topic Render image with transparent background in Maya Forum

Render image with transparent background

Anonymous — Thu, 13 Feb 2020 21:46:30 GMT

Hello everyone,

I'm trying to render weapons for an inventory system in Unity, but I don't want to render with black backgrounds. I've visited quite a couple of forums, and the answer was to just remove the black by hand. I'm rendering a transparent glass material, and need to render with no background. How do I do this?

Re: Render image with transparent background

trs_andre — Fri, 14 Feb 2020 01:41:46 GMT

Hi!

If you save your rendered image with alpha (for example in PNG), it has transparent background 😉

Re: Render image with transparent background

zewt — Fri, 14 Feb 2020 01:50:18 GMT

Sort of need to say what you're rendering with 🙂

If you're using Arnold, that's a bug. Arnold always renders opaque PNGs. To get a transparent background you need to render to TIFF or EXR or some other format and then convert manually. It makes rendering simple transparent sprites and icons way more annoying than it should be.

Note that if you're using transmission on that bottle, you're not going to get real transparency there no matter what you do, since transmission can't be done with simple alpha. If you want transparency there, be sure to only use opacity, not transmission. For the specular to work properly you'll need a premultiplied format (TIFF will work, make sure "unpremult alpha" is turned off in render options) and it'll only work in software that understands premultiplied alpha. It's definitely possible to support it in games, I don't know about Unity specifically though.

Re: Render image with transparent background

Anonymous — Fri, 14 Feb 2020 10:49:56 GMT

I am using Arnold to render. Should I switch back to the Maya Software? I'll use the real opacity on the clear glass. Thanks for your help!

Re: Render image with transparent background

zewt — Fri, 14 Feb 2020 10:54:00 GMT

I'm not sure there's ever a reason to use Maya Software at all 🙂 Just switching to TIFF instead of PNG might solve your main problem of getting a black background (assuming you were using PNG in the first place).

Re: Render image with transparent background

Anonymous — Fri, 14 Feb 2020 10:57:49 GMT

I did render the images as png's

Re: Render image with transparent background

mspeer — Fri, 14 Feb 2020 15:28:21 GMT

Hi!

Please use "tif" as image format to save a proper alpha channel.

Re: Render image with transparent background

Anonymous — Fri, 14 Feb 2020 16:58:22 GMT

Okay I'll try it!