# A* Pathfinding Gridless With Circles [closed]

I found that A* is an algorithm for grid (or tiled) maps. I want to use it or some alternative of it to my game. The problem is that I have no grid. I have canvas and GameObjects could be at position { x: 23.91324512, y: 131.12334253461 }. How would you do this?

And another question, I have element with stepSize (concretely called movementSpeed), and getPosition().getX(), getPosition().getY() AND getRadius() which returns the radius of a circle.

How would you do A* algorithm with radius?

Btw I am implementing it in Java, so maybe some Java snippet would be helpful.

EDIT

As you may suggest me to create a virtual grid, how do I check if I can move to the next node when I have my getRadius() and all the obstacles getRadiuses

## closed as unclear what you're asking by BlueRaja - Danny Pflughoeft, Engineer, Gnemlock, Alexandre Vaillancourt♦, Tyyppi_77Aug 4 '17 at 12:56

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• I suggest you be a lot clearer about what you are asking, or this question is going to be closed shortly. Supply a picture if necessary to explain what you want. – Engineer Aug 1 '17 at 21:33
• "A* is an algorithm for grid/tiled maps" is a common misconception. A* works for any planning problem that you can describe as a series of discrete options & state transitions. Those transitions do not need to form a regular grid. It's very common to implement A* and similar pathfinding algorithms over continuous space by first discretizing that space into a navigation mesh ("navmesh"), and treating the movement from (anywhere within) one convex polygon to (anywhere within) a neighbouring convex polygon as such a discrete transition. – DMGregory Aug 1 '17 at 22:17
• This appears to be the XY problem. Please describe the issue you're trying to solve first, then your attempted solution. – Alexandre Vaillancourt Aug 2 '17 at 10:01