Please help!

[vide0n]

First off a bit of background.

I'm a newbie to working with lasers and control - I've only started looking into it about a week ago. I'm trying to do something a little bit different than I expect most would want to achieve with laser projects, and I'm not quite sure about the best way to go about it. The way I understand the process so far is that you sketch your patterns frame by frame in some software commercial or open source, save/output as one of multiple formats and push this out to a laser through a DAC of which many are available, the first stuff I came across was Pangolin equipment.

In terms of patterns for projection I'm not trying to do anything fancy, I'm just interested in projecting a single line, and I'd like to change it's length over time. This is likely to be implemented in a straightforward way with a periodic looping animation that has the line growing and shrinking.

What I would like to achieve is to acquire the ability to speed up/slow down the framerate of this animation in real time with commands - I'd like to be able to write some code that talks to a device over TCP/IP so I don't need to be at a terminal. I'm currently in the process of finding software that can help me achieve this. I find it can be a little tricky investigating software with little documentation.

From what I can gather any of these DACs should suit me but those with software may have measures to prevent me from using another suite? I suppose I'm particularly concerned about this with the Pangolin DAC. This isn't necessarily to say I'm doing it on the cheap, I just want to avoid waste.

Ether Dream
Moncha
Easylase
QM2000.NET
RIYA
Lumax (LaserWorld)
EzAudDac (Sound cards)
Medialas Mamba
Netlase
OLSC
Showtacle Fiesta

As for creation of the animation so far I've identified Laserboy as being potentially useful to me but the process seems to be create -> compile -> run. So I'm not sure if I can play around with the framerate at all really. I'm in the process of setting up a virtual machine with Linux Mint to try and play around with OpenLase. If I had a spare $1000 I'd try LD2000 SDK too, as so far that looks to be my best bet. But then I think I might have to buy the QM2000 as well.

I realise this is a very specific application and quite a long winded post but if anyone can point me in the right direction software/hardware wise or even things that I should avoid doing that'd be a great help. I've spent many hours looking in what information is already out there but I understand that what I'm trying to do isn't really what most people would use this sort of stuff for.

Cheers to anyone who can lend a hand.

[Grix]

I can't imagine you have to spend hundreds of dollars just to do that.

You can use a program like ildaGen, LaserBoy, monkey tools etc to create the animation, and then use f.ex. LaserBoy to convert it to wave format. Then if you get a sound card DAC you can probably use a standard media player that allows you to adjust the playback speed on the go, and use that to play the animation onto the DAC directly. Would only cost like $50-100 for everything (except the projector or course). I don't actually know if it would work but I can't see why not.

[james]

Making a simple line animation that changes in length over time in LaserBoy is very easy.

Being able to change the play rate in real time is not so simple.

If you could change the sample rate of the wave player, that would work to a point.

But if you go to slow you'll see flicker and if you go to fast you'll overdrive your scanners.

However, a single line is a very small amount of information for a frame so you would have quite a range of speed adjustment before you see any issues.

LaserBoy can be compiled for Mac OSX and Linux. So you could use a Raspberry Pi to play the waves and issue the control commands over TCP/IP through a secure shell.

But you don't need LaserBoy to play a wave. It just makes them.

LB is already compiled for Windows. The exe comes in the zip, with the source code and Makefiles for Windows, Mac and Linux.

On the other hand.... If all you want to do is project a line and be able to vary the length of it in real time, then maybe you don't need scanners at all. Maybe you could use a diffraction grating to turn a laser spot into a line and some sort of moving mask in front of the line to block it off from one end or the other.

James.

[mixedgas]

"Write out" or "pencil" is a standard effect on most show software. That draws the 1st point, then 1st and 2nd then 1st, 2nd, 3rd etc in sequence.


Changing scan rate in real time is only a function in a few programs. So you want to start with a dot tracing the path and then move to a increasingly solid image once the Eye's flicker fusion rate is reached, yes?


You could do this In say LSX or Beyond, but NOT in most software.

If this is all you wish to do, your project screams for images on a SD card with a Etherdream....

Can you be specific as to the number of animations you wish to do this with?

Steve

[colouredmirrorball]

Etherdream has OSC support for SD card playback. Could that work?

[vide0n]

Making a simple line animation that changes in length over time in LaserBoy is very easy.

Being able to change the play rate in real time is not so simple. If you could change the sample rate of the wave player, that would work to a point.

But if you go to slow you'll see flicker and if you go to fast you'll overdrive your scanners.

However, a single line is a very small amount of information for a frame so you would have quite a range of speed adjustment before you see any issues.

LaserBoy can be compiled for Mac OSX and Linux. So you could use a Raspberry Pi to play the waves and issue the control commands over TCP/IP through a secure shell.

But you don't need LaserBoy to play a wave. It just makes them.

LB is already compiled for Windows. The exe comes in the zip, with the source code and Makefiles for Windows, Mac and Linux.

On the other hand.... If all you want to do is project a line and be able to vary the length of it in real time, then maybe you don't need scanners at all. Maybe you could use a diffraction grating to turn a laser spot into a line and some sort of moving mask in front of the line to block it off from one end or the other.

James.

"Write out" or "pencil" is a standard effect on most show software. That draws the 1st point, then 1st and 2nd then 1st, 2nd, 3rd etc in sequence.

Changing scan rate in real time is only a function in a few programs. So you want to start with a dot tracing the path and then move to a increasingly solid image once the Eye's flicker fusion rate is reached, yes?

You could do this In say LSX or Beyond, but NOT in most software.

If this is all you wish to do, your project screams for images on a SD card with a Etherdream....

Can you be specific as to the number of animations you wish to do this with?
Steve

The bolded is interesting, will definitely have to consider that James.

I'm not really a programmer, I'm an engineer. What I'm looking to do is project an animation in an indoor space, the changing line animation is in place so that the length of the pattern matches up with physical features in the indoor space. I'm just going for this one particular animation (it's not really your traditional laser show ), but I'm not sure how many frames it will end up having at this stage but I am after a 'smooth' look. My line at a given point in time needs to span the distance between two physical features which varies slightly around the room - which is why I need to be able to change the framerate on demand so that it looks right in real life. I intend to rotate this scanner so that it is capable of covering the indoor space. I'm trying to avoid panning/tilting/translating the projector in an effort to approximate the visual effect, so that's why I am trying to go with an animation. An SD card with etherdream may work and may be what I go with if I'm out of other options, it's just that the scanner is going to be in an interesting spot and I won't be able to get to the SD card easily - this isn't a problem if I can write to it through the network, but I honestly have no idea as to whether that's an option - gut says probably not.

I was hoping to go wireless between the DAC and workstation, is this ill-advised? Does anyone have any advice on what I might use for playback? In the threads on forums I've seen most of you talk about it as a trivial pursuit but I've yet to find out how to actually do it

Thanks for taking the time to respond.

Etherdream has OSC support for SD card playback. Could that work?

It might, I'd just have to look into what OSC really is! Thank you for the suggestion

[james]

Another way to make a line that can be adjusted for length in real time is to just make a wave of a fixed line at full scanner swing and put what amounts to a volume pot before the input to the scanner. Then you can adjust the amplitude of the signal going into the scanner amp, thus varying the length of the line.

You can also add a linear pot with +5V on one side and -5V on the other side and add the wiper to the scanner input to pan the image left to right or up and down.

That's about as real time as you can get!

Scanner signals are analog. They are similar to audio, which is why it is possible to use a sound card for a DAC. The only difference is that audio is almost always DC decoupled with a capacitor, resulting in a signal that is change in voltage over time. Laser DACs need to be DC coupled giving absolute voltage at all times.

Using LaserBoy, you can make this line wave for a few seconds and use Spider Player or similar to loop it. LaserBoy will make a line scan wave that wags back and forth across the line so the laser is never off.

Interesting fact: A horizontal or vertical line only uses one scanner.

James.

[White-Light]

A way of adjusting length so far overlooked is viewable point control.

If you have software that allows you to adjust the number of viewable points drawn in real time, then you can adjust the length of the line that way. You can do that in QS but as QS doesn't include scripting it could have to be hands on. Beyond may allow for it as scripting is possible However, as I'm not familiar with the limits of the scripting, you need to consult someone else on that. Alternatively you could contact Pangolin as it's possible they may add a command if one doesn't exist for what you want to do. I'd imagine you want some kind of random time script with max and min parameters settable, where an event is triggered after a certain amount of random time has elapsed.

Obviously the line has to have plenty of points to do it this way. Drawing a 2 point line won't work.

[james]

You could also use a signal function generator outputting a triangle or sine wave into one scanner.

James.

[vide0n]

Thanks for the advice everyone, the potentiometer solution before the scanner input in particular sounds relatively simple but I continue to search for a soft approach, less hardware, less to go wrong right? In my travels I saw this thread: http://www.photonlexicon.com/forums/...-Skewed-output and wondered if there's a simpler way of distorting the scanner output through the software so I could just use a single frame - I can't imagine a media player having this functionality. In the thread I've linked it was a hardware issue - so not sure if there's any software approach to this. If I can stretch, rotate, otherwise transform at will I wouldn't need an animation - but I expect this may end in disappointment for me.