Hi
I am new to Houdini, and I was wondering if it was possible to make an object glow, and if it is, how?
Specifically, I am attempting to create a ‘lightsaber blade’ effect.
As I said, I am just starting with this program. (So far it looks really good.)
I tried placing a light source over an object and strecthing it so that it was the same shape, but it doesn't really work; the glow shows up on other nearby objects, but it cannot be seen around the object itself.

Thanks!

…if you're after something like a lightsaber effect (and frankly who isn't ) I'd do it in comp - you'll have way more control…that's how ILM rolls…

Thanks for the reply, but could you possibly clarify a bit? I do not know what you mean by ILM or ‘comp’. I am new to this entire type of program.

Thanks.

comp = compositing = putting bunch of pictures into one piece.
ILM = industrial light and magic = star wars = yoda

Ahh. Thanks.

I think there is a free tutorial on the cmivfx.com website for Houdini that shows you how to do this…

Cheers,

pete rB

yep:
Tutorial 18: Houdini Halo Image Based Glow

http://www.cmivfx.com/tutorials.asp [cmivfx.com]

So I have to make two separate images, make the one that will be the blade glow, and put them back together?

No, you should be able to use the Alpha channel of the blade image and use the compositor to make it glow. I haven't actually done that tutorial but that's the essence of glows…

Cheers,

Pete rB

How do I do that? I apologize if this is a dumb question. As far as I see, I can only open .jpeg files in compositing mode. Do I have to save my project as one?

Hi Elias, I think that you are “really” starting on CG, not just Houdini.

What they mean by compositing is this:

- On a image editing program like Photoshop, you can use layers of images. Imagine you take a photo of a friend, and you would like to put his head on a dogs body. In an image editing software you would first put a dog's picture in your canvas, then you could cutout your friends head from photograph and paste it on top of the dogs head. Just like you would to on real life with printed photographs and some glue . But lets say that you didnt like the dog picture you used, you would have to start all over again because you ruined both your pictures. In graphics software we could have pasted the head in a layer above your dog picture. That way we would not ruin the original, if we decide to change the dog that is on a layer undeneath the head we can, because they are 2 separated things. That is compositing, or a virtual colage.

- With houdini compositing tools you can do much more than paste together images, we could for example animate the layer that is above… like a video of a shrinking head on a dog And since is all “virtual” you can later on change something in the video if you wish.

- As for the glow, you could from your rendered image of the lightsaber put the glow on another layer on top of it. Why? Maybe later on if you decide that you want to change its color or intencity? Just change it in the above layer!

You will need a lot more reading for making good compositings of pictures, rendered images, effects, etc. Search for alpha channel, compositing, layers in google or in books at Amazon.com

I hope I've helped and not confused you even more :-)
Cheers

and here are some videos for compositing in Houdini:
http://odforce.net/downloads/videos/v6/compositing/ [odforce.net]

and another tutorial here:
http://www.sidefx.com/index.php?option=com_content&task=blogsection&id=14&Itemid=132 [sidefx.com]
see Compositing CG Elements

Thanks a lot.