Author Topic: Alpha Channel PNG  (Read 14461 times)

hi there,

I want to ask, if there is a way to prevent alpha-channel form export to png?
I mean, I always get an (useless) Alpha in normal, diffuse and so on, that I do not need (just sometimes)

Is there a setting or something to tell B2M to not add an Alpha-channel, when exporting to .png or to delete it, if one is present?

Kind regards

Ok, so I think there is something "wrong":

1. When open a .PNG image in B2M, B2M "automatically" adds an alpha layer
(when opening the same .PNG image in let´s say Gimp, there is none!)
2. When saving bitmaps in .PNG format, B2M saves it with an alpha layer
(like I stated before)

I am not sure, but somehow this seem to affect the "intensity" of normal maps.
I get "pale" normal maps, that got nearly no effect (see attachments)

Nor1.gif = the "pale" normal map result from B2M
Nor2.gif = example of what it should look like (from "intensity" point of view)

Do I miss something here? Or is it kind of bug?

edit: (When viewed in B2M, the normal map looks fine, but not after saving!)

Best Regards

Last Edit: April 08, 2014, 08:18:17 am

Hi,

I can't seem to reproduce the issue. I supplied B2M a rust image with alpha and it treats the alpha as blank in the normal map creation. I end up getting a normal bitmap that has no alpha on export. Can you send me the image you are using?

Here is what I am getting from B2M export. The alpha areas of the original image appear as holes in the normal map as there was no data to use.

Cheers,

Wes

Integrations Product Manager / Training
wes.mcdermott@allegorithmic.com
Twitter: The3DNinja

Hey Wes,

here are the images, I used. But I get this issues with every image so far!
Basically put in "Cliff01_ori.png" into B2M and got the outputs.

Hope you can help...

Cheers!
Last Edit: April 08, 2014, 03:30:11 pm

Hi,

Hmm, I can't seem to reproduce the issue. Are you using B2M in Substance Player?

Here is the normal that I get.

Integrations Product Manager / Training
wes.mcdermott@allegorithmic.com
Twitter: The3DNinja

Hmmm, I just open B2M 2.2 Indie Version, drop diffuse tweak bitmap into and
that's mainly it. (Of course tweaking some settings)

I tested with the same texture, that I attached in my prev posting.
When I open this texture in Gimp, there is no alpha-channel - I got an option to add one! Why B2M say´s "Display Alpha Channel", when there is none?!

see B2M_adds_alpha.png = has no alpha-channel, but I can "Disable one" and diffuse+normal map are displayed bad!

When I uncheck this option, my normal map looks like the one, you´re getting - but when I save it, it looks different again (!)

Last Edit: April 08, 2014, 07:34:13 pm

B2M automatically stores the heightmap output also in the alpha channel of the normal map, in case you may want to use it for displacement or parallax. That's what you see in Player. Depending on which format you export to, that alpha channel will be retained or not.

Hmmm - but why does Wes get another "normal map version", than I?
Why "adds" B2M an alpha, where there is none?
Is it, because it´s .PNG or what?!

Strange...strange.. still can´t get normal maps!

Please have a look, again, not solved yet...

Hmmm - but why does Wes get another "normal map version", than I?
Why "adds" B2M an alpha, where there is none?
Is it, because it´s .PNG or what?!

Strange...strange.. still can´t get normal maps!

Please have a look, again, not solved yet...

Where did you see the option for disable alpha? Was that in B2M? I can record myself using B2M and exporting. I'm not sure why you wouldn't be able to get the same setting. I exported all maps and I don't get an alpha in the normal.

We'll get it straightened out :)

Cheers,

Wes
Integrations Product Manager / Training
wes.mcdermott@allegorithmic.com
Twitter: The3DNinja

hehehe ;)

I get the option, when right-clicking on the image

When I open "Substance Player 3.6" from C:\Program Files\Allegorithmic\Substance\Player\3.x and choose "Bitmap2Material_2_Trial.sbsar" and then drop the cliff-image into - everything is displayed ok, like I expect it to be. No strange "Alpha channels" or wrong normal map exports... but the "Trail logo", because it´s the trial version of B2M.

When starting B2M Indie from:
C:\Program Files\Allegorithmic\Bitmap2Material\2.x\substance_player.exe
I get no "trial logo", but this alpha-channel issue...


When I open "Substance Player 3.6" from C:\Program Files\Allegorithmic\Substance\Player\3.x and choose "Bitmap2Material_2_Trial.sbsar" and then drop the cliff-image into - everything is displayed ok, like I expect it to be. No strange "Alpha channels" or wrong normal map exports... but the "Trail logo", because it´s the trial version of B2M.

When starting B2M Indie from:
C:\Program Files\Allegorithmic\Bitmap2Material\2.x\substance_player.exe
I get no "trial logo", but this alpha-channel issue...

That is strange. I will check the indie version to see if that is the issue.
Integrations Product Manager / Training
wes.mcdermott@allegorithmic.com
Twitter: The3DNinja

When I open "Substance Player 3.6" from C:\Program Files\Allegorithmic\Substance\Player\3.x and choose "Bitmap2Material_2_Trial.sbsar" and then drop the cliff-image into - everything is displayed ok, like I expect it to be. No strange "Alpha channels" or wrong normal map exports... but the "Trail logo", because it´s the trial version of B2M.

When starting B2M Indie from:
C:\Program Files\Allegorithmic\Bitmap2Material\2.x\substance_player.exe
I get no "trial logo", but this alpha-channel issue...

Hi,

I just tried it on B2M Indie and I can't reproduce it. Please check this png. The height is placed in alpha channel, but on export, the alpha channel is gone. I opened in PS and there is no alpha channel.

You can see this happen in SD when you use the normal node. If you feed it a height map, it will produce normals with alpha that look like the results you posted. I think the same operation as Jeremie mentioned, is happening in B2M, but I can't get it to export the the alpha issue.

I'll need to ask the developers : ) I'm sorry I don't have an answer for you yet.

Cheers,

Wes



Integrations Product Manager / Training
wes.mcdermott@allegorithmic.com
Twitter: The3DNinja

Ok, I´ll be waiting - indeed very strange...

Ok, I´ll be waiting - indeed very strange...

Hi,

Great news, I have it figured out : ) I spoke with the devs and they found the issue.

The issue was that the version I am using is different. You are using the most up to date version and I was getting the incorrect behavior for the alpha. The heightmap is stored in the RGB channels and appears as alpha. You could export to a format that doesn't support alpha such as JPG, but this is not a good option for normals maps due to compression.

As a workaround, you can export to PNG and then use Photoshop or Substance Designer to remove the alpha. In Photoshop, you can do the following.

1. Open the PNG.
2. Go to Layer>Layer Mask>From Transparency
3. On the Layer, Shift+Click the mask to disable it
4. Right click the layer and choose flatten

In Substance Designer, I made a removeAlpha utility. You can input a color texture and it will remove the alpha and produce a generic output. You can use the output for normal maps or color images. For grayscale, you just need to convert to greyscale.

Cheers,

Wes


 
Integrations Product Manager / Training
wes.mcdermott@allegorithmic.com
Twitter: The3DNinja