The lerp expression take the input range made by the two first values and consider it as equivalent to 1, then returns the value that corresponds to the x ratio. In other words, it takes the difference between the first two values, multiply it by the interpolation ratio and adds the result to the first value.

This is what happens when you set a variable to lerp(variable,600,0.5) every tick, considering that the variable initial value is zero:

<img src="http://dl.dropbox.com/u/7871870/construct/lerp-01.jpg" border="0" />

In the first tick the variable will be set to the middle point between the range 0-600, which is 300. In the next tick the lerp will take the current variable value that is 300, and return the middle point of the range 300-600, which is 450. In the third tick the range will be 450-600 and lerp will return the middle point 525, and so on for the other ticks until it reaches 600.

The rate at which the variable changes is a curve and not a straight line, so you get a deceleration as the variable approaches the destination value.

If you want a constant rate you need to set constant values to the range and increment the ratio every tick. So you need to do something like:

+Every Tick

set width to lerp(0,600,variable)

set variable to clamp( variable + dt / duration ,0,1)

Being 'duration' the desired time in seconds to go from 0 to 600. Which means that if duration=2 the width of the object will go from 0 to 600 in 2 seconds.

The clamp expression is used to ensure that the variable value will always stay between 0 and 1, otherwise the width of the object would increase forever.

Our entry.

Made by a team of 2 people: me and my girlfriend.

*Controls:

mouse - aim

left click - launch

R - reset level

Esc - menu

It's unfinished, still missing an end with a score screen, improvised menus, some bugs, no sound, but you can get the feeling of the mechanics and visuals.

Besides everything we are happy with the results, and enjoyed this year edition. :)

I guess that if it's static you are probably planning to use it as ground/walls, so in this case I think it would be better to use invisible tilled-backgrounds as collision. Lots of objects with bounding-box collision are probably faster than one giant collision polygon.

I was thinking, the confusion is made because there's no clear feedback of what is being undone. It would be clearer if the interface displayed the context of the undone event.

For example, if you are in the event-editor and undo something from the layout-editor it should automatically change the view to the layout-editor so you can see what is being changed. In the same way when you undo an event it should select the undone event so the user can be aware of what is being changed.

I think the problems could be minimized this way.

Remove the platform behavior, it doesn't work well with physics.

Move the vehicle through forces instead.

Apply Gravity_Force*Object_Mass instead of just the Force and you will have proper gravity.

I made an example here:

http://dl.dropbox.com/u/7871870/construct/prr-layer-rotation-positioning-01.capx

Some friends of mine started using dropbox for a project they are making in Unity and they regret deeply. They said that every once in a while dropbox loses track of some versions and everything gets messed up. So if you want to avoid headache use a proper version control software like Tortoise.

I'll be participating at PUCPR here in Curitiba. As of now it seems to be the world's largest jam site with 196 jammers.

Construct is the ideal software to use in jams since it doesn't waste the majority of your time with coding.

The last two editions we used CC for our entries, but this year I'm considering using C2. Let's see, depending on the game idea I'll choose the more appropriate one.

Add this action to handle variables:

"Increase/Decrease if lower/higher"

7Soul: you can achieve this with conditional expressions (more info here).

capx example

Hey Ashley, would be possible to add a Mass parameter to the physics that overrides the mass of an object? Or that sets the density to match a specific mass?

I recognize that the mass based on the density x area have the benefit of adding realism to the simulation, but it also takes away control. It's very hard to design a game based on weight ratios among objects, because it's impossible to calculate the mass since we don't know the area value. If it's based on specific weights then it's just not possible to implement it right now.

Just confirming that I get this error too, and right after C2 crash.