Non-Rectangular Video Surface Mapping Help - Masks and Feathering?

[musicaljinn]

Hi all,

I'm looking to do some projection mapping using Qlab 3.1 - I know how to create a surface and work with control points, but I have to say that the interface for working with non-rectangular shapes is very difficult.  What I would like to do is to project an image to an oddly shaped surface (with multiple angles, cuts and holes (but otherwise flat), not have the perspective change, but be able to set control points so that the video won't warp or sneak onto the set behind the surface.

Basically, when I was working with Qlab, I was creating splits in order to map out a very intricate shape, but with those splits came a ton of headaches as the image itself got warped and distorted (as you can't use bezier lines without doing so?).  What I really want to do is to add control points and reshape the projected map to my liking, being able to have bezier control without having to deal with perspective issues -- I just want a flat image, cut out and on a surface.  But it seems like I cannot do this easily.

So I looked around and tried the mask option.  I created a mask in Photoshop for the image using the set renderings, but you all know that the renderings never match the actual product. So I ran into troubles with that as well considering with the masks doing what I needed, I could only use the Linear setting, and thus couldn't make fine tuned control points.

So I continue to groan and have headaches because I can't adjust or add individual control points without using splits?  Or can I and I'm just uninformed?

My second question is that I would like to 'feather' out the edges of the surface, basically not have a hard line for the image (I'm projecting on tattered moving fabric...I hate it).  Is this possible?  Or do I have to do the gradient in a mask on photoshop?  Does Qlab support alpha channels like that for a mask?

Thanks y'all, I just find it so completely frustrating that I can't just add control points that have bezier curves freehand, similar to how Isadora does (but I can't use Izzy because it doesn't have the show control capabilities that I need for this show).

[Andy Dolph]

the way I've done that kind of situation is to create a rectangular surface that includes the whole area I want to project on, and then create a mask in photoshop and apply that mask to the surface.  The easiest way I've found to do that, if I have access to the venue is to do it with the projector connected to the computer, and drag a photoshop document of the correct pixel size onto that monitor, then use the masking tools in photoshop to essentially paint a mask onto the physical environment.  Then output that as an image (the mask goes in the image not the alpha channel)...

--
--
Change your preferences or unsubscribe here:
http://groups.google.com/group/qlab
 
Follow Figure 53 on Twitter: http://twitter.com/Figure53
---
You received this message because you are subscribed to the Google Groups "QLab" group.
To unsubscribe from this group and stop receiving emails from it, send an email to qlab+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/qlab/5219791c-7d0d-4230-8397-f69515f0a16b%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[musicaljinn]

That's brilliant about using photoshop on the actual surface instead of 'guess and check' -- which is actually what Figure 53 offered up (saving the grid image and then using it as a reference while working photoshop), which definitely will work.  But this will Really work.  Thanks for basically changing my workflow = my life.

To unsubscribe from this group and stop receiving emails from it, send an email to qlab+uns...@googlegroups.com.

[Alexander (Mailing List) Taylor]

I know this won't work for 99% of people here (especially because it takes a hack and a discontinued piece of software) but I'll actually fire up Shake (yes, running the latest OS) and set the broadcast monitor to use whatever projector/screen I'm working in.  That way I can change the actual parameters of the mask (or effect, etc) while seeing it on the actual projector.

But, unless you happen to have a license and installer for Shake, and have gotten it to work on recent versions of OS X (sorry, meant to say macOS), this is just an interesting tidbit.

Alexander

To view this discussion on the web visit https://groups.google.com/d/msgid/qlab/043d3254-bf9e-41aa-a675-42395d38f4cf%40googlegroups.com.

For more options, visit https://groups.google.com/d/optout.

The Right-To-Know Law provides that most e-mail communications to or from School District employees regarding the business of the School District are government records available to the public upon request. Therefore, this e-mail communication may be subject to public disclosure.

[Andy Dolph]

glad to help.  It's worked well for me so long as there's enough pixels around the edge of what you are projecting for the photoshop window...

To unsubscribe from this group and stop receiving emails from it, send an email to qlab+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/qlab/043d3254-bf9e-41aa-a675-42395d38f4cf%40googlegroups.com.

[micpool]

If you create a document in Photoshop on your main computer, drag that document tab to your projector screen and then go into full screen mode you will just have the document without any stuff around it on your projector.

Mic

[micpool]

Here is a screenshot showing how you can use Photoshop to draw a mask on a QLab screen that has been warped and keystoned in QLab.

Basically you open your Photoshop window on your main screen. Select the image area as in Camtwist and then use that as a camera input to a cue in QLab that is set full screen on your projector.

Mic

[Andy Dolph]

Another amazing idea from Mic! Never thought of that one...

Sent from my iPhone

--

--
Change your preferences or unsubscribe here:
http://groups.google.com/group/qlab
 
Follow Figure 53 on Twitter: http://twitter.com/Figure53
---
You received this message because you are subscribed to the Google Groups "QLab" group.
To unsubscribe from this group and stop receiving emails from it, send an email to qlab+uns...@googlegroups.com.

To view this discussion on the web visit https://groups.google.com/d/msgid/qlab/778b9548-de8c-4827-9770-f0315397e35c%40googlegroups.com.

[musicaljinn]

Jeez. That's incredible. Do you think it would be at all possible to do a video walk through of that process? Post it to YouTube? I bet there are other designers that would greatly benefit from this sparkling wisdom. I bet Figure 53 would share it.

[micpool]

I'll put it on  www.qlabcookbook.com when I get a chance.

If you haven't found this site before you may find some other stuff that is useful to you.

In the meantime if you get CamTwist, all the setup screens required are visible in the screenshot so if you copy that set up (changing the screen din=mensions and mask document to your projector resolution it should work straight away.

Mic

[musicaljinn]

Wow. Your site is amazing.  Thanks for the link.  Always excited to learn more and do more.

[Jeromy Hopgood]

There's been some good ideas shared already for creating your masks. It always depends on how you're going to be using QLab for the show as to what works best. For simple masking, I will often create the shape I want as a mask through the surface control and take a screen shot of this. Import this into Photoshop at the correct size and then use the mapping as a guide to draw your mask. Of course, this only works well for a surface that hasn't been warped through the surface controls. For warped surfaces, Mic has a great idea there with CamTwist.

Gradients are done easily by changing the opacity of your brush in Photoshop. Masks are done as black and white images where black is completely opaque. If you use a black brush set with a lower opacity, this will transfer inside of QLab. One good way to get the kind of look you're asking for is to use your smudge tool inside of Photoshop to get that wispy look with some level of translucency.