Gobos in Superfly?

  • @bagginsbill said in Gobos in Superfly?:

    @amylbone said in Gobos in Superfly?:

    Has anybody had any luck using gobos in Superfly?

    Yes. Well, not luck, just physics and/or geometry, but yes.

    Before I bother to demonstrate, there are two definitions of gobo and I would need to know which one you care about.

    • a dark plate or screen used to shield a lens from light.


    • a partial screen used in front of a spotlight to project a shape.

    Very much the latter. I'm looking to do some Noir style piccies with shadows of jail windows, blinds and what have you.

  • @anomalaus said in Gobos in Superfly?:

    @amylbone I had to look this word up. Since you're obviously not asking about Japanese root vegetables, you must mean the other(s).

    Though most would speak with more authority, it's my understanding that the reason for having a gobo would be to reduce lens flare, I'm not sure what utility that would be at all in Poser. I recall seeing posts where people have gone to great lengths to actually simulate lens flare, since I was not aware of it being an option in any of Poser's render engines. I do note that the cameras have parameters allowing for the control of Bokeh effects (Aperture Blades and Aperture Blades Rotation), but that translates as out-of-focus, pinhole light shapes, not multiple element lens internal refractive effects.

    Unless,... the gobo you're referring to is a silhouette mask for a light emitter to shape the boundaries of a beam of light from a light or other emitter? Area lights always cast soft shadows, so a gobo? would be less effective than with a spot light.

    These aren't the Gobos you're looking for... ...it is silhouettes I'm looking for. I assumed area lights would be perfect because you can control the shape but you have explained at least part of my failure.

  • @amylbone
    Does the FireFly method of putting an image or a procedural in a spotlight not work in SuperFly?
    In FF you turn a spotlight into a projector that way. I never tried in SF.

  • Poser Ambassadors

    When using a physical prop as gobo (which casts a shaped shadow), I'm almost sure your problem has to do with the size of the light.

    This is no good, because the scale of the light source (a spot light in this case) permits seeing light at a lot of different angles from the ground points.


  • Poser Ambassadors

    In SuperFly, point lights are not points, they are spheres. Spot lights are not points, they are disks. Area lights are rectangles. All of these have an actual physical size, which causes them to produce shadows in proportion to the angle subtended by the light source from the point of view of the target object. The size of these is easily controlled with the "Scale" parameter. You want them to be small like a coin, not big like an umbrella.

    Here I have scale=10%.


  • Poser Ambassadors

    This is my setup for the gobo which is just a Poser one-sided square interposed between the light source and my subjects.

    I'm using transparency to control where the light can go through. This works for FireFly as well.

    Note that the term "transparency" is a long-standing misnomer. Properly speaking, this is an opacity mask, not a transparency mask. It's opposite, because where the mask is 1 (maximum) the prop is opaque, and where the mask is 0 (minimum) the prop is not opaque. Therefore the value is directly controlling opacity.


  • Poser Ambassadors

    Using a Cycles-style shader, we can flip that on its head and the same mask is now actually a transparency mask.

    The shadow is in the shape of the lion, not the shape of the gobo square.


  • Poser Ambassadors

    More gobo trickery is to combine the mask with a color image to project the colors in a specific boundary.


    Other variations are possible.

  • @bagginsbill "dem bricks ain't straight! Dey's lion!" ;-)

  • @bagginsbill Fantastic, thank you! As ever you have made the baffling simple or at least understandable. You have shed light on the reason for my lack of success I would never have thought of scaling the lights down. Although that does make perfect sense as that is pretty much the definition of focus. Well technically the definition of Focus is the Hearth, but only in a literal sense in the original latin. Oh dear, I'm digressing again. Anyway thanks for the help.