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rcallicotte
02-17-2015, 03:46 PM
I have searched and seen I need to save the final render from LW as a TGA or PNG-32. However, this doesn't fix my lacking a valued ALPHA. I see an alpha in the TGA, but it's all black. The render is fine. But, maybe because I'm using Image World for lighting? Very confusing. In Modo, the ALPHA is just there; no convolution. Of course, it's my ignorance. So if you have an idea, would you help?

ernpchan
02-17-2015, 04:37 PM
You sure you don't have some geo that's acting as a backdrop?

JoePoe
02-17-2015, 04:53 PM
Alpha is all black.... where??

In LW image viewer?
That would mean NO geometry and I'm guessing your render would then, not be fine :).

So I'm guessing it's all black in Photoshop?
.... which would mean ALL geometry.

So I'm going with Ernest....

....Image mapped to a sphere?

rcallicotte
02-17-2015, 05:04 PM
No geo as a backdrop. The viewer shows the image, once rendered. Just no ALPHA. No image mapped to a sphere. I appreciate you answering. Here's what I have.

An exploded view from Bullet. Rendering just one frame. I am using Image World for lighting as well as a spotlight and two point lights. No background. Actually, I take that back. Just now, I selected Use Background in Compositing.

Results:

TGA - has a black ALPHA
EXRA - has a black ALPHA
PNG32 - completely blank
PNG24 - renders fine, but has no ALPHA (of course)

I was able to do this previously, so I'm sure there's something I'm doing that is a problem. I think I'll turn off Image World to see if that is causing the problem and get back with you all.

jeric_synergy
02-17-2015, 05:07 PM
There's no geometry? Isn't geometry a prerequisite for an alpha?

JoePoe
02-17-2015, 05:15 PM
There's no geometry? Isn't geometry a prerequisite for an alpha?

I think he means no geometry as a backdrop.



Can you post a render so we can see what you're dealing with?

Neither Image world nor using a Backdrop Image/Color should nullify an alpha :stumped:.

rcallicotte
02-17-2015, 05:27 PM
I didn't say no geometry or did I? Anyway, it's a Bullet shatter...so lots of geometry. And it's worked before, so I'm certain something was changed by me. I just dismantled Image World and took away the Use Background in Compositing. But, it wasn't bright enough. Still plan to do this and then get back with you to see why seemingly adding Image World or something else would have affected the ALPHA.


There's no geometry? Isn't geometry a prerequisite for an alpha?

rcallicotte
02-17-2015, 06:02 PM
Here's the LWS, if anyone wants to look at it. I'm not including the Image World image, which is just a simple HDR.

https://www.dropbox.com/s/sgc31ge9r2zakpn/ice_explosion_005.lws?dl=0

JoePoe
02-17-2015, 06:08 PM
No .LWO(s) my friend?

Sensei
02-17-2015, 06:57 PM
Here's the LWS, if anyone wants to look at it. I'm not including the Image World image, which is just a simple HDR.

https://www.dropbox.com/s/sgc31ge9r2zakpn/ice_explosion_005.lws?dl=0

With my objects it renders permanently black..

rcallicotte
02-17-2015, 07:52 PM
Here's the LWO. I render something fine. Just no ALPHA.

https://www.dropbox.com/s/jmhfvusw1i7kj1k/ice_explosion_002.lwo?dl=0

jeric_synergy
02-17-2015, 07:56 PM
I didn't say no geometry or did I?
http://forums.newtek.com/showthread.php?145677-No-ALPHA&p=1421871&viewfull=1#post1421871

rcallicotte
02-17-2015, 08:12 PM
Thanks Jericho. Changed.


http://forums.newtek.com/showthread.php?145677-No-ALPHA&p=1421871&viewfull=1#post1421871

JoePoe
02-17-2015, 08:29 PM
Right. Thanks for the lwo.
Okay, I'm going with the 100% transparency on your surfaces :).
Change that and you'll get an alpha.

If it's glass or ice you're after, I'd use Dielectric node instead.

rcallicotte
02-17-2015, 08:35 PM
I am using the dielectric node and 100% transparency, which makes me wonder what happened when I uploaded the file to you all. Is it just lost without its LWO?


Right. Thanks for the lwo.
Okay, I'm going with the 100% transparency on your surfaces :).
Change that and you'll get an alpha.

If it's glass or ice you're after, I'd use Dielectric node instead.

Sensei
02-17-2015, 08:40 PM
100% transparency = 0% alpha. That's obvious.
With any surface.

rcallicotte
02-17-2015, 08:47 PM
God Sensei. Be a jerk.

Anyway, I haven't found this true in Modo. I get an alpha based on the actual images that render, which is (by the way) not all transparent. There's actually light and stuff in that clear object, bouncing around, etc.

rcallicotte
02-17-2015, 08:49 PM
Image.

https://www.dropbox.com/s/uj1wh85vsdv339t/ice_blocks_001.png?dl=0

Sensei
02-17-2015, 09:00 PM
RGB, black is 100% transparent, 0% refraction
127067

Alpha:
127068

RGB, black is 100% transparent and refraction (RI=1.33)
127069

Alpha:
127070

You can change it by playing with Advanced > Alpha Channel and pick option from drop-down..

rcallicotte
02-17-2015, 09:09 PM
Thank you very much, Sensei. You did not need to do that. I will remember your kindness.

In the meantime, I've got an education coming my way...thanks to you.



RGB, black is 100% transparent, 0% refraction
127067

Alpha:
127068

RGB, black is 100% transparent and refraction (RI=1.33)
127069

Alpha:
127070

You can change it by playing with Advanced > Alpha Channel and pick option from drop-down..

MSherak
02-17-2015, 09:28 PM
I have searched and seen I need to save the final render from LW as a TGA or PNG-32. However, this doesn't fix my lacking a valued ALPHA. I see an alpha in the TGA, but it's all black. The render is fine. But, maybe because I'm using Image World for lighting? Very confusing. In Modo, the ALPHA is just there; no convolution. Of course, it's my ignorance. So if you have an idea, would you help?

First set your CS (ColorSpace) to sRGB to insure the correct colors from your textures. This will also fix your alpha output to linear instead of sRGB. Also your surface is 100% in the transparency and since your alpha for the surface is set to surface opacity it sees nothing for the alpha. The Alpha Value will show you how much the object is affecting the alpha and in this case it is 0. So if you want the object as a whole in the alpha then set the options to Constant Value and set it to 255. Also on your surfacing since you have and outer and an inner surface set the outer to a Refraction Index of 1.0 and inner to 1.4. Also get rid of double sided since you modeled both sides already. Also since you are using GI and refraction will cover most of the sampling try these values: IB 2, RPE 24, SBR 12, Multiply 25%. This will speed up the rendering a lot with very little loss of final quality.

-M

rcallicotte
02-17-2015, 09:32 PM
That did it, Sense - playing with the Alpha Channel. I set it to constant value of 20. THANKS!

- - - Updated - - -

Sherak, I'll try this. Thank you!



First set your CS (ColorSpace) to sRGB to insure the correct colors from your textures. This will also fix your alpha output to linear instead of sRGB. Also your surface is 100% in the transparency and since your alpha for the surface is set to surface opacity it sees nothing for the alpha. The Alpha Value will show you how much the object is affecting the alpha and in this case it is 0. So if you want the object as a whole in the alpha then set the options to Constant Value and set it to 255. Also on your surfacing since you have and outer and an inner surface set the outer to a Refraction Index of 1.0 and inner to 1.4. Also get rid of double sided since you modeled both sides already. Also since you are using GI and refraction will cover most of the sampling try these values: IB 2, RPE 24, SBR 12, Multiply 25%. This will speed up the rendering a lot with very little loss of final quality.

-M

JoePoe
02-17-2015, 10:29 PM
Actually, the most direct, simple and (imho) accurate solution is to disable the Edge Transparency shaders and you're good to go. :)
(you have surfaces which rely heavily on Fresnel/glancing angles and then add on Edge Transparency which gets rid of the glancing angles.)

BTW: the scene opened with no nodes active....only 100% trans. Once turned on the alpha fell in line.... without the shader :thumbsup:. Also, fyi, when dielectric is used the layer based transparency setting becomes irrelevant.

rcallicotte
02-18-2015, 07:02 AM
Are you saying the Edge Transparency shaders are overkill? So...the other thing - is it true that the dielectric has no mix with the other shader settings? I had no idea, if so.



Actually, the most direct, simple and (imho) accurate solution is to disable the Edge Transparency shaders and you're good to go. :)
(you have surfaces which rely heavily on Fresnel/glancing angles and then add on Edge Transparency which gets rid of the glancing angles.)

BTW: the scene opened with no nodes active....only 100% trans. Once turned on the alpha fell in line.... without the shader :thumbsup:. Also, fyi, when dielectric is used the layer based transparency setting becomes irrelevant.

JoePoe
02-18-2015, 07:35 AM
Are you saying the Edge Transparency shaders are overkill?

Not as a blanket statement.... visually I think it does add something here, but, in this case, at least when it comes to the alpha... I would say yes. At least I think it's causing more problems than it's worth :).

no ET shader... 127076 127074 ... and sRGB 127075

(Edit: when using the edge trans shaders, changing the display color space to sRGB did get something to show up... but it didn't save.... for me.)



...is it true that the dielectric has no mix with the other shader settings? I had no idea, if so.

With any material node I believe all settings are overridden by the node EXCEPT bump.
When plugging in individual components to a Surface you can mix and match nodes with layer settings.
But still, a node will take precedence. Meaning a node plugged into a particular channel will not get a "boost" or anything more from changing the same setting out in the main panel.....i.e. 40% transparency in nodes and 40% transparency in layers does not equal 80% (or 16% :hey:) transparency.... etc.

rcallicotte
02-18-2015, 08:26 AM
Thanks Mr. Poe. I had no idea there wasn't a mix between the material node and shader settings.

I like the results you showed here and this means more experimentation! Thank you!!