone->transformMatrix = meshBone->localTransformMatrix;
node = node->mParent;
while(node)
{
meshBone->transformMatrix = aiMatrixtoD3DMatrix(node->mTransformation) * meshBone->transformMatrix;
node = node->mParent;
}
meshBone->transformMatrix = inverseTransform * meshBone->transformMatrix * meshBone->boneOffsetMatrix;[/code]

But its still not working. Also I tried to just sending offset matrices to test it out and every piece of her body was in the (0,0,0) point but other than that it was fine. So I think there is nothing wrong with the shader and I think problem might be bones' transform matrices. But I couldn't find what is wrong with it. Lastly I tried every possible order for multiplication of transformMatrix but it didn't work. If anyone can tell me the correct order I appreciate it.
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0