box2d base way to integrate box2d into phaser3.

[j.c]

actually I have done this, but with the unit transformation issue, I need to find a best way to refactor my existing code.

as you know box2d unit is meter, game unit is pixel, so when you create box2d Bodies you need to use a fixed factor you specified for example 100px = 1meter, so they are in the game world is really small for example a basketball is 0.3meter (30cm), the corresponding pixel should be 330px but if you don't scale your game world up it will be displayed as 0.3px , to scale game world bigger is very easy in Phaser3, there are a few ways to do that, like directly set camera.zoom etc.

now another problem comes, I don't need my basketball in the game looks so big, if in pure GL code I can use gluOrtho2D to fix my display proper.

so how can I achieve this in Phaser 3?

 

 

 

 

[j.c]

@rich do you have any suggestions on this? thanks.

[j.c]

refer to post also:  https://stackoverflow.com/questions/28028121/how-many-pixels-is-a-meter-in-box2d

 

[j.c]

my current thought is to write a customized pipeline that handles all things related to coordinate and size scaling, and then finally use camera to zoom in the screen.

don't know if this is a 'good' way? @rich

[1p0]

@j.c a working example, you may find the answer in the factors inside:

http://lo-th.github.io/crossed/phy_b2d.html

click the github fork me on top to see and clone the whole repository. The content of that particular example on pixi box2d is this one:

https://github.com/lo-th/crossed/blob/gh-pages/phy_b2d.html

It's an old version but check the function update() { ... }

 

[j.c]

@1p0thanks man, I finally use PTM to scale & sync position with my sprites in the frame update. so the box2d variables can stay the same always.