While I am very new to Unreal 4 I have been trying to achieve this for hooours now with no luck. I would ideally like the explosion to be very fast but then rapidly slow down just before it reaches its desired size (or time) and then for all the particles to completely stop moving. Okay so basically what I’m trying to achieve is a holographic star map that ‘explodes’ open. In the next section we'll look at some more complex, special-purpose applications of the random motion expression.Hi everyone, first post (of many I’m sure)!
#Freeze particles after effects particle playground code#
For completeness, here's the modified code for Rotation: This is just what's left of the random Position expression with added code to pick up the segment start and stop times from the Point Control, and the code that uses those values as the two seeds for the random number generator. Start = effect("Point Control").param("Point") Įnd = effect("Point Control").param("Point")
Now let's look at how we would modify the random Position expression to make use of this: 75 and 1.0 seconds - so that you can more easily observe the synchronization.) You'll note that all that's in this code is the calculation of the segment start and stop times. Notice that the random Position, Rotation, and Scale changes for each layer are now synchronized (I've made the segments longer in this example - between. Well, it turns out we can use the start and stop times as random seeds and they will work just fine because they are also unique within the segment. The Point Control will calculate the start and stop times, but how do we make sure that the other expressions are able to get the same random property at each frame of the segment? I mean, in the previous self-contained versions, we were using the segment index as the random seed because we knew it would be unique to the segment, but that information is not available (it's hidden inside the Point Control expression). Then we'll modify the other expressions to pick up the timing information from the Point Control. So our basic strategy is to move all the start and stop time calculations to a Point Control expression so that it will accessible to the layer's other expressions.
Why a Point Control? A Point Control is two-dimensional and we need to make the segment start time and end time available to each of the layer's expressions so that they will be in sync. We'll use a Point Control as a read-only global variable. So how do we get all these expressions for all these different properties to have the same random timing? We use an Expression Control (in a way that it probably wasn't intended to be used). All that's visible to other expressions is the final output value. Remember that expressions can't get at variables in other expressions and there are no true global variables. That can be very useful and may be what you want, but it would also be nice to be able to sync all the randomness of a single layer so that each new segment contains a new position move, a new rotation, a new opacity, etc, and that they all ease in and out together. That means, for example, that a new Rotation segment may begin in the middle of a Position move. In the examples where we have multiple properties being randomized, each property expression is operating independently from the others. Again, we only need to make a few minor modifications to get it to work for Rotation. Now let's look at adapting our Position expression to Rotation. Then we use the random x position and the fixed y position to generate the side-to-side random motion. In the next-to-the-last line of code, we set the variable "y" to position. The y coordinate will remain whatever it was before the expression was applied. This is because we're only going to vary the x coordinate. The main difference is that we have changed to a one-dimensional maximum Position. If you compare this expression to the final expression from the previous section you'll see that there are few differences.
Dummy=random() //this is a throw-away valueĮase(time,start,end,)
0 kommentar(er)
