Annoying white PNG edges

[Woz]

Hi guys,
Well, I'm well in to the task of trying to find/make the very best general purpose tree for animated fly-arounds on my big landscape models.

Only problem seems to be, the contender that appeared to render quite well up close, appears to "frizzle" from frame to frame when it's in the far distance.
This used about 100 branch clusters each having 13 rectangular flat pannels, each with a "projected" PNG of a leaf sprig.

So I thought, maybe create just 100 or so "branch end"components, with a more "bushy" PNG projected onto a fairly basic (7 triangles) umbrella sort of shape. Then using just 100 or so on for same tree.

Unfortunately for whatever reason, I now get a stark whte edge around the leaf-edges on each PNG pannel.
I've even gone back to photoshop many times to make sure that the "clear" areas are totally clear with absolutely no semi-transparent areas, and ultra-crisp borders between color & clear.

Remembering how well a really nice Split-leaf Philadendron I downloaded rendered, I've done a comparison model of just the two together.
As you can see, the Philly looks crisp and sharp even just in Sketchup, but My Branch "Clump" displays an annoying white edge around where the PNG's colored parts meets the clear.
Renders the same too, in all render modes.

Both appear to use "profected" PNGs, and the materials properties of the two look quite similar.
I've also tried to post the SKP file as well (only 245k and zipped) several times but get an "Internal server error" message.

Does anyone have any thoughts on potential causes?

[Woz]

Trying to add the associated Sketchup test file again

here goes.

Test1.skp

(286.68 KiB) Downloaded 596 times

[Fletch]

The leaves with the white edges are just too low resolution to render that close up. Use a higher quality/resolution image of the leaves.

[Woz]

Hi Fletch,
I first thought that might be the case, so I also did aversion with a 1024 wide pixel png.
Same thing happened exactly.
Currently, it's actually a little larger than the Philadendron leaf PNG file.

In the interim since posting this, I have just taken the mapped image from the left one and replaced it with the PNG from the other.
Renders just fine-o-rama.

So... it really does point to some sketchup/twilight setting that I'm not aware of.

[Woz]

oh, and here is the pic.

[Fletch]

1 - I tried what you suggested (if I understood correctly) and I still have the white around the edges of the leaves.
2 - Painting plants with semi-gloss template will lead to big render times in Easy 1-7 settings. It's ok for Easy 9 or 10.

[Chris]

Here is what I think:

The transparent pixels in your image are white. They are transparent, so you can't see them, but if you could, they would be white. SketchUp uses smoothing (linear interpolation) when displaying textures so it is interpolating between the white of the transparent texture and the green of the leaf along the edges. You need to make your transparent pixels black or dark green or something more suitable for your image. Like this (I realize that you can't actually see the difference Download the image and try it!):

test.png (118.87 KiB) Viewed 12921 times

It looks better in SketchUp and renders better too.

[Woz]

WOW WOW WOW!!!!!!

THANKS CHRIS!!! (caps off now please..).

I LOVE it when people explain something new to me!

That's just the thing I was needing to hear. Certainly not something I was aware of til you explained it to me.
Now, just for the future, how do I make sure of this in either Photoshop or Gimp (I'm now hunting all through Photoshop to see if I can deduce what function might show me this difference - hmmm... Infa-red specs perhaps?).
*Also just tried opening the file in PS, reselect and save the outline, flattening the image (the clear parts turning white), replacing the white with black, re-cut out the clear area, then saved again. Still has the white edge though.

S0... just for the future... how did you check this? and more importantly, how did you do it?

I'm just as excited as anything to get help in licking tis dilemma!

Thanks again Chris!

Cheers,

Woz B.

[Woz]

Also, just noticed Fletch, while testing out YOUR PNG, the edges - while at lest not white - turn out a pale green. Would I be right in assuming this is just the reminants of the original colors that surrounded your leaves?

[Chris]

I had a hard time getting it to work too.

Here is what I did in GIMP (no idea how to do it in PS):
Open the image
Add another layer underneath the first.
- sample the green and paint the new layer with it
Select the original and do "Alpha to Selection"
"Merge Visible Layers"
Add Layer Mask -> Selection
Apply Layer Mask
Save as PNG
- Important: In GIMP there is a checkbox option to save transparent colors. Make sure it is checked!

Reimport into the SketchUp material and it should work (did for me).