View Full Version : How would you surface... L.E.D. video wall with "fat" pixels

10-21-2013, 04:58 PM
Normally I just fake this sort of thing, but there must be a better way. I need to render a video wall, not really a typical wall but close enough for argument's sake.

The trick is that that the pixel elements are unusually large, so if I just map an image onto them you'll see multiple colors in some pixel elements. Example attached.

I'm looking for a way to get each pixel poly to be just one color as they would be in reality. I've never found a way to do this with layered surfaces, and I'm still not too savvy with the nodal system. I've poked around in the native nodes and the DP Kit nodes for something that would average the color of each polygon, or better still - sample just the right pixel from the image map and apply that color to just the right polygon.

The L.E.D. polys are all in one object layer. Since there are some 25,000 of them, I'm trying to keep it simple. I'm hoping there's some clever node that offers an elegant solution.

I've scoured through the forums but haven't found anything quite right.

Any ideas out there?

10-21-2013, 05:03 PM
This thread would be a good starting point.... http://forums.newtek.com/showthread.php?79930-Bathroom-tile-surface-with-node-editor

Find the parrot scene. Amazing!

10-21-2013, 05:07 PM

To save having to find the post... I love the node editor!

10-21-2013, 05:17 PM
Ah, quantize.....
I'll have a close look at this.

10-21-2013, 06:03 PM
This might help although it's with instances.


The key is the Replace Spot node which is part of the DP_Filter set of nodes. (plugin)

I'm actually working on a full commercial tutorial covering this type of usage, but I have a few more chapters to add.

I did get it working on just polys with Bryphi's help (and then Denis made a change to DP Kit to make it more straightforward), but I don't remember the set up off hand and that hard drive isn't attached to this computer atm.

Other options:
1) make your image map the same size as the number of LEDs (i.e. 25 leds across = 25 pixels) and use that image making sure to turn off pixel blending and mipmapping so the image doesn't blur

2) make a version of your object with your LEDs scaled down so all the points of each LED is in the same spot. Then use a morph to scale them up to the correct size in Layout. That way when the surface texture is applied the LED will be a solid color

3) same as 2 except make a UV map when the LEDs are in their singularity state and then apply the full-size morph in modeler and then you don't have to do that in Layout

10-21-2013, 06:41 PM
Also, when you figure this out, please post your solution.

Dana, did you mean the morph to occupy, in extent, each pixel array geometry to cover one image pixel, and then be morphed up to full size including border???

10-21-2013, 07:10 PM
I think the solution was in this thread:
http://forums.newtek.com/showthread.php?137507-Part-Info-for-surfacing-question-Colors-per-poly-instead-of-per-part&highlight=dwburman in Post #5. Brian was one step ahead of what I was asking for, but I caught up to it later. If you keep reading, another solution may be revealed. If I remember correctly, Denis added a new output to the Part Info or Part Move node that made the additional connections unnecessary.

It's been a while since I worked on that part of my tutorial, but I intend to get back to it soonish. :)

Jeric: Yes. It doesn't have to relate 1 to 1 to the number of pixels in the image, the LED polygons just have to be covered by the same pixel in the image.

All of the geometry that makes up the LED bulb or "pixel" should be condensed into the same space so that when you apply the image map all of the entire LED is within one pixel in the image map.

10-21-2013, 07:29 PM
Any ideas out there?

Set up weights different for columns, and different for rows.
Like in this video

Then row's weight plug to Image node V input.
and columns's weight plug to Image U.

10-21-2013, 08:41 PM
Wow. Quite a few avenues to investigate. I'll have a go when my head stops spinning ^_^