Tutorial: how to use 32-bits images in a material Diffuse channel

Fonte Boa · 03-01-2013, 05:14 PM

How to use 32-bits images in a Wings material in the Diffuse channel so that, after UV map the mesh, you can see the transparent areas defined by the Alpha channel.

A 32-bits image has 8-bits to red channel, 8-bits to green channel, 8-bits to blue channel and 8-bits to alpha channel: this last one, define the transparent areas.

At the begginning of video, i used Photoshop to select the image white area, then i inverted the selection and created a channel based in this selection (alpha channel). I saved the image in TGA format, but i think TIF, BMP and RLE store alpha channel too. The rest you can see in video.

Any feedback is appreciatted.

oort · (This post was last modified: 03-01-2013, 05:35 PM by oort.)

Fonte Boa,
Very nice tutorial. Good that you showed how to use AutoUV in the process. I am usually lazy and just use the Snap Image tool... Smile

I was wondering why you divided the plane at first then saw you bend the leaf... Very nice... Cool

If newbies are wondering, you can use Gimp to add the Alpha channel if you do not have Photoshop. I know that PNG images work as well. Good quality image at smaller file size than BMP.... Smile

Thanks again Fonte Boa,
oort

Fonte Boa · 03-01-2013, 05:47 PM

Thanks for the feedback! Smile

Oort, please correct me if i am wrong, but (i dont use Gimp) i am not able to save a PNG with an Alpha channel... I've just tried here in Photoshop without success... Maybe i am missing something...

----

There was a uv mapping error of mine in the anterior video: it is possible to observe the leaf images at each side of mesh are flipped and they arent coincident. Sorry for that.

But it is easy to correct: just change to Body mode, call .UV Mapping. to open AutoUV window and there, press space bar to deselect all, and after this change to Body mode (in this window) and click on the leaf image. By doing this, you will be selecting ONE of the two blocks that are there. Then, just right click and call Flip and then Horizontal. This is enough to correct the problem. Smile

oort · 03-01-2013, 09:34 PM

Fonte Boa,
I just tested creating a PNG with Alpha using Gimp and it worked fine...

Select white area around leaf shape with Fuzzy Select Tool.
Layer > Transparency > Color to Alpha.
Save as PNG.

In Wings3D Outliner > RMB Texture > Show... See the checkerboard alpha background. Maybe there is some option you have to set in Photoshop to make it work right???

oort

Fonte Boa · 03-01-2013, 09:43 PM

(03-01-2013, 09:34 PM)oort Wrote: I just tested creating a PNG with Alpha using Gimp and it worked fine...

Oort, when possible, could you please attach this png file here at forum or post it at imageshack (or anywhere)? I would really like to open it in photoshop to understand the situation: thank you very much for the tip! Smile

Usually at work i just work with tgas, tifs and jpgs.

Fonte Boa · 03-01-2013, 10:13 PM

I've just downloaded and used it in Wings successfully.
I'll study it in Photoshop to learn how to produce 32-bits PNG. Thanks, oort. Smile

Ran13 · (This post was last modified: 03-05-2013, 04:17 PM by Ran13.)

As always, in AdobePS, if you want to use your images in other apps, always use the "Save for Web..." option. This option will give you the correct options in AdobePS for a proper 32b PNG.

(It'll list "PNG-24", but just make sure the "Transparency" box is checked)