"Falloff" feature in Iray???

JeffG

Is there any way to do a shader falloff effect in Iray? I want to be able to transition from one color to another (or one texture map to another) based on the angle of the surface.

Example:

In the above, the color transitions from red to green based on whether the surface angles toward or away from you. A lot of very cool effects can be achieved this way.

I know that we have a fresnel effect in the options of the glossy and top coat components of the shader - but I am looking for some way to modify the color.

I have tried bringing the Ubershader into Shader Mixer but I am bewildered by the array of options...

Any help would be greatly appreciated!

(Forgive me for asking again. I asked previously in another forum and recieved some helpful pointers but the answers lead me to a dead end.)

Richard Haseltine

You could use the Layered Image Editor to add a solid colour layer with a black-to-white gradient as a mask.

Oso3D

My shader pack has an outline preset that uses a glancing function to shift opacity. You could do similar for color.

(if I ever do a WTP4 I might do something like you describe)

JeffG

Richard,

I'll check that out - thanks! Can the gradient mask be modulated by the surface direction?

 

timmins.william,

You deserve some kind of "Forum User of the Month" award.

Oso3D

Aw, thanks.

The glancing tint function is strictly camera based, but it's one of the very few functions that are (in MDL/Iray).

If you want more control you can use Normals, which are absolute; my snow shader might do the job, since you can can modify which Normal axes are considered.

 

Richard Haseltine

JeffG said:

Richard,

I'll check that out - thanks! Can the gradient mask be modulated by the surface direction?

 

timmins.william,

You deserve some kind of "Forum User of the Month" award.

The mask would be an image file, if youi want soemthing more dynamic then you need to look at a shader based approach as timmins.william is suggesting

JeffG

Thanks for all you help. I think I'm getting close...

Forgive me for being dense, but how to you add a gradient ramp (with a glancing tint function) mask in the layered image editor?

Richard Haseltine

JeffG said:

Thanks for all you help. I think I'm getting close...

Forgive me for being dense, but how to you add a gradient ramp (with a glancing tint function) mask in the layered image editor?

You don't, that was in Shader Mixer.

Oso3D

Yeah, there's a Shader Mixer brick called Glancing Tint. I forget what subdirectory it's in, Shader Mixer is a Lovecraftian non Euclidean hell dimension. :)

I remember stumbling across it and going 'well, that SOUNDS interesting...'

JeffG

Richard Haseltine said:

JeffG said:

Thanks for all you help. I think I'm getting close...

Forgive me for being dense, but how to you add a gradient ramp (with a glancing tint function) mask in the layered image editor?

You don't, that was in Shader Mixer.

Richard, thanks for bearing with me. How do I do that in the Shader Mixer?

JeffG

timmins.william said:

" Shader Mixer is a Lovecraftian non Euclidean hell dimension. :)"

Boy oh boy! Is that the truth!

It looks like you must become one with the Flying Spaghetti Monster to begin to comprehend it.

I have downloaded your free shaders (awesome! thanks so much!) and am studying them intently.
Are there any good Shader Mixer tutorials you would recommend?

Oso3D

Nope. There are also no listings of bricks and what they do.

I pretty much had to examine existing shaders and pick through stuff that sounded right and see what happens. 

One tip: if you bring an Iray uber shader to shader mixer, only active brick sections are copied; this is an optimization to help it run fAster, I think.

so be sure to set values for emission or whatever to make sure that function is exposed in mixer version

DrHemulen

Oso3D said:

My shader pack has an outline preset that uses a glancing function to shift opacity. You could do similar for color.

(if I ever do a WTP4 I might do something like you describe)

Cool, that sounds like a good place for inspiration. Which shader pack are you talking about? I can only find the iridescent one on the DAZ market place? I also really want to take a look at your snow shader. I'm coming from playing around with the octane renderer, and thought that was complicated until I opened the DAZ shader mixer. Non Euclidian is a very good description.

rocthered_1819485

Oso3D said:

My shader pack has an outline preset that uses a glancing function to shift opacity. You could do similar for color.

(if I ever do a WTP4 I might do something like you describe)

Sorry where is this shader pack? I was struggling to find solution to opacity change based on viewing angle so badly!

Thanks!

Silas3D

Sorry to resurrect this thread but I'm currently experimenting with shader mixer and given the lack of a search capability for bricks, I can't find this `glancing tint` function...

Edit: not to worry - I found your iridescent shaders in the store, Will!

mark_z2487

Just came across this thread searching for 'fall off'

Does this work with opacity / transparency?

Too bad it is so difficult in Daz / iray, in 10 year old Max all of this is simple, they give you a little graph to show the transition amounts

Sevrin

It's just this

Inverse-square Law

santjaga1975

So. Anybody shows how to make this Falloff? Or nobody can not?

Thanks!

Richard Haseltine

santjaga1975 said:

So. Anybody shows how to make this Falloff? Or nobody can not?

Thanks!

Which? The original subject of the thread, colour varying by incident angle?

AllenArt

You can also sometimes get the same effect by switching to weighted mode and putting different colors in diffuse, glossy and top coat.

Laurie

santjaga1975

For example I want opacity through falloff. Like X-ray effect.