topic Re: Glow on existing texture in 3ds Max Shading, Lighting and Rendering Forum

Glow on existing texture

jmarchik — Fri, 20 Apr 2018 02:09:42 GMT

I've got an image sequence that consists of red, white and blue. The white portion moves and wipes from the red to blue. I'm 99% sure I can't do this but I thought I'd ask, but can I add a glow to just the white portion?

Thanks.

Re: Glow on existing texture

madsd — Fri, 20 Apr 2018 05:25:32 GMT

Sure, you can mask out the 2 other colors with OSL nodes in 2019 and just use the white as a emitter guide.

If you dont use the newest version of max, use a post editor to generate the mask.

Re: Glow on existing texture

madsd — Fri, 20 Apr 2018 05:59:18 GMT

As seen here:

Load a bitmap, split the second channel out with a vector component and pipe to emission.

Done.

If you need a certain spectrum and not a fixed color you can use a range node to define the spectrum. Like if you wanted some kind of Roto going in a gradient.
There is also a Chromakey which can do realtime greenscreen subtration in the viewport/render.

Re: Glow on existing texture

madsd — Fri, 20 Apr 2018 08:35:54 GMT

Forgot to mention, if you use Arnold, you can do it easily as well in previous versions of max, since Arnold has core function maps as well.

Re: Glow on existing texture

jmarchik — Fri, 20 Apr 2018 13:40:06 GMT

Thanks for the reply, using 2018. Can you point me towards some info on how to execute your solution? Would love a chance to learn more and you've exceeded my abilities. 🙂

Edit: Attached you will find the animated texture I want to add a glow to, just the white though.

Re: Glow on existing texture

madsd — Fri, 20 Apr 2018 14:28:40 GMT

Sure,

- So I first converted your mp4 file into jpg files around the area where the white bare is visible.

- Loaded the image sequence to a bitmap node.
- Added a user data float node and parse bitmap though this.

- Parse the User data float into Input on a Range node.
- Raise output to 2.

- lower output min to a negative value to crush the red and blue out of the space, - 4 seems fine.

- Added the output of the range node to Diffuse, obviously, you want to add it to the Emission node instead.

Now we have a version of the animated texture with blue and red excluded, one we can pipe to the emission as shown above in the previous reply.

Do note you have a glitch in the texture flip, the red shows after white passes, so you need to fix up some keyframes.

Ideally you would prefer to do this kind of animation directly in max instead, much more flexibility.