Transparent textures in Blender

[Trylon]

I'm afraid I must agree with everyone else here: try PNG textures first.
I must confess that I did not use anything else than PNG textures to check if that transparency works, and I never tried TGA.

I just checked to see what the plugin exactly does - It uses the blender texture file to read inevery individual pixel - builds up a raw rgba picutre from that, and potentially compresses it with DXT-5 (DXT-1 only in case of no transparency).

So as far as I can see, it must be a blender thing - appearently blender does not pass s TGA alpha information correctly to the plugin....

[Branan]

that's... wierd. Really wierd.

Blender supports TGAs, and if you're just getting the image information from Blender, you should be able to get that just like everything else...

I'll take a look at the BPy stuff for images, and see what I can dig up.

*EDIT* looked at the BPy image stuff... can I assume you do this:

[x,y] = img.getMaxXY()

for 0 to x:
for 0 to y:
imbuf[x][y] = img.getPixelI(x,y)

Or something similar? That'll give you imbuf[x][y][0] = r(x,y); imbuf[x][y][1] = g(x,y); imbuf[x][y][2] = b(x,y); and imbuf[x][y][3] = a(x,y)

I think it will, anyway... I'm not really sure how Python handles multi-dimensional arrays, if it handles them at all. But you should be able to do something like that.

Once that's done, you just do whatever else needs to be done on the image.

[Robert The Rebuilder]

OK - I've taken the suggestions, and did some experiments, and here's what I've found:

- Simply changing the texture file format to PNG: still opaque
- Using the 6/2/2006 code base (last one before refactoring): still opaque
- Exporting using the "Generate Release" option in old code base: object not visible
- Exporting using the "Generate Release" option in new code base: object is transparent, but is drawn first so that no other object appears on the other side
- Add a second object that uses the texture, then export using "Generate Release" option in old code base: TRANSPARENCY!
- Add a second object that uses the texture, then export using "Generate Release" option in new code base: TRANSPARENCY!

So, the transparency works only if you have more than one object using the texture AND you select Generate Release. Without generate release, the texture is in the DirectX A8R8G8B8 DDS format, while although it does contain the alpha values (I've verified this in PRP Explorer), the Plasma engine only makes it transparent if it is in DXT5 DDS format.

Oh - and I forgot to mention: you need to delete the _TexCache when you change to Generate Release; otherwise, the cached texture is in the wrong DDS format.

[Trylon]

[quote="Robert The Rebuilder"] OK - I've taken the suggestions, and did some experiments, and here's what I've found:

.....

- Add a second object that uses the texture, then export using "Generate Release" option in old code base: TRANSPARENCY!
- Add a second object that uses the texture, then export using "Generate Release" option in new code base: TRANSPARENCY

[electroglyph]

I haven't programmed in decades but when I did have problems with matrices it was usually because I forgot that zero was a number. If one textured object won't work but the second works with two then you probably have a flag or array size statement that needs to be changed from n=x to n=x+1.

[Robert The Rebuilder]

[quote="trylon"] I didn't encounter that before.... were you able to check the layer settings (with prpexplorer) for your layer in both instances? They should be (kinda) set to transparency in both cases.

[Trylon]

Robert,

to your point 1:
Added that to the plugin yesterday. Along with what I have on that other thing I was working on

to your point 2:
Unfortunately, I don't know squat DrawableSpans yet, so... everything I say is basd on guesswork. - We could however save transparent objects for a tird object pass, so that they get processed last in the plugin. I don't know how to tell the plugin to make a separate drawspans but maybe someone else does.

On a side note:
Would this Drawablespans thing also account for this situation: ? (had that once) - I had a plane with a drawing and a lot of transparency hovering a few centi-/millimeter above around on a solid floor, but when it was loaded, the solid floor was made transparent too on the places where the plane should be transparent

[Robert The Rebuilder]

Trylon:

From your description, it does sound like an ordering problem. The transparent plane above was rendered first; at the time, the solid floor below was not yet drawn, so you probably saw through the floor (which was rendered second, but behind the transparent plane). If the transparent plane was drawn last, then you would have seen the solid floor.

I'll see what I can do, since I'm pretty familiar with spans from the refactoring.

[Robert The Rebuilder]

This issue has been fixed - see the post at Alcugs:

http://alcugs.almlys.org/forum/viewtopic.php?t=215