Indigo Renderer Forum

Hi all!

I was wondering if someone had a good link to a tutorial that would explain how to use Black & White clipping masks in Photoshop.

I've recently bought some 2D trees with the corresponding Black & White masks, so I can integrate them nicely into a 3D render.

But I'm struggling with telling Photoshop to treat white as transparent, black as solid, and grey shades as anti-aliasing.

Many thanks, keep enjoying Indigo !!!

I think I found a nice and easy one :
http://www.lunacore.com/photoshop/tutorials/tut003.htm
Cheers !

To clarify, you want Layer Masks, not Clipping Masks, in Photoshop. It's basically a BW layer that you can paint on to make parts of the layer invisible/visible.

- Copy the black and white mask.
- Press Q to go into Quickmask mode.
- Paste the BW mask (it'll show up red and transparent over your image, that's fine)
- Press Q to exit Quickmask mode. The part that's being masked should be selected now.
- In the Layers panel, right down between the fx button and the filter/layer adjustment button, click on the Add Layer Mask button. Your selection should be turned into a black and white layer mask. If it's inverted, click on the layer mask and hit Ctrl + I.

Great!

Thanks for your reply, I'll try this tonight and keep you informed!

Cheers !

If you're using it in Indigo, you can just set the black and white image as a mask/clip for the material and Indigo will clip it properly.

Thanks for your replies guys!!

StompinTom -> your tips helped me greatly, thanks!

Soup-> thanks for this tip, I'll try it also, soon!

When I first tried indigo, I was expecting the ability to render to save as a PNG with an alpha channel.. Until that happens, I'll just use the magic wand tool to remove the black parts in photoshop.

I thought Indigo was able to render your scene as a BW mask by clicking "Alpha" (in Blendigo)

madcoo wrote:I thought Indigo was able to render your scene as a BW mask by clicking "Alpha" (in Blendigo)

Yep and that's the way you should do it. Using the magic wand could mix up dark parts of your rendering or shadows and interpret them as background. It also doesn't work for scenes with the sky system or scenes where there are complex objects against the background, such as trees (have fun magic wanding all those tiny spaces between the branches and leaves).

madcoo wrote:I thought Indigo was able to render your scene as a BW mask by clicking "Alpha" (in Blendigo)

It does and I have used it successfully in an indigo + photos composition project. It works well.

Only one thing bothered me, which was the need to render normally first and alpha map second. I believe I requested at the time that both be done simultaneously. As far as I know that request was ignored.

Or better yet, just render to a PNG with an alpha channel. By for the most straight forward and easy solution. I used to use yafray before indigo (4+ years ago) and it supported this.

You're right, and the request is on the list. I think at least the alpha render will make its way to the Indigo GUI.