How do I use edge blending with a Matrox TripleHead2Go?

[davey_t]

Hi, 

I'm in tech for a play opening this week and wish to edge blend three projectors. I have the projectors arranged 3 wide with overlap, set up QLab w/Multi-screen Surface, assigned each of the screens, but I still can't seem to get the edge blending to make any change. How do I do this?

I am using a Matrox THTG with three 1024x768 projectors overlapping by what looks like approximately 35%, and wish to blend the edges to smooth out the brightness across the 2 seams of overlap. I expected QLab to automatically do this when I assigned the partial screens. It did not automatically blend anything. Did I miss a key step in the process?

I did the following:

Workspace Settings > Video > Add New Multi-Screen Surface

(Typed in the popup window) Projector Resolution "1024x768" ; Arrangement "3 x 1" ; Overlap "%35"

(In the lefthand toolbar - Assigned each of the 3 Projector) ; Assign Screen > Partial Screen > Display > 3 Wide > Virtual Screen (1024 x 768)

"Edge Blending" Button is toggled on

What am I missing?

Are corner pins used? When I try to click and drag them, my cursor seems locked in place; but when I release the mouse click, the corner pin has jumped to a new position. I also can't click and drag it back to it's original position. Clicking undo doesn't undo the change either. How do I control corner pins better?

Macbook Pro 2010; OSX 10.10.1 ; 2.4 GHz Intel Core i5

NVIDIA GeForce GT 330M 256 MB

Using QLab 3.1.9

Any swift help is much appreciated!

Thanks!

~ Davey

[Chris Ashworth]

Hi David,

A couple of questions:

1) Are you looking for the blending on the projector output, or in the audition window? (It will only appear on the actual projector output.)

2) If you create a fresh workspace and try making a new surface with just, say, 2 outputs that overlap, does it work?  I’m wondering if the workspace got into some state that it is encountering an error, where a separate document might indicate that you are not missing steps and do see edge blending in another case.

Best,

Chris

[micpool]

Your set up looks correct.

I am unclear though what you mean by "it didn't blend anything". Do you mean that the correct images with overlaps are not present on each projector, or that they are ,but the blended areas are either too dark or too light.

With regard to fine control of corner pins; If you select a corner pin so it goes solid, you can then adjust that pin using the arrow keys, in 1 pixel increments, or 10 pixel increments using the shift key as well. When you click an are of the screen which is not a pin then the pin should stay where it is.