PDA

View Full Version : quick node question



DrStrik9
05-29-2009, 03:29 PM
OK, getting the node concept through my thick skull is proving to be somewhat of a challenge. Doh!

I have a simple ball, with a low-rez image world image for reflections. I used alpha in 2 Gradient nodes with Incidence as input, to control the reflections and diffuse by the camera's incidence angle.

So my question is: how do I add BLURRING to the reflection using one or more nodes with this current setup (without using a bump, that is)?

Thanks for any help,
Michael

Kirdian
05-29-2009, 04:03 PM
Connect Reflection node (from Shaders/Reflection) whit Reflection Shading input. You can set Reflection Blur in this node option.

Tobian
05-29-2009, 05:25 PM
Ok.. Pretty much all of the options for the regular surfaces are recreated as node inputs:

However unless you plug a node into them, the old inputs work just fine. I.e. if you go to the advanced/environment surface properties and add reflection blur ammount, then it will work fine...

If you input a constant value node into the same input it will have the same effect. EXCEPT that with nodes they go from 0-1 - where Lightwave would go from 0-100% 1=100% in nodes. So for a blur ammount of 10% you would put in 0.1 into a node...

If you want to add a special kind of shader (such as anisotropic reflections, instead of regular reflections) you just add like-for-like shaders in the red-dots. Now there is a weird thing with LW in that specular and diffuse shaders completelly replace spec and diff surfacing. However, reflection shading and refraction shading only affect how light is bent, not the ammount of reflection/refraction, so you still need to add something to the green channels above...

The only exception to all of that is the materials slot (the cyan dot at the bottom) which will override everything.....

Except in all cases the bump/normal maps will still continue to function even with materials. It's odd but that's how it works :D

Also for simple metalics, use a Fresnel node with a metalic value (I have 2.9 in there, and the higher you make it, up to 100, the more reflective it will get) and then simply take the inverse (maths inverse) and feed that into diffuse, so it's properly energy conserving (diffuse+reflection=100%). Incident gradiets aren't as realistic as Fresnel, but they can be visually appealing, or 'realistic' isn't working for you :D

DrStrik9
05-29-2009, 07:09 PM
Ok.. Pretty much all of the options for the regular surfaces are recreated as node inputs:

However unless you plug a node into them, the old inputs work just fine. I.e. if you go to the advanced/environment surface properties and add reflection blur ammount, then it will work fine...

If you input a constant value node into the same input it will have the same effect. EXCEPT that with nodes they go from 0-1 - where Lightwave would go from 0-100% 1=100% in nodes. So for a blur ammount of 10% you would put in 0.1 into a node...

If you want to add a special kind of shader (such as anisotropic reflections, instead of regular reflections) you just add like-for-like shaders in the red-dots. Now there is a weird thing with LW in that specular and diffuse shaders completelly replace spec and diff surfacing. However, reflection shading and refraction shading only affect how light is bent, not the ammount of reflection/refraction, so you still need to add something to the green channels above...

The only exception to all of that is the materials slot (the cyan dot at the bottom) which will override everything.....

Except in all cases the bump/normal maps will still continue to function even with materials. It's odd but that's how it works :D

Also for simple metalics, use a Fresnel node with a metalic value (I have 2.9 in there, and the higher you make it, up to 100, the more reflective it will get) and then simply take the inverse (maths inverse) and feed that into diffuse, so it's properly energy conserving (diffuse+reflection=100%). Incident gradiets aren't as realistic as Fresnel, but they can be visually appealing, or 'realistic' isn't working for you :D

Excellent nodal texturing tut right there! :-) Thanks!

I am experiencing a strange phenomenon, however, with Fresnel. I tried to set mine up exactly like your example, but I get a SHARP halo (no smooth vignette at all) from the Fresnel node, no matter where I set it between 0 and 1 ...

Yours didn't look anything like this.

Bug? Something obvious I missed?

Thanks,
Michael

Kirdian
05-29-2009, 08:49 PM
I am experiencing a strange phenomenon, however, with Fresnel. I tried to set mine up exactly like your example, but I get a SHARP halo (no smooth vignette at all) from the Fresnel node, no matter where I set it between 0 and 1 ...

That's because Refraction Index from fresnel node can take values only between 1.0-100.0, not 0.0-1.0

DrStrik9
05-29-2009, 10:00 PM
That's because Refraction Index from fresnel node can take values only between 1.0-100.0, not 0.0-1.0

Thanks, much better.

Tobian
05-30-2009, 12:26 PM
Haha sorry yes, in the case of Fresnel, it inputs a value which correlates to IOR - which comes in 1-100 - if you'd put in 2.9 as I said it would have looked right hehe :)

and, yes, I should have mentioned that Fresnel uses IOR data. If you look up IOR data you will find metals in there, and you will think 'but metals aren't transparent?' and that's why - so you can feed the number into Fresnel number to get the correct falloff of diffuse to specular reflection values.

What I should have said is that where the value would normally be 0-100 it should be 0-1 - of course lots of type of data needs higher numbers than that, but that's not usually colour (unless you want super-bright hdr colours!) and Fresnel values go 1-100.