Alpha texture problem


(Zugzug) #1

Greetings!

I have strange problem with setting alpha textures with alpha layer (PSD,TIF and others). It don't read alpha channel anymore... Just all the model goes alpha... Models what worked before also don't work if i upload them again with old fine zip file what was used before and work fine like this one https://sketchfab.com/models/92b1c86d8a2f4023afd7f09671cf0013

http://take.ms/lDVvP
http://take.ms/wZqd2

Need HELP asap, trying to publish model for Halloween contest! :rage:


#2

Looks like you figured it out?


(Electrocactus) #3

Yep, I have the same problem, no alpha map supported. On my last models, everything was ok..


#4

@electrocactus Are you talking about the trees on your Halloween Scene model?

It looks fine to me after you put the texture in the right slot:


(Zugzug) #5

I just forced to use simple rgba png textures, tif and psd still don't want to use alpha layer. Also i noticed if i trying to upload textures from 3d settings - manage textures, it don't see my tif and psd textures, but tga textures converting to png if i import them.


#6

Right - We convert TIF to PNG and don't support PSD at the moment.


(Electrocactus) #7

lol, my test scene :smiley: nono. I did a lot of crazy tests, its all messed up right now.
+1 what zugzug said

I can get stuff done with png, but Tiff with alpha channel works better usually.


#8

Ok, I still haven't seen a model with broken alpha, so if you can give me a URL where it's not working as expected, I'd love to help :smile:


(Electrocactus) #9

Ok, from my part, I can say: I kinda messed up and all is good now. I just add png textures with transparent parts and add them in transparent channel. So, all works for me! No complaints from my end :smile:

I think, what zugzug is trying to say, is that, few months ago, TIFF and PSD worked. So, the way he did transparent textures was: diffuse map and in 5th channel, there is a black/white alpha. Now, you can't do it that way, because you can't use TIFF and PNG does not support that.


#10

Ah ok, I see now.

PSD was pretty difficult to process, so we dropped it for now. Maybe @marc has some more insight?


(Mrchlblng) #11

@zugzug, @electrocactus I am a bit confused with your issues here (if you have any?) so let me try to clarify how we process images.

We currently rely on the browser to decode images natively, which means that all images will have to be either jpg or png:

  • at upload:
    • any jpeg/png image will be unmodified (except for metadata being stripped away)
    • any other format that we support (to name the main ones: tga, tiff, dds, psd) will be converted to a png image
    • we recently changed the whole image processing code to have a better "premult alpha" strategy for our needs (to avoid going balck for pixel fully transparent)
    • we import all images we find in your upload
  • in the 3d settings:
    • we rely on the browser so we only support jpg and png and we added tga as it was requested by artists

The bottom line is that we don't have the same format support depending on when you want to import an asset which is not very user friendly, I agree.

Regarding psd, it's not clear to me if we really support the format well (and I'd probably say that we actually do not support it well). If you have specific issues with psd, please let us know so that we can try to improve it.
Tiff should however be well supported.

Finally, if you currently reupload your model, you'll lose all your previous textures/materials but this is going to change very soon so that should make the import process for not browser-friendly formats easier!


(Electrocactus) #12

basically, the issue was: We always used TGA textures with alpha channel and in 5th channel, was information for transparent/non transplant parts. I did it for last 2 models, it worked, now I tried and it did not work, das, I asked question here and you answered. That is all!

However, if TGA textures are not supported, how can I make maps like: metalness? It has gloss map in alpha channel. And many other maps, that needs 5th channel. PNG and JPEG does not support that function!

About mesh re-upload - Yes, yes and YES! :smiley:
It's really frustrating, that after mesh update, you need to set up lights and everything from scratch!


#13

For metalness we expect a linear grayscale texture; black (0.0) for non-metal and white (1.0) for raw metal.

I'm pretty sure we've never supported a 5th channel.

Full details on our PBR implementation here: https://help.sketchfab.com/hc/en-us/articles/204429595-Materials-PBR-