Guys, any advice on pressure sensitive drums would be helpful

wroachbarrette

ive posted this topic so many times and ive never been able to get any response which means that a no one knows how to do it, or those that do dont feel like explaining, but i could REALLY use your guyses help, i need to figure out how to have volume controlled by how hard you tap on a drum, if you have any thoughts on this PLEASE post them, thanks

LumpApps

There is no pressure sensor on iphone as you probably know so this can't be done. I have a tambourine app out that uses multitouch to generate different sounds. That can be an option for your goal. Pm me if you'd like a promocode to check it out.

wroachbarrette

well, if you check out the garage band application, they use the gyroscope and the accelerometer to detect changed and from that determine how loudly or how the softly the sound should be played, i just need an equation to do that

LumpApps

Ah, I didnt think that would be posibble. I haven't tried GarageBand yet.
In that case I would try a free app that gives you read out from the accelerometer.
Hit the screen the way you think is right and read out the numbers. Then translate it into some equation.

I know I am not giving solutions but just hints. Perhaps you thought of this before.
In that case my appologies.

wroachbarrette

Well, i know how i could do it, i do just need the read outs then an equation that would translate those into different levels, say if it was hit this hard it would be 25 precent, then this hard 50 and so on and so fourth, but id just need help with that

mynameisace

Just make a project with the display text of all the accelerometer readings, note how it changes when you hit it, write down the numbers, on your actors, just do when touch is pressed and accelerometer > whatever number, play however loud.

Ace

wroachbarrette

well, that would work, but what i think the best course of action, would be to create an attribute that every say five seconds or so, changes itself to the say x axis of the gyroscope, then if there is a change that is however below that, then it relates it to a temporary increase in volume

old_kipper

Given that the sound of a drum changes dependant on how hard it is hit, you might want to use 2 or 3 samples to get this effect for each drum and cross mix them based on the velocity of the hit

The first sound could just play anyway as a soft hit on touch

the second sound triggered by a reading of accelerometer Z dropping below whatever you you test and would work,

and the third bringing in a last more percussive sound.

Each of these could be tailored by enveloping each sound based on the length of the time that the accelerometer sat over a specific reading or fixed to an envelope that varied with the output of the accelerometer. It will take some setting up and experimenting with but I think something would be possible. To start with I would try to capture accelerometer readings of hits to see what you are working with and look at the variations so you can build rules based on them. For this I would build a rule that captures the movement by changing an attribute if the input is larger than the current value, and then display that value in a display text in an actor. I would also ad a reset button so you could keep experimenting with it without having to restart the app. A timer would also be useful to work out how long movement continued for, done in a similar way.

I don't have time to build a demo at the moment but I've been very happily surprised what you can do with GS and sound.

I hope that helps

kipper

Metronome49

@Old_Kipper

Double-Plus good.

My thoughts exactly.

GarageBand doesn't just change the volume, it uses different but related samples to really have a sound that suggests more force was used.

old_kipper

Most samplers that emulate real instruments tend to work with multiple samples. The real trick is the matching and overlay of them and working them together. Much of that is down to the recording in the first place but for drums it might not be so crucial (to get at least some quite reasonable 'feel'). And it might be worth putting them in different sound tracks in Audacity in sync, to see if they work together and get an idea of how they should be manipulated once the control side is sorted in GS and you need to know what parameters to vary.

scitunes

I posted this in the other thread but just to be sure:

http://itunes.apple.com/us/app/idevices/id343351276?mt=8

it's a free app someone from this forum made a long time ago that gives you accell data and touch for that matter.

Rob2

@Sci was just about to do the same:) Vmlweb's app has always been a useful starting place when doing clever things with the accelerometer.

wroachbarrette

so your first you would come up with say four different values, one for a light tap one for medium, one for a normal, and one for a loud, then just assign either increases in volume, or a different sound to represent different hits?

scitunes

Yeah if accelerometer is < ???
play sound (in the volume of the sound use the above accelerometer value in an equation of some sort)
Otherwise
if accelerometer is < ???
play sound
Other wise...

something like that i guess. Here's the trouble you may have. If you are holding the ipad up in the air and tap it it will react much differently than if you have it on a table top. Both because of the different orientation and also because the table top will not allow the iPad to move very much.

To solve the first issue you will need to have calibration system in place. I believe Jon Mulcahy has a free template from his z is for zombies game that you can find in the start screen of GScreator.

No idea how to account for the surface that the ipad will be on during the drumming session. You may have to recommend that the user hold the ipad in the air or on their lap (though some people's laps are squishier than others!)

best of luck - I can't wait to see what you come up with as I think you will have to really think outside the box on this one.

wroachbarrette

well guys, im trying this, I made an actor to mediate over the scene, "allot less coding compared to going into all the apps and working from there, so this actors job is to detect changes in the zaxis ofd the accelerometer, and from there depending on what value is given, change the level of the sound, i am about to test this but i worry it will require to much processing power to work efficiently

This would work but i just got the last thing typed in and when i tried loading it onto the ipad the thing froze and now i CANT OPEN IT BACK UP it just spins and spins and spins, this isnt good