Collision Between 3D Objects extension

[github-actions]

Description

This extensions checks for collisions between 3d objects as condition and returns true if they are colliding.

How to use the extension

Check the collision of 3D Objects and returns true if they are colliding so you can act accordingly like separate two objects action etc.

Checklist

• I've followed all of the best practices.
• I confirm that this extension can be integrated to this GitHub repository, distributed and MIT licensed.
• I am aware that the extension may be updated by anyone, and do not need my explicit consent to do so.

What tier of review do you aim for your extension?

Reviewed

Example file

CollisionBetween3DObjectsExample.zip

Extension file

CollisionBetween3DObjects.zip

EDIT: Added more information on description on the usage, limitations and examples of the extension.

[D8H]

Thank you for submitting an extension.

I guess intervals intersection can be checked with a simpler formula like this one: aMin < bMax and aMax > bMin

I have some concerns:

• It won't work for 3D models because of custom origin.
  • but maybe it's fine to only use boxes, I guess it could be seen as the 3D hit-box, maybe some sort of 3D sticker extension would help.
• It won't work for boxes rotated around y or x.
  • it could be ok with a different wording like "Intersect on Z", walls are probably only rotated on Z.
• I don't know how much a collision check is useful without a separate action.
  • If the action doesn't check X and Y, I guess it solve the issue.

Is the use case to check collision with walls on several floors?

[VanCastar]

I have some concerns:

* It won't work for 3D models because of custom origin.

I've added a notification on the description that to have proper 3d Model collision working the origin should be set on bottom middle of the object.

  * but maybe it's fine to only use boxes, I guess it could be seen as the 3D hit-box, maybe some sort of 3D sticker extension would help.

I added also a notification to use hidden 3d boxes as collision boxes as done sometimes with 2d Sprites.

* It won't work for boxes rotated around y or x.
  * it could be ok with a different wording like "Intersect on Z", walls are probably only rotated on Z.

This is true, I added a notification to keep the models upright rotated only on Z-axis and a use case examples.

* I don't know how much a collision check is useful without a separate action.

This is great for checking if the separate action is needed.
Also to identify objects you have bumped into (like to open doors, or move furniture for example).
I also use this to

  * If the action doesn't check X and Y, I guess it solve the issue.

It doesn't check for X/Y inside the extension but the 2d collision and then if the object are colliding on z-axis at any part.

Is the use case to check collision with walls on several floors?
Yes exactly this among others(Floors, walls, pillars, stairs, furniture, obstacles, doors, enemies on multiple floors.)
I added an example explanation to the description for the use case.

[D8H]

• If the action doesn't check X and Y, I guess it solve the issue.

It doesn't check for X/Y inside the extension but the 2d collision and then if the object are colliding on z-axis at any part.

My suggestion was to have a condition "BoxA intersect on Z with BoxB", "BoxA is on the same Z level as BoxB" or another wording to make it clear that it's only a naive checks of on Z positions and not a real collision detection.
People would use it next to the 2D collision condition or the 2D separate action according to what they want to do.

[VanCastar]

This extension is included in the collection of extensions called ToolsFor3D in #1050

[D8H]

I credited you on this extension:

• [Community] 3D jump #1145

If you have time to test it, please tell me if you see improvements that could be made.

[VanCastar]

I credit you on this extension:

* [[Community] 3D jump #1145](https://github.com/GDevelopApp/GDevelop-extensions/pull/1145)

I you have time to test it, please tell me if you see improvements that could be made.

I'll take a look at it later this evening...

[D8H]

I also credited you on this extension:

• [3D collision] Check collision and distance between 3D objects #1156

If you have time to test it, please tell me if you see improvements that could be made.

[D8H]

Since the other extension was merged, I'm closing this PR.
Feel free to open it back if you still want to continue working on this extension.