Present a modal view controller with size<screen size

gistfile1.m

//Assuming the view controller's size is WIDTHxHEIGHT

//Calling the view Controller:
    CustomViewController *vc = [[CustomViewController alloc] init];
    vc.modalPresentationStyle = UIModalPresentationFormSheet;
    [self presentModalViewController:vc animated:YES];

//In the view controller:
-(void)viewWillAppear:(BOOL)animated
{
    [[self.view superview] setAlpha:0.0f];
}


-(void)viewDidAppear:(BOOL)animated
{
    CGRect f= [UIScreen mainScreen].bounds;
    CGPoint p = CGPointMake(round(f.size.width/2.0f), round(f.size.height/2.0f));

   
    [self.view superview].bounds = CGRectMake(0.0f, 0.0f, WIDTH, HEIGHT);
    [[self.view superview] setCenter:p];

    
    [UIView animateWithDuration:0.1
                          delay:0.0
                        options: UIViewAnimationCurveEaseOut
                     animations:^{
                         
                         [[self.view superview] setAlpha:1.0f];
                     }
                     completion:^(BOOL finished){
                         
                     }];
}