Materials & Shaders

[Lyonz]

Hi all im wondering if anyone knows how to create a 2 sided shader ?

Thanks

[anim]

there is Two Sided VOP in surface SHOP

[old school]

As a side note, since the 2 sided shader doesn't do a front face operation, be wary of your primitive normal direction as that is what determines what is out and what is in.

[Lyonz]

As a side note, since the 2 sided shader doesn't do a front face operation, be wary of your primitive normal direction as that is what determines what is out and what is in.

What is this 2 sided VOP called ?

Also is there a shader forum like what V Ray has ?

[anim]

again it's called : Two Sided

[Lyonz]

Wondering if anyone has tried to use the car paint shader on the houdini website under exchange?

As i have tried doing a File - Install digital asset library, putting it into the otl folder in the c drive but its not showing up ???? i am wondering if its named something else under the tab menu ??

Thanks

[old school]

It should show up in /shop. If you hit tab and then look in the Digital Assets folder it should be there.

It won't show up in the Material Palette because it isn't wrapped up in to a material folder. You can do that if you want and then it will show up in the Material Palette

[Lyonz]

Thanks for replying,

Yes i can use the car paint shader now but have a new problem. I want to give my dodge viper red paint and white racing stripes but i am unable to do this by using a group sop followed by a material node as my mesh flows into the curves and i need straight lines.

Is there a way to project straight lines onto the car and tell it to use the white paint shader ? or a way of layering this up as i know how to do this with texture maps in the layered surface sop but it doesnt allow you to use other shaders.

Thanks in advance

[kelvincai]

You could assign groups on the geometry via Group SOP and assign different shaders via a Material SOP. If the geometry doesn't give you straight lines, you could assign UVs and use texture maps. If the shader you using doesn't take textures, you have to add the textures function by yourself in VEX/VOP or use other shaders which take textures. These are about what I can think of for now.

[Lyonz]

You could assign groups on the geometry via Group SOP and assign different shaders via a Material SOP. If the geometry doesn't give you straight lines, you could assign UVs and use texture maps. If the shader you using doesn't take textures, you have to add the textures function by yourself in VEX/VOP or use other shaders which take textures. These are about what I can think of for now.

Like i said i carnt use group and material nodes because of the curves in the geometry and dont want to change the geometry.

Carnt use uvs with different layers as i want to use the car paint shader not textures.

The car paint shader doesnt have a texture slot.

And carnt add a texture parameter because the car paint shader is locked.

kinda stuck need a solution...

Thanks in advance

[anim]

you can either, right click the shader choose Type Properties... and edit code so it allows you to use textures

the code is clearly generated from VOPs and not hand written so after investigation you can find that in example fresnel_cs4.hipnc file from exchange there is source VOP shader

it's called car_paint11, just Right-Click/Edit VOP Network and you can add texture support visually in VOPs

[kelvincai]

Like i said i carnt use group and material nodes because of the curves in the geometry and dont want to change the geometry.

Carnt use uvs with different layers as i want to use the car paint shader not textures.

The car paint shader doesnt have a texture slot.

And carnt add a texture parameter because the car paint shader is locked.

kinda stuck need a solution...

Thanks in advance

Study the shader(s) you have at hand, via its VOP networks or VEX codes. Then add the functionality you need, if the shader(s) doesn't provide it. And, it is not so hard to write a new shader from scratch too. It is so much easier to write VEX/RSL shaders compared to mental ray or vray shaders.

[Lyonz]

you can either, right click the shader choose Type Properties... and edit code so it allows you to use textures

the code is clearly generated from VOPs and not hand written so after investigation you can find that in example fresnel_cs4.hipnc file from exchange there is source VOP shader

it's called car_paint11, just Right-Click/Edit VOP Network and you can add texture support visually in VOPs

I have tried looking for this but can not find in on the exchange wondering if it has moved ?

[anim]

http://www.sidefx.com/exchange/download.php?fileid=352&type=HIP

[Lyonz]

Is there anyway to mix two shaders like a blend mode ? As i am trying to create condensation

Lyonz

Edited June 11, 2010 by Lyonz

[Lyonz]

Hi all,

Im wondering if someone could explain to me the difference between a complement node, negate and invert at vex level ?

Thanks

[anim]

complement = 1-x

negate = -x

invert = 1/x

[Lyonz]

complement = 1-x

negate = -x

invert = 1/x

So basically

complement = 1- itself, take away 1

negate = make it neutral - itself = 0

invert = divide 1 by x