Carrara shader - fade to transparent?

tami_7956c1f21dtami_7956c1f21d Posts: 0
edited December 1969 in Carrara Discussion

Hello there,
I'm hoping someone can help me make a shader in Carrara that goes from opaque to transparent. I want to have several objects (these are simple cylinders) fade out. I assume the easiest way to do this is via a shader, but I don't know how to make it.

Your help is greatly appreciated! I'm not brand new to Carrara, but I don't often work with complex shaders.

Comments

  • DUDUDUDU Posts: 1,835
    edited December 1969

    It' easy, you have an alpha channel in your shader, at 0 % your shader is transparent...
    It' animable too.

  • tami_7956c1f21dtami_7956c1f21d Posts: 0
    edited December 1969

    Thanks. However I want the same object to be opaque on one end and transparent on the other. So I think I need something like a black to white gradient in one of the channels, to make the alpha mask, but I don't know where to put it.

  • DUDUDUDU Posts: 1,835
    edited March 2014

    Here a cylinder with a black and white picture in Chanel alpha…

    Doc3.jpg
    640 x 480 - 59K
    Traçés.jpg
    500 x 500 - 124K
    Post edited by DUDU on
  • jrm21jrm21 Posts: 122
    edited March 2014

    When I first read this, I thought you meant fade out over time. In that case, Dudu's suggestion will work great... you can have the alpha value change over time to fade the entire object out.

    You are looking for something else. There are different ways to do this. One way is to put a texture map in your shader's alpha channel. See the attached screenshot for one way to set up your shader. The texture map is a tif file made in photoshop. You can use tif or jpeg and create it in any graphics program.

    I set the object color to dark red just to show how the B&W of the alpha channel doesn't affect object color. This is just a simple gradient. You can customize the gradient to change visibility anyway you like. You can also use other built in items in lieu of a texture map to get various effects.

    sample.jpg
    1172 x 577 - 66K
    Post edited by jrm21 on
  • evilproducerevilproducer Posts: 8,789
    edited December 1969

    Thanks. However I want the same object to be opaque on one end and transparent on the other. So I think I need something like a black to white gradient in one of the channels, to make the alpha mask, but I don't know where to put it.

    Is the opaque end supposed to remain opaque throughout the animation? If so, then a mixer in the alpha channel may be the way to go. You would have your graduated shader as one source and you opaque shader as another, then use a slider in the mixer. The you could slide the slider over to reveal the graduated shader.

    Also, transparent can mean a couple things. Water is transparent and refractive, so is glass. Did you want something that goes just plain old invisible with no refraction? Or did you want it to look like it went clear, similar to glass?

  • tami_7956c1f21dtami_7956c1f21d Posts: 0
    edited December 1969

    Thanks so much everyone!

    I want the objects to have their faded edge -- remain faded--throughout the animation. jrm21's suggestion is exactly what I needed - black and white gradient as a texture map on the alpha channel.

    Problem solved! I really appreciate everyone's help on this.

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