Check Distance Within Certain Angle

Medo Mex · 2013-06-30T13:59:44

I have a character and want to check if there is a certain model is in front of the character (cone visibility check) I'm not sure how do I get cosMaxAngle, I think it has something to do with field of view, if so how do I get the character field of view? (I have the character transformation matrix) BOOL CheckVisibility() { D3DXVECTOR3 view = target->GetPosition() - character->GetPosition(); float distance = GetDistance(character->Position(), target->Position()); if(distance > 100.0f) return false; //not visible, too far D3DXVec3Normalize(&view, &view); //view = normalize(view); D3DXVECTOR3 enemyLookDir; D3DXMATRIX ZUnitVec; D3DXMATRIX matRot; D3DXMatrixTranslation(&ZUnitVec, 0.0f, 0.0f, 1.0f); // matrix holding position of vector pointing to positive z D3DXMatrixRotationYawPitchRoll(&matRot, D3DXToRadian(character->rotationX), D3DXToRadian(character->rotationY), D3DXToRadian(character->rotationZ)); D3DXMATRIX m = ZUnitVec * matRot; enemyLookDir = D3DXVECTOR3(m._41,m._42,m._43); // Get vector from the matrix D3DXVec3Normalize(&enemyLookDir, &enemyLookDir); // Cosine of the angle between the view vector and the direction the enemy is looking float cosAngle = D3DXVec3Dot(&enemyLookDir, &view); float cosMaxAngle = ??? // I think I should use the field of view here? how? I want the character vision cone to be limited to 90 degrees // Check if player is inside the cone if(cosAngle < cosMaxAngle) return false; // Not visible return true; // Visible }