Using alpha of one layer to mask another layer

Using alpha of one layer to mask another layer...

Is this possible?

I want to make a dust particle effect inside of a lightbeam, so that the dust is only visible within the light beam.

(Light beam(s) on Top layer, dust covering complete bottom layer)

But I also have Layers with content below and I don't want those to be affected. So i can't use the "destination out" blend mode.

Any Ideas?

You can use destination out but you should use the force own texture for the layer.

Made this one not too long ago for someone else

OK this one helped me...(Thanks a lot so far) so I have to do it on the same layer.

Still have one problem:

The masking of my Lightbeam now works, but only inside the boundaries of the image itself. This would mean to accoplish my desired effect I would need a huge Transparent area in my Image that covers the whole layout, which would waste a lot of memory.

Any Ideas on that as well?

you'd only have to mask the viewport, not the entire layout.

If you use one or more instances (depending on how you've set things up) of a transparant tiledbackground of 2x2 for that it should work.

I'm not even sure all has to be covered if you set things up properly, but if you have to?

yeah you're right, the tiled background would do the trick, I didn't think of the possibility to use more than one object for masking my dust.

Thanks a lot

Thanks again for your Help, you can see the Result here if you want:

www.againstgravity.de (choose Testlevel)

Controls:

When hitting LMB the ship will rotate towards the Mouse Cursor and give thrust relative to the distance ship/cursor.

It's best to place the cursor over the ship, press and hold LMB and then move the mouse up slowly to get a feeling for the controls.

While LMB is pressed you can throw bombs with RMB.

While LMB is released you can shoot lasers towards the cursor.

What do you think?

Wow! Looks gorgeous.

That is very good.

Looking gorgeous, glad I could help!

Really great-looking game! Definitely one of the higher quality C2 games I've seen!

Thanks to you all, means a lot to me.

I really do love the dust particles in the light effect.

I've been trying to do something similar myself, but I just can't get this destination out setting to do what I want.

How exactly does the transparent tiled layer need to be set up to get rid of the boxes appearing around my particle sprites?

The trick is that there are no actual particles.

I have ONE Layer with "force own texture" EDIT: And set to "Additive"

In This Layer are (from top to bottom)

• the sprite containing the lightbeams with tiledBG objects around to mask the rest of the viewport
• two huge rotating tiledBG objects containing the dust texture along with dust particles
• additional green dust sprites for the collectable crystals

That's basically it

H*ly shit that game looks nice. Hope to see more of that soon.