2d image problems

[Thom]

Hey!

I'm using SketchUp 6 Pro with the SkIndigo 1.0.1 exporter.

I'm having a problem with two plant materials (2d images). I've placed two different yucca plants (completely cropped) in my latest design. One renders without any problems, but the other prompts an error when Indigo attemps to load the material.

The funny thing is, is that both images render fine in other SketchUp plans.

Here's another issue: When I import 2d trees (with transparency masks), they show up in SketchUp, but they don't show up in the Indigo render. When I managed to get one of them to show up in a render, the transparency mask showed up black (the mask's original colour) and the shadow was rectangular. I'm aware that Indigo does not have a raytracing feature, but I've seen Indigo renders with 2d trees. Is there I way I can get 2d trees with transparency masks to show up in an Indigo render?

Thanks in advance.
Thom

[Kram1032]

Lol.
BIIIG Confusion
Indigo does not have a way to NOT use ray tracing
more precisely, it's unbiased ray tracing.

Well, the problem is this:
Indigo simply ignores the alpha channel. Instead, you'll need to blend your texture with a null material and an alpha map. (Which you might be able to extract from your alpha-channelled image)

The one, that doesn't load. Which format is it and how many channels does it have? I don't think, it's the case, here, but just as an example: Indigo can't load single channelled 8-bit images (= grey scaled images). Indigo will think, it's poison

[Thom]

Should it matter what it is? I mean, it renders in every other plan. (It's a PNG with a transparency mask, but that shouldn't matter because it's manually cropped anyways)

And how do I "blend a texture with a null material and an alpha map"? I understand what you're saying, and I know how to blend, but I'm still confused.

Regarding my raytracing comment - I was in dire need of sleep (I still am), so try to ignore that.

[Kram1032]

It should matter, yes, but apparently, it does.
Ono simply didn't implement some kinds of image-support.

JPGs should always be fine as long as they're not 8-bit.
PNGs should work with the same limitation.... And I think, they also need to be in the correct colourspace (The one, that's optimized for monitors and not for high-quality prints)

Basically, the limitation is:
- Correct Colourspace (If you tweaked the image in photoshop, it might have changed)
- 8-bit or 16-bit per channel and three or four channels (RGB or RGBA, NOT just one "grey" channel, NOT Lab and NOT CYMK/CYMKA)
- Alphachannel will be ignored. (Though, Indigo can still read the information...)

- Instead of an Alpha channel, you need an alpha-texture (as you already have an alpha channel.... maybe, you find a way to extract it, for example like this: (Example is for Photoshop, but you should be able to do the same with the GIMP or any other program of this kind)
You need four layers.
- Lowest is black and switched to invisible
- above that, there's your image with alpha channel (visible)
- the two above these are white. One (which one doesn't matter) with blend mode "Luminosity" and the other one with "Colour"

Then, you hit Ctrl+Shift+E (in Photoshop) and after this, you make the black layer visible and merge the two remaining layers (Ctrl+E)

Now, you should have a greyscaled but still 3-channeled map, which visualizes your Alpha as Black = transparent and White = solid.

Use this as an input for the blend between the textured material with the original Image and the NULL material.

Shadows may still render solid, where the pic actually is transparent. If that's the case, you need to switch off BiDir. Then, the problem should be fixed

[Thom]

Thanks. I'll give it a go when I have the time.