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Textures: Xonotic Items as decals - Printable Version

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Textures: Xonotic Items as decals - Julius - 05-13-2020

Julius Xon-Items Decal Set

       File: j-xon_items_v1.0.zip
License: GPL v2
 Author: Xonotic & Julius

This is a small set comprised of 48 decal textures made from some SVG source files taken from Xonotic.




The shader for every texture is like this:

    qer_editorImage textures/j-xon/items/i_armor.tga
    qer_alphaFunc gequal 0.5


    //q3map_vertexScale 0.75

    surfaceparm trans
    surfaceparm nonsolid
    surfaceparm pointlight

        map textures/j-xon/items/i_armor.tga
        rgbGen vertex
        // (source * alpha) + (dest * (1 - alpha))  <= Alpha blend
        blendFunc blend

Some words related to the shaders:

  - Lighting method: VERTEX-LIT

    “surfaceparm pointlight” and “rgbGen vertex” shader directives are used to set these textures to be
    vertex-lit so they are faster to render because no lightmaps are used. Keep in mind that no lightmaps
    means no shadows are cast on these surfaces.

  - Some explanations for other shader directives:

    polygonOffset                                  ;this avoids z-fight rendering the texture separated from the surface.

    noPicMip                                          ;this ignores the gl_picmip cvar (textures resolution).

    q3map_vertexScale N.N                ;this is a multiplier for the sampled light at vertices. Understand it as
                                                                a way to increase or decrease the amount of light hitting the surface.

    surfaceparm trans                          ;this does not set transparency. It sets the surface to no VIS-blocking,
                                                                no Shadow casting (*1) & no Bounced light (*2).

      (*1): It cast shadows if accompanied with "surfaceparm alphashadow". The alpha-channel image will be
               the shadowcaster.

      (*2): I do not understand why Bounced-light is disabled here. It doesn't make sense to me. Note that I'm
               not a coder so I can't read q3map2 sources to know what this directive does exactly.

    surfaceparm nonsolid                     ;this disables the collisions with players and projectiles
    surfaceparm pointlight                    ;this forces vertex lighting for this surface

    blendFunc blend                              ;alpha blend

    "blendFunc blend" is the equation that tells the game engine how it should mix the different graphical

      - equation:    (source * alpha) + (dest * (1 - alpha))
      - explicit:        blendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA
      - shorthand:  blendFunc blend

      "souce" represents the texture itself.
      "alpha" is the black & white mask contained in the alpha-channel.
      “dest” is the content of the frame-buffer (the background image with which to blend the texture).

      More info from the shader manual: blendFunc

Ok, that's all for now. Any comment will be really appreciated. Wink


RE: Textures: Xonotic Items as decals - Garux - 05-14-2020

Quality stuff, looks usable even out of Xonaughtic lore.