Hi I have a weird bug. I recently started using DirectX9 in visual studio C++. Thus far I have managed to load and display meshes from *.x files. The problem is: when I load in more than 1 model and wish to translate/rotate only one of the models all the models loaded are transformed. Basically what I want to do is load a room (which would be one model), and then use a different model to move around the room. I am using: D3DXMatrixRotationX, D3DXMatrixRotationY, D3DXMatrixRotationZ, and D3DXMatrixTranslation to transform a giving model. I think the problem is because the LPDIRECT3DDEVICE9 is used to load both the models and the same LPDIRECT3DDEVICE9 is used to transform the models. I don't know how to tell LPDIRECT3DDEVICE9 (or whatever I need to tell) to transform the models independently. I'm not using DXUT cuz I wanna know how to load and move object manually. Here is some code thus far, it might be to much code but I wanna define/show what I am doing and how I am doing it. I omitted some of the code cuz it gets to long. ////////////////////////////////////class header file//////////////////////// class CStaticMesh { private: LPDIRECT3DDEVICE9 pd3dDevice; //device pointer //MESH data LPD3DXMESH mesh; // Our mesh object D3DMATERIAL9 *meshMaterials; LPDIRECT3DTEXTURE9 *meshTextures; DWORD numMaterials; float MeshPosRot[6]; //end MESH DATA public: CStaticMesh(LPDIRECT3DDEVICE9 DevicePTR); ~CStaticMesh(); HRESULT loadMeshFile(char *dir); HRESULT drawMeshID(); HRESULT moveMeshID(FLOAT nx=0.0f,FLOAT ny=0.0f,FLOAT nz=0.0f); HRESULT rotateMeshID(FLOAT nx=0.0f,FLOAT ny=0.0f,FLOAT nz=0.0f); }; ///////////////////////////class implementation file///////////////////// CStaticMesh::CStaticMesh(LPDIRECT3DDEVICE9 DevicePTR) { ...... pd3dDevice=DevicePTR; ...... } HRESULT CStaticMesh::loadMeshFile(char *dir) { ......... if(FAILED(D3DXLoadMeshFromX(dir, D3DXMESH_SYSTEMMEM, pd3dDevice, NULL, &materialBuffer,NULL, &numMaterials, &mesh ))) return false; ........ } HRESULT CStaticMesh::drawMeshID() { for (DWORD i=0; i<numMaterials; i++) { // Set the material and texture for this subset pd3dDevice->SetMaterial(&meshMaterials); pd3dDevice->SetTexture(0,meshTextures); // Draw the mesh subset mesh->DrawSubset( i ); } return true; } HRESULT CStaticMesh::moveMeshID(FLOAT nx,FLOAT ny,FLOAT nz) { D3DXMATRIX objMat,moveMat; pd3dDevice->GetTransform(D3DTS_WORLD, &objMat); D3DXMatrixIdentity(&moveMat); MeshPosRot[0]=nx; MeshPosRot[1]=ny; MeshPosRot[2]=nz; D3DXMatrixTranslation(&moveMat,MeshPosRot[0],MeshPosRot[1],MeshPosRot[2]); D3DXMatrixMultiply(&objMat, &objMat, &moveMat); pd3dDevice->SetTransform(D3DTS_WORLD, &objMat); return true; } HRESULT CStaticMesh::rotateMeshID(FLOAT nx,FLOAT ny,FLOAT nz) { D3DXMATRIX matRotate,finalMat,objMat; pd3dDevice->GetTransform(D3DTS_WORLD, &objMat); MeshPosRot[3]=nx;//update new rotation MeshPosRot[4]=ny; MeshPosRot[5]=nz; // Set the rotation D3DXMatrixRotationX(&matRotate, MeshPosRot[3]); D3DXMatrixMultiply(&finalMat, &objMat, &matRotate); D3DXMatrixRotationY(&matRotate, MeshPosRot[4]); D3DXMatrixMultiply(&finalMat, &finalMat, &matRotate); D3DXMatrixRotationZ(&matRotate, MeshPosRot[5]); D3DXMatrixMultiply(&finalMat, &finalMat, &matRotate); pd3dDevice->SetTransform(D3DTS_WORLD, &finalMat); return true; } //////////////////////////main file////////////////////////// CStaticMesh *cmesh; CStaticMesh *cmeshRoom; VOID render() { pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET|D3DCLEAR_ZBUFFER ,D3DCOLOR_XRGB( 0,0,0 ), 1.0f, 0 );//clear to black if( SUCCEEDED( pd3dDevice->BeginScene() ) ) { cameraStuff(); cmesh->moveMeshID(moveX,moveY,moveZ); cmesh->rotateMeshID(rotateX,rotateY,rotateZ); cmesh->drawMeshID(); cmeshRoom->drawMeshID(); pd3dDevice->EndScene(); pd3dDevice->Present(NULL,NULL,NULL,NULL); } } INT WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance,LPTSTR lpCmdLine, int nCmdShow ) { ....... cmesh=new CStaticMesh(pd3dDevice); cmeshRoom=new CStaticMesh(pd3dDevice); if(!cmesh->loadMeshFile("DwarfWithEffectInstance.x")) return false; if(!cmeshRoom->loadMeshFile("room.x")) return false; ........ render(); ........ delete cmesh; delete cmeshRoom; return (int) msg.wParam; } ///////////////////////////END//////////////////////////////// If you look at the render function: I am only moving the cmesh model and not the cmeshRoom model. But when I compile and run both models are transformed.... I hope you can help me. Thanks [Edited by - Kapoef on March 18, 2010 10:36:12 AM]

I tried your(Buckeye) approach but to no avail. When I implemented:

D3DXMATRIX oldWorld;
dev->GetTransform(D3DTS_WORLD,&oldWorld);
dev->SetTransform(D3DTS_WORLD,&thisObjectsMat); // set the transform here!
... // do the rendering
dev->SetTransfrom(D3DTS_WORLD,&oldWorld);

no transformation was done at all.

Is there a way to get access to the matrix for a specific model only. As I understand it the device in use only has one D3DTS_WORLD. But all objects loaded in are loaded using the one device thus making all the world transform relative to each other, or not?

What the code does now is:

Backup old world -> transform the model a bit -> display -> restore the old world AND the old model.

Thus the entire old world is restored and the next transformation will be voided, since the old world is continuously restored.

I guess I am missing something... but idk what thats the big question....

ok as i understand it now:

basic code flow follows:

1. INIT all
1.1. Load 2 *.x model (model A and model B).
1.2. Set D3DTS_WORLD to (0,0,0).

2. LOOP
2.1. Begin frame (using pd3dDevice->BeginScene() ).
2.2. Set new D3DTS_WORLD for model A.
2.3. Display model A. (using DrawSubset() ).
2.4. Set new D3DTS_WORLD for model B (in this case D3DTS_WORLD to (0,0,0) ).
2.5. Display model B. (using DrawSubset() ).
2.6. End frame(using pd3dDevice->EndScene() ).
2.7. display Buffer (pd3dDevice->Present(NULL,NULL,NULL,NULL) ).

k well i tried the above approach and it still does not work... The entire frame is stationary model A does not move at all.

Do any of you have a simple complete example that i could look at? this is probably a trivial problem but i fail to correct my error.

By the way thanks for the advice so far ;)

Buckeye you are my hero!!!!!!!!! IT IS ALIVE!!!

I understand where my error was now. I multiplied the matrices incorrectly. I guess I'll have to review my 3D math algebra again...

thank you thank you thank you thank you thank you thank you