Render data disappearing in PNG format because of Alpha contribution

[dseal]

All of the sudden any shader set with an alpha contribution of zero won't save in PNG format. It renders fine and saves as a jpg but is blank when saved as a PNG. Shaders with alpha of 1 are fine. The Alpha channel normal. How do I get all of my image to save regardless of its alpha? Help!

[thomthom]

Re: Render data disappearing in PNG format because of Alpha contribution

When you have alpha layer enabled in the VFB channel pngs will be exported with transparency. If you don't need it as a separate layer then turn it off. Or save out in another format, like bmp and convert into PNG later on.

[dseal]

Re: Render data disappearing in PNG format because of Alpha contribution

how do I disable my alpha layer? My pull down menu is set to 'RGB color', the 'alpha' and 'Monochromatic' buttons are off.

[dkendig]

Re: Render data disappearing in PNG format because of Alpha contribution

This will look a bit different in 1.05 releases, which I'm assuming is what you're using since you're posting in the rhino forum. It's in the same section of our render options though.

[dseal]

Re: Render data disappearing in PNG format because of Alpha contribution

I need the Alpha in the png and the full rendering. It worked before. Is there another setting that could be causing this? Maybe I changed something accidentally to cause this...it's the only thing I can think of other than a bug.

[thomthom]

Re: Render data disappearing in PNG format because of Alpha contribution

I've never experienced it working any other than this. But I've been using VfSU - not sure if there was a difference in VfR. But rendering PNG with transparency has always made my diffuse PNGs transparent.
When I need transparency and the full background I just save out in another format.

[dkendig]

Re: Render data disappearing in PNG format because of Alpha contribution

I'm going to guess that you opened the image in something like the default windows preview and fax app, saw part of the render was missing, and started to freak out? If you have a .png image with alpha, and you open it in that program, anything that has alpha won't show up. Try looking at the render in a web browser, photoshop, etc. Anything other than whatever the default image viewer is for your operating system.

[thomthom]

Re: Render data disappearing in PNG format because of Alpha contribution

You don't see any more when you open in Photoshop, you only get RGB channels - no A channel like you do with some other formats.

[dseal]

Re: Render data disappearing in PNG format because of Alpha contribution

Thanks for the help guys but I think I figured it out. I should be saving in Targa. It saves the alpha and the whole rendering. I knew it was something simple.