Color To Float and Float To Color Utility.

[fantome]

Hi Guys,

Maybe i have miss a strategic node, but i can't separate RGB output of a node and access each channel individually to remap them.

So having a
- Color to Float
- Float to Color
Tool Utility node would be nice.

Cheers
Emmanuel

[juanjgon]

Yes, I agree that more math tools nodes are needed. I suppose that with the future OSL support, add these nodes should be easy.

Some workarounds are possible now, like for example use the texture multiply and mix nodes to extract components and later mix them again, but anyway could be better have real math nodes.

Thanks,
-Juanjo

[fantome]

Thanks for your answer Juanjo.

So basically with the support of OSL we will get :
- native support of geometry attribute
- more math tools
That will make me a happy camper !

The release of 3.1 is still plan for 2016 ? Or are there any delay ?

Cheers
E

[juanjgon]

I am not sure yet, sorry, but I suppose that we should get some news about new features soon, now that the 3.0 version seems stable enough.

Thanks,
-Juanjo

[fantome]

Thanks again for your answer.

[fantome]

I would like to know if someone has find a good way to have :
- RGB to Float
- Float to Color
With the OSL tools or an other tricks ?

I have play with OSL texture a little but it look that you must output a color.

Code: Select all

shader rgbToFloat(
    color A = 0,
    output color B = 0)
{
    B = luminance(A);
}

This one compile

Code: Select all

shader rgbToFloat(
    color A = 0,
    output float B = 0)
{
    B = luminance(A);
}

This one return me an error

I would like to plug a falloff in to the power parameter of a texture emission node, but i can't get it working.
When i plug it in the slot it does nothing. It looks that there are no auto conversion like in mantra ( luminance(RGB) ).
Octane simply doesn't understand my RGB input.

For the moment i plug it in the texture slot , but i would love to handle color and power with the respective correct slots.

If you have any idea that would be great !

[juanjgon]

The Octane OSL nodes inside Houdini implemented as VOP nodes work is not finished yet, so perhaps this is why they don't work on your end. Now that the Houdini 17 plugin and Octane 4.00 builds have been released, finish all the OSL stuff in this plugin is a top priority.

Thanks,
-Juanjo

[fantome]

Thanks a lot for your very fast answer Juanjo !

So for being sure i have not omit anything, cause i'm quite new to octane.
At the moment you can't convert an RGB value to a Float Value, and this look to be a octane standalone restriction not a houdini plugin problem ?

The only thing i will be able to plug into the power slot of a texture emission node inside houdini is a float value node ?

Thanks again for your time.
Cheers
E

[juanjgon]

Yes, I think that Octane doesn't have these kinds of native nodes even in the Standalone, but someone could correct me if I'm wrong ...

Thanks,
-Juanjo

[roeland]

That’s correct, you can’t send a color output to a float input pin, Octane expects a constant value for these pins. So probably you have to use a multiply node with your color and power textures.

There are alternatives for some use cases. An image texture node has a power input which accepts a texture. To create things like spotlights and projectors the usual way is to connect some kind of falloff texture to the distribution input of the emission node.