# How to calculate final force vector for the SKSpriteNode

I am creating space game which has an effect similar to black hole's gravitational effect. Wherever the spaceship is going, the black hole will attract it, summing up all the vectors together.

I know SKFieldNode has a method customFieldWithEvaluationBlock: that allows to calculate everything myself, but might it be another way to do that?

I have tried almost every type in SKFieldNode, but nothing helped.

1. There are some side effects that don't suit me (i.e. If I use an electric or magnetic field, the object repels from the black hole)
2. Moreover, moving with SKAction (i.e. for the spaceship) doesn't allow me to sum all movement vectors together (I cant do - (void)moveTo:duration: actions simultaneously, even with grouping the actions)

What can you advice me? !

• Beraliv, I deleted greetings part because they are frowned upon by the community members. If you take a look at the other questions, you see what I an saying, please don't take it personally. Did you test vortexField? – Iman Sep 10 '15 at 17:53
• @lman thanks, I understood. Yeah, I tested it, need to adjust the parameters to check if it suits. – Beraliv Sep 10 '15 at 17:56
• did you succeed to use vortedField for your blackhole? please share your experiance. – Iman Sep 16 '15 at 21:28