Create random textures over instances

[Yugs]

Hi,

Would it be possible to have this scripted graph working with an image texture input instead of a string value ?

That way one could, for instance, link an image node with UV transform information directly to the script. I tried to do it but I don't know the first thing about LUA. I just managed to change the string input to a texture one, but all I get is a blank material.

Thanks for this anyway, it comes very handy!

Cheers,

Yugs

[smicha]

Could you please help and make this script working under V4?

[roeland]

As far as I can see the script still works under version 4.

Would it be possible to have this scripted graph working with an image texture input instead of a string value ?

It's possible to create a similar script with texture inputs, how exactly depends on what exactly you want to achieve. Do you want one image texture input with a bunch of random additional transforms applied to it?

--
Roeland

[whersmy]

It's possible to create a similar script with texture inputs, how exactly depends on what exactly you want to achieve. Do you want one image texture input with a bunch of random additional transforms applied to it?

Would be very welcome.

Would it be possible to create an Amount and Scale input for the scatter node? I would like to reproduce a texture like this on a big surface

Actually OSL should be able to simulate this I think

[roeland]

Yes, this can be done using an OSL texture: You can start from the laminate example here: viewtopic.php?p=326508#p326508

Set the plankAspect to 1.0 for square tiles.

However, this shader will generate a random offset for every row of tiles. To get a regular pattern like in your picture find and replace the lines

Code: Select all

    // random offset for each row
    float x = p[0] + noise("cell", y, 0);

with

Code: Select all

    // alternate offset for each row
    float x = p[0] + 0.5 * ((int) y & 1);

[whersmy]

Getting there! Is it possible to add a random rotation for the square planks/tiles? In practice you would only need 4 options, each 90 degrees turned. In order to get the right irregularity for now I solved it roughness.

[smicha]

Share the scene please - great job.

[whersmy]

Here we go. Usable for buildings as well if displacement is not necessary.

[roeland]

Yes. The script as it is contains code to randomly rotate the texture by 180°:

Code: Select all

    int flip = (rnd - floor(rnd)) < .5;
    // make UV mapping per cell and evaluate the right texture
    float plU = x - floor(x);
    float plV = y - floor(y);
    if (flip)
    {
        plU = 1 - plU;
        plV = 1 - plV;
    }

We can extend this code: for instance this randomly picks any of the 8 combinations of rotation (0°, 90°, 180°, 270°) and mirroring.

Code: Select all

    int flip = (int) ((rnd - floor(rnd)) * 8);
    // make UV mapping per cell and evaluate the right texture
    float plU = x - floor(x);
    float plV = y - floor(y);
    if (flip & 1)
    {
        // flip U
        plU = 1 - plU;
    }
    if (flip & 2)
    {
        // flip V
        plV = 1 - plV;
    }
    if (flip & 4)
    {
        // flip over diagonal
        float tmp = plU;
        plU = plV;
        plV = tmp;
    }

[Rik]

Hi Rowland
Can you tell us how we would use this in the plugins? I use max but have no idea about how to incorporate the code.
It look like it would be really useful.