adding 1d texture example for grid

[thomwolf]

Adding a bit better support for textures and colors.

Typical example to assign a texture as a function of the height of a structured map:

proc_grid = sm.ProcgenGrid(specific_map=specific_map)

# Let's color our grid by height.
# We assign a simple 1D texture to the object and assing mesh texture coordinates from the height of each points of the mesh.
proc_grid.material.base_color_texture = sm.TEXTURE_1D_CMAP  # Set a simple 1D color map texture
height = proc_grid.mesh.points[:, 1, None]  # We get the height coordinates of the mesh points ( theY axis)
texture_coord = np.concatenate(
    [height, np.zeros_like(height)], axis=1
)  # Make texture coordinates (UV) by adding a zeros axis
proc_grid.mesh.active_t_coords = texture_coord  # Assign as point to texture mapping

scene += proc_grid

[aliciafmachado]

Changes look fine, but I'm getting some strange results in procgen_grid.py:

And it doesn't seem to be working with Unity.

[natolambert]

Anything I can do to support this? I agree that textures will be fun. Let me poke around, as I was looking at a related script for #144

[natolambert]

This is the color scale we should be getting:

COLORS_NO_GRAYSCALE = {
    "BLUE": BLUE,
    "CYAN": CYAN,
    "GREEN": GREEN,
    "MAGENTA": MAGENTA,
    "OLIVE": OLIVE,
    "PURPLE": PURPLE,
    "RED": RED,
    "TEAL": TEAL,
    "YELLOW": YELLOW,
}

Weird for it to jump from red to green (I was looking to see if one of the colors was mis-defined as blue in between red and green), but also the spacing is off.

For reference, if you take the x-axis, a similar pattern emerges (I think the steep part is hard to see because shadow)

.

[natolambert]

I'm really going deep on this, a good way to learn. Here's "greyscale" Our colors are definitely not alright

.

[natolambert]

@dylanebert mentioned it may be a gltf encoding issue, so I tried to export the scene and was given a cryptic warning and no output.

 2022-08-03 15:29:38.973 ( 128.648s) [           13DD4]       vtkPNGWriter.cxx:213   WARN| vtkPNGWriter (0x15eceb300): PNGWriter only supports unsigned char and unsigned short inputs

This may be a better thing for someone other than me to fix then, I'm a gltf noob.

[thomwolf]

Let me take a quick look to see if I can help!

[thomwolf]

Ok it's working fine now for structuredgrid.

For StructuredGrid and their child classes (procedural generation) I've added a add_texture_cmap_along_axis

The example procgen_grid.py shows three ways to add a cmap texture using this add_texture_cmap_along_axis method.

[aliciafmachado]

Not working on my side: https://pastebin.com/zq5mAQq6
It seems like it has something to do with the show function in the pyvista engine.