Sphere code not working

This is a discussion on Sphere code not working within the Game Programming forums, part of the General Programming Boards category; For some odd reason my sphere generation code is not working. I wish I had 3D studio max so I ...

  1. #1
    Super Moderator VirtualAce's Avatar
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    9,596

    Sphere code not working

    For some odd reason my sphere generation code is not working. I wish I had 3D studio max so I could just create texture coordinates and the sphere at once and not worry about doing it mathematically. But until then I must generate it on my own.

    Here is the code. Please do not respond if you do not understand this code. I need the indexes and vertexes checked. It's probably something simple I'm overlooking.

    Code:
    #include "CSkySphere.h"
    #include "d:\vc6gamelibs\3dlibs\engine\d3dUtility.h"
     
    const DWORD SkySphereVertex::FVF=D3DFVF_XYZ | D3DFVF_NORMAL | D3DFVF_TEX1;
     
    #define PI			3.14159
    #define DEGTORAD(x) ((float)x*PI/180.0f)
     
    void CSkySphere::Create(IDirect3DDevice9 *device,float radius,unsigned long faces)
    {
    //Radius of sphere
    Radius=radius;
    //Number of facets - or faces per 360 degrees on x and y
    Facets=faces;
     
    //Pointer to device - IDirect3DDevice9
    Device=device;
     
    //Angle increment for sphere to have correct number of faces
    float angleinc=360.0f/faces;
     
    //x and y angles
    float alpha=0.0f;
    float beta=-90.0f;
    int vertexnum=0;
     
    //Each row and column have 1 extra vertex
    NumVertexes=(faces+1)*(faces+1);
     
    //Compute number of faces and number of tri's or primitives
    NumFaces=(faces*faces);
    NumTris=NumFaces*2;
     
    //New coordinates of vertex after spherical change
    float newx,newy,newz=0.0f;
     
    //Current u and v texture coordinates
    float cur_u=0.0f;
    float cur_v=0.0f;
     
    //Texture increment for number of faces in a 1024x1024 bitmap
    float textureinc=1024.0f/faces;
     
    //Create the vertex buffer
    Device->CreateVertexBuffer(NumVertexes*sizeof(SkySphereVertex),
    							 D3DUSAGE_WRITEONLY,
    							 SkySphereVertex::FVF,
    							 D3DPOOL_MANAGED,
    							 &VB,
    							 0);
     
    //Lock it for writing
    SkySphereVertex *Vertexes;
    VB->Lock(0,0,(void **)&Vertexes,0);
     
     
    //Sphere generation code
    do
    {
    	do
    	{
    	 //Equation of a sphere - spherical coordinates
    	 newx=cos(DEGTORAD(alpha))*sin(DEGTORAD(beta))*Radius;
    	 newy=sin(DEGTORAD(alpha))*sin(DEGTORAD(beta))*Radius;
    	 newz=cos(DEGTORAD(beta))*Radius;
    	 
    	 //Compute normalized u and v
    	 float u=cur_u/1024.0f;
    	 float v=cur_v/1024.0f;
    	 
    	 //Save vertex in buffer
    	 Vertexes[vertexnum]=SkySphereVertex(newx,newy,newz,u,v);
    	 
    	 //Move to next vertex
    	 vertexnum++;
    	 
    	 //Increment texture u coord accordingly
    	 cur_u+=textureinc;
    	 
    	 //Increment y angle
    	 beta+=angleinc;
    	} while (beta<=90.0f);
     
    	//To account for last vertex on row
    	vertexnum++;
     
    	//Reset y angle to top of sphere
    	beta=-90.0f;
    	
    	//Increase X angle - longitude
    	alpha+=angleinc;
     
    	//Reset texture u coord
    	cur_u=0.0f;
      
    	//Increment current v texture coord accordingly 
    	cur_v+=textureinc;
    } while (alpha<=360.0f);
     
    //Unlock vertex buffer
    VB->Unlock();
     
    //Lock index buffer and create it 
    WORD *indices=0;
     
    //6 indexes per face - 1 textured quad=2 tris=6 indexes
    WORD numindices=NumFaces*6;
    Device->CreateIndexBuffer(NumFaces*sizeof(WORD),
    							D3DUSAGE_WRITEONLY,
    							D3DFMT_INDEX16,
    							D3DPOOL_MANAGED,
    							&IB,0);
    IB->Lock(0,0,(void **)&indices,0);
     
    int curvertex=0;
     
    //Generate indexes for tris
    for (int i=0;i<(numindices-6);i+=6)
    {
     
    	//First tri
    	indices[i] =	 curvertex;
    	indices[i+1]=	 curvertex+1;
    	indices[i+2]=	 curvertex+faces;
    	//Second tri
    	indices[i+3]=	 curvertex+faces;
    	indices[i+4]=	 curvertex+1;
    	indices[i+5]=	 curvertex+faces+1;
    	curvertex++;
    }
     
    //Unlock buffer
    IB->Unlock();
     
    }
     
    void CSkySphere::Render(D3DXVECTOR3 &PlayerPos)
    {
    //Translate sphere to always be centered around camera location
    D3DXMATRIX trans;
    D3DXMatrixTranslation(&trans,PlayerPos.x,PlayerPos.y,PlayerPos.z);
    Device->SetTransform(D3DTS_WORLD,&trans);
     
    //Set cull mode to none for testing - later will be D3DCULL_CW
    //since camera is inside of the sphere thus reversing winding order
    Device->SetRenderState(D3DRS_CULLMODE,D3DCULL_NONE);
     
    //Set texture to our current backdrop texture 
    Device->SetTexture(0,Backdrop);
     
    //Set material for sphere
    D3DMATERIAL9 mtrl;
    mtrl.Ambient=d3d::RED*.8f;
    mtrl.Diffuse=d3d::WHITE*.8f;
    mtrl.Specular=d3d::WHITE*.2f;
    mtrl.Emissive=d3d::BLACK;
    mtrl.Power=4.0f;
    Device->SetMaterial(&mtrl);
     
    //Set stream source, index buffer, and FVF
    Device->SetStreamSource(0,VB,0,sizeof(SkySphereVertex));
    Device->SetIndices(IB);
    Device->SetFVF(SkySphereVertex::FVF);
     
    //Draw the thing
    Device->DrawIndexedPrimitive(D3DPT_TRIANGLELIST,0,0,
    								NumVertexes,0,NumTris);
     
    //Set cull mode back to counter-clockwise winding order
    Device->SetRenderState(D3DRS_CULLMODE,D3DCULL_CCW);
    }
    Last edited by VirtualAce; 09-23-2004 at 02:37 AM.

  2. #2
    VA National Guard The Brain's Avatar
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    Manassas, VA USA
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    hmm.. looks very spherical...
    • "Problem Solving C++, The Object of Programming" -Walter Savitch
    • "Data Structures and Other Objects using C++" -Walter Savitch
    • "Assembly Language for Intel-Based Computers" -Kip Irvine
    • "Programming Windows, 5th edition" -Charles Petzold
    • "Visual C++ MFC Programming by Example" -John E. Swanke
    • "Network Programming Windows" -Jones/Ohlund
    • "Sams Teach Yourself Game Programming in 24 Hours" -Michael Morrison
    • "Mathmatics for 3D Game Programming & Computer Graphics" -Eric Lengyel

  3. #3
    Super Moderator VirtualAce's Avatar
    Join Date
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    What? I already figured it out - check the 3D sphere backdrop problem thread.

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