Author Topic: Gray background instead of black background  (Read 483 times)

Offline masonspappy

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Gray background instead of black background
« on: February 11, 2017, 04:37:23 AM »
I'm trying to render an object  in Terragen (see image) and can get a black background by using Ambient occlusion instead of Global Illumination. But I really need a solid  gray background and can't figure out how to get that. Been playing with it all evening and no further along than I was this afternoon. If anyone could point me in the right direction I would really appreciate it.
Thanks!

Offline Dune

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Re: Gray background instead of black background
« Reply #1 on: February 11, 2017, 04:52:44 AM »
What if you float the object in the air, no planet, and just add a large plane far behind it, self-illuminated in the grey you need.
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Offline masonspappy

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Re: Gray background instead of black background
« Reply #2 on: February 11, 2017, 05:36:13 AM »
Thanks Dune, that worked after a bit of tweaking. The object is supposed to be rendered against a specific gray background (R:247 G:247 B:247).  Even though the plane was set to those numbers, when it finished rendering and got loaded into PSP, the background had changed to (R:250 G:250 B:250). Don't know how that could have happened but there it was.  Had to tweak it a couple of times to get it right, but seems to be acceptable now.
Thanks!!! :)

Online cyphyr

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Re: Gray background instead of black background
« Reply #3 on: February 11, 2017, 08:44:13 AM »
What if you float the object in the air, no planet, and just add a large plane far behind it, self-illuminated in the grey you need.
Or you could not use a plane (who's colour/tone will be affected by it's angle relative to the sun) and change the colour of the background node instead.
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Offline René

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Re: Gray background instead of black background
« Reply #4 on: February 11, 2017, 12:02:51 PM »
Apply the color you want to the background object and make sure all the lights are white. Disable surfaces and atmo visible in the renderer.

Offline Oshyan

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Re: Gray background instead of black background
« Reply #5 on: February 12, 2017, 02:13:28 AM »
The rendering process is inherently going to change the illumination of most any surface color you choose. That's part of what "shading" is. Otherwise it would just show the exact color you chose, and that's not really "rendering". ;) If you literally just want the background to be a specific color, but to maintain all other *realistic* aspects of the render of the foreground object, just float the object, disable rendering of the planet and everything else, and then render out with an alpha and use that to put whatever you want behind the object. Using the alpha is almost certainly the most accurate and least fiddly way.

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Offline masonspappy

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Re: Gray background instead of black background
« Reply #6 on: February 12, 2017, 06:09:52 PM »
thanks guys. really appreciate the help.  :)

If you literally just want the background to be a specific color, but to maintain all other *realistic* aspects of the render of the foreground object, just float the object, disable rendering of the planet and everything else, and then render out with an alpha and use that to put whatever you want behind the object...
- Oshyan
Thanks Oshyan. That was dead-on

Offline masonspappy

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Alpha no longer produced after reboot for windows updates
« Reply #7 on: February 16, 2017, 02:51:15 AM »
So,  was rendering images and including an alpha (tgalpha), and had sucessfully done this literally several dozen times.
Then got notification that maintenance had been applied to my PC and I would need to reboot. So I did, but prior to doing this I deleted all the regular images plus the companion TGalpha images from their default folders.  Also saved the testing environement as a TGD,  and assumed I would simply reboot computer, start Terragen and load the testing environment.
But after rebooting and restarting Terragen, I'm no longer to get alpha images  (meaning no alpha images appear in the TGalpha folder.)
Been trying to fix this for a few hours but getting no where.
If anyone has any ideas about what's wrong here I would love to hear them!!
Thanks!


Offline masonspappy

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Re: Gray background instead of black background
« Reply #8 on: February 16, 2017, 04:15:10 AM »
Never mind, finally figured out the problem.  :)

Offline Dune

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Re: Gray background instead of black background
« Reply #9 on: February 16, 2017, 07:22:15 AM »
What was it?
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Offline masonspappy

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Re: Gray background instead of black background
« Reply #10 on: February 16, 2017, 11:54:16 AM »
I was still rendering image sequences to the default output folder: C:\Users\CLH\Documents\temp.%04d.tif and C:\Users\CLH\Documents\temp.IMAGETYPE.%04d.tif.
Once I created new output directories and pointed 'Output Image File' and 'Extra Output Images' to them, the setup worked.
........................except.......................................
 Got this strange thing going now where the output image is created just fine but the lower half of the alpha image is missing (see attached images below). This cut-off was consistent across all animation images I've created. 


Oh, wait.  I might know the answer.   I was originally using a plane object as a backdrop. It can't be seen in the render but  I'm guessing the camera was still picking it up and processing it and that's what's showing up in the alpha images.  When the latest test sequence finishes I'll duplicate the original setup and see if that's the problem
« Last Edit: February 16, 2017, 01:08:08 PM by masonspappy »