Introduction

As some may be aware of, the latest beta introduced the first pieces of Construct's own implementation of a scene graph.

Some people are excited, for good reasons. But I read from quite a few that have no idea what the fuss is all about. Allow me to explain...

First, what is a scene graph?

Scene graph is a fancy name for a tree structure, in which a root parent object can have children and then those, children of their own. A quick search in Google let's me find an image to convey this, here it is.

In the context of Construct, this new feature allows you to establish that kind of relationship between plugin instances (at the moment only Sprite instances).

With that hierarchy created, it is possible for the runtime to calculate translations, rotations and scaling of a child based on that of it's parent.

• Example 1: a parent is translated in X for 100 pixel, all it's children will follow to ensure they maintain their relative position to the parent.
• Example 2: a parent rotates then all children will adjust their positions to rotate around the parent's origin as well as adjust their own rotation.
• Example 3: a parent changes it's scale, all children will adjust their positions as well as scale in response to the parent's changes.

The most common case would we for any of this things to happen at any given point and Construct will calculate the correct position, rotation and scale for all the instances involved.

Keep in mind that all child transformations occur around the parent's origin. I think this is better demonstrated by this small example project.

https://www.dropbox.com/s/etwun316sox4lne/SceneGraphExample.zip?dl=0

New runtime actions

The latest beta introduced 3 new actions, Add Child, Remove Child and Remove From Parent. To make things easier on ourselves, at the moment these are only supported on the Sprite plugin, as the feature matures and we iron out bugs and implement user feedback more plugins will be supported.

• Add Child: This one is used to add a child to another instance. It's pretty straight forward. When an instance is added as a child of another one there is no immediate change, it is only when the parent is modified that the child will respond accordingly.
• Remove Child: This is pretty straight forward as well, remove the specified child from the picked parent.
• Remove From Parent: This is similar to Remove Child, but allows you to remove the picked instance from it's parent, without knowing to which instance it belongs.

I think this is it for now, I will update this thread as more features are added. If you have any questions I'll try to answer them here.

This is a difficult problem.

The gist of it is that the client should never be trusted, the server is the only source of authority. As such the server should always perform validations on a score before it deems it valid.

That is the difficult bit, what is a valid score? That is completely tied to each game and depending on it's logic it might be impossible to determine if a score is fake or not. Even if you can determine if a score is fake, how can you handle a client sending the maximum valid score every time?

Short story, validating a single value sent over a single request is difficult if not impossible.

Possible solution:

I guess you could try using web sockets so the client communicates constantly with the server about what it is doing, sending messages each time the score increases. When the game ends the client could send a message saying the game ended and the server can tally the final score.

If a client get's funky and starts sending too many messages to increase it's score, you can determine it is trying to cheat. Sending messages with score amounts you know can not happen in the game? Cheater. Like that there are many things the server could do to spot unusual behavior on a client.

The problem with that approach is that to send a valid highscore you need a stable internet connection, if you don't the server can't make real time validations, so it won't accept any scores. This might be a compromise you are willing to make, you could have two modes, "For fun" which does not perform real time validations and can not save highscores, and "For score", which does all the validations but needs the stable connection.

Maybe there are easier solutions, but can't think of them right now. Good luck!

Coincidentally this feature has been added to Timelines, and will be landing at the start of the next beta cycle.

It was implemented by means of the "initial frame" property of the Sprite plugin. This means a timeline will interpolate the value of that property and assign a new frame as the timeline progresses. There will be a few things to look at for when using it.

Because the timeline will be changing the frame of the animation, the plugin itself will not be playing the animation, so all triggers and conditions that the plugin would normally execute, will not happen. Instead you will need to rely on similar triggers and conditions on the timeline itself.

The only exception to this, is the On frame changed trigger that the sprite plugin will execute while being animated by a timeline.

Furthermore, attempting to play a Sprite animation normally while it's current frame is modified by a timeline will result in strange behaviour. So it will be a case of picking one or the other, but not both.

I doubt this will be added to Tweens, it is a rather specific behaviour and while it is possible to implement it, it would be a pretty ugly monkey patch.