   point sprites not visible
  I am using the "Tutorial 17: Point Sprites" from http://www.riaz.de/tutorials/d3d17/d3d17.html to create a ship engine. The sprite is rendered to my desired position and color, but sometimes when I rotate the camera the sprite is not rendered althow there is no other object in front of it. Has someone have any idea why is this happening ?-- Create Codevoid*pData;D3DVERTEXpoint[] = { {-0.5f,0.866f,0.0f,10000.21f,0xff0000ff} };mDevice->CreateVertexBuffer( sizeof(point), D3DUSAGE_POINTS | D3DUSAGE_WRITEONLY,D3DFVF_CUSTOMVERTEX,D3DPOOL_MANAGED,&mSpriteVB,NULL);mSpriteVB->Lock(0,0,&pData,0);memcpy(pData,point,sizeof(point));mSpriteVB->Unlock();if (FAILED(D3DXCreateTextureFromFile (mDevice,"sprite.png",&mSpriteTex)))return;-- Render CodemDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);mDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_ONE);mDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ONE);mDevice->SetTexture(0,mSpriteTex);mDevice->SetStreamSource(0,mSpriteVB,0,sizeof(D3DVERTEX));D3DXMatrixTranslation(&matTranslation,50.0f,260.0f,-30.0f);mDevice->SetTransform(D3DTS_WORLD,&(matTranslation * mMatrix));mDevice->DrawPrimitive(D3DPT_POINTLIST,0,1);   
  It seems that the problem was coaysed because the D3DRS_LIGHTING render state was set to TRUE, when I turned it to FALSE the sprite was rendered correctly while moving the camera.   