Adding a Mosaic Tifo

//example 

writePpmUvFile("C:/test15.ppm", 15, 15);

 

// 15, 15 being the values of length and width you may change it to your will

 

// code

global proc writePpmUvFile(string $filePath, int $length, int $width)

{

    if ($length > 256 || $width > 256) { error("Too big!!"); return; }

 

    string $fileContent;

    

    // header

    $fileContent += "P3\n"; // magic word

    $fileContent += ($length + " " + $width + "\n"); // length / height

    $fileContent += "255\n"; // max value

    

    // content

    int $colorIndex=0;

    for ($iL=$length-1; $iL>=0; $iL--)

    {

        for ($iW=0; $iW<$width; $iW++)

        {

            int $r = $iW;

            int $g = $iL;

            int $b = 0;

            $fileContent += ($r + " " + $g + " " + $b + "  ");

            $colorIndex++;

        }

        $fileContent += "\n";

    }

    

    // write file content

    $fileId = `fopen $filePath "w"`;  

    fprint $fileId ($fileContent);   

    fclose $fileId ; 

};

3. Once this .ppm texture is created , convert it in png for example into your favorite image editor.

4. Load the texture in your scene by selecting your placement geometry and creating a Paint Trigger Zone .

 

5. Place the crowd by selecting the faces and using the Population Tool  option "Create particles on selected component" .

 

6. To store the Id of your particles to offset the picture in your signboards create 2 ppAttributes in the crowd particles shape and name it "offsetYPP" and "offsetXPP".

 

7. In your shader scene create a shader for the signboards, using the maya 2D file texture connected to the shader color attribute. Be sure to map this shader to your Golaem character by going in the Character Maker geometry tab and clicking the reset shader button (save your gcha). 

Notice: the placement of the texture depends on the UVs of your signboard, check the UVs and adjust the placement with the Place2d texture's coverage and Offset.

 

8. Add two getUserdata shaders and link them to the placement2dnode U & V offsets (if using V-Ray do not forget that it is the outalpha that you need to link to the placement2dnode). This will enable you to control the U & V offset of the texture applied to a particular tile with the offsetX and offsetY ppAttributes. See this tutorial to learn how to feed the getUserData shader with ppAttributes values.

9. Go to the Geometry Tab in the Character Maker, find the shader assigned to your signboard and add two float Shader attributes to allow it to perform the uv offset: offsetX and offsetY. You can also use the Reset Shaders button  after selecting the signboard Mesh Asset node. This will add the Shader Attribute nodes automatically. Tick the box to use the ppAttribute of your particles offsetXPP and offsetYPP.

10. Go into your Behavior editor and drag and drop an Attribute Behavior  into the Behavior Graph of your entities.

11. Edit its stop trigger for your entities to path through it and read the other behaviors we may add behind it.

12. Inside the attributes of this behavior add some new expression to get the particles offset in X values.

We are working on a texture of 255 values in red [r] yet we want to divide it to the number of rows of our entity group (15 in this case)

And some expressions to get the particles offset in Y values.