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Thread: Specular Highlights

  1. #1
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    Specular Highlights

    Hi!

    Is it possible to get reflection of sun on material without using specular input and glossiness, just from reflection and reflection blurring input?

    Thanks!

  2. #2
    Space Monkey 3DGFXStudios's Avatar
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    Yes! If your sun is a 3D model or the newly added Ngon light type.

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    That sucks
    So on every materials we must use specular...
    Thanks

  4. #4
    Of course, just don't use specular or glossy, have something in the scene that represents the sun and you will get sun reflected in your surfaces. It cold be a HDRI or an actual sun object or what ever you decide it should be, it won't be your actual light, that won't show up in reflections (that shows up in specular, but you won't be using that), so you have to put something in the scene that will be the sun and be reflected.

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    Dp sunsky does not have that kind of option, right?

  6. #6
    Just in case, DP Sunsky is reflected on surfaces.



    Gerardo

  7. #7
    RETROGRADER prometheus's Avatar
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    Quote Originally Posted by medzo View Post
    Dp sunsky does not have that kind of option, right?
    The Dp sunsky reflects in reflective surfaces,you can increase reflection over 100 if you want to get more like specular values, but it reflects even without specular.
    throw in a sphere, make it 100-110 reflective, add sunsky, swith sun to sk_sunlight, and use manual mode to control it with standard rotation values.

    sunsky has no options for clouds or anything like that, youīd have to use hypervoxels, or a combination with sunsky and cloudbackdrop images, in textured environent for example.

    Michael

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    Hi

    The effect using just fresnel with inverted diffuse is really hardly noticeable, meanwhile with delta material - reflection of the sun is much clearer. Click image for larger version. 

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  9. #9
    RETROGRADER prometheus's Avatar
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    Quote Originally Posted by medzo View Post
    Hi

    The effect using just fresnel with inverted diffuse is really hardly noticeable, meanwhile with delta material - reflection of the sun is much clearer. Click image for larger version. 

Name:	fresnel node.jpg 
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ID:	119226Click image for larger version. 

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    what type of effect or surface reflection are you after? delta is a somewhat translucent material. for more metal look, use conductor, check reflection blurring and control it with roughness.

    you also got the brdf shader in the shaders tab to give you anisotropic specular shading, also available in nodes, but you got to have specular value on for standard brdf shader to work.

    Michael

  10. #10
    Of course it's possible, you just need to ramp up the power of the thing you're trying to reflect. In nature, the sun is ridiculously bright, in lightwave terms tens of thousands of %, which if you handle it as reflection blur, will result in splotchy blotchy sparkly sprinkles.. This is where a mix of reflection and spec is the best combination. personally I boost the specular produced by Delta, using DB&W's material tweaker node. I go into my workflow here, http://www.andrewcomb.com/pluto_stat...group-webinar/ , and you can download some sample materials, which will work correctly using either lights/spec or using HDR environments.

    As a note, Delta has 'specular' as well as 'reflection' in a combined shader, but the specular power is usually way too weak, hence i boost it, after applying the Fresnel response. DP Sunsky is not really any different to how normal lights behave: You both need to boost, massively, the intensity of the sun-disk in the shader, and boost the specular in your materials.

  11. #11
    RETROGRADER prometheus's Avatar
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    Quote Originally Posted by Tobian View Post
    Of course it's possible, you just need to ramp up the power of the thing you're trying to reflect. In nature, the sun is ridiculously bright, in lightwave terms tens of thousands of %, which if you handle it as reflection blur, will result in splotchy blotchy sparkly sprinkles.. This is where a mix of reflection and spec is the best combination. personally I boost the specular produced by Delta, using DB&W's material tweaker node. I go into my workflow here, http://www.andrewcomb.com/pluto_stat...group-webinar/ , and you can download some sample materials, which will work correctly using either lights/spec or using HDR environments.

    As a note, Delta has 'specular' as well as 'reflection' in a combined shader, but the specular power is usually way too weak, hence i boost it, after applying the Fresnel response. DP Sunsky is not really any different to how normal lights behave: You both need to boost, massively, the intensity of the sun-disk in the shader, and boost the specular in your materials.
    I donīt think the intensity of the sun_disk in the dp sunsky reacts at all unfortunatly, not from what I have seen, or maybe it just donīt work with vpr and only final render, lightwave chrashed when testing right now.

    Michael

  12. #12
    Quote Originally Posted by medzo View Post
    Hi

    The effect using just fresnel with inverted diffuse is really hardly noticeable, meanwhile with delta material - reflection of the sun is much clearer.
    Reason why you are getting a much clearer sun reflection with Delta material (or other materials) is because you have "Affect Specular" option enabled in your sun light, and materials are taking specular highlights into account, while when using only reflection parameter, specular highlights are ignored.

    In order to work with more correct diffuse and reflections values, we need to disable the Inv. Exp. Exposure parameter. D50 adapted color system versions can be used for a correct color reproduction when previewing directly in computer monitors. Use later DP Linear Tonemap (no Exposed Render) in DP Node Image Filter to appropriately expose the render.


    (Reflection&Diffuse-only test)



    Gerardo

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    Hi

    I am reviving this thread because the question is related to the topic.

    When using specularity (highlights), for physical correct output, do I need to multiply the input with fresnel?

    I am attaching two examples for my leaves material, which one is 'more' correct when it comes to specular input?

    Click image for larger version. 

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    Click image for larger version. 

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  14. #14
    Specular should be the exact same value as reflection, a simple low-value fresnel, but then multiplied by an amount to boost it to realistic values: between 20 and 50. This may result in unwanted noise issues, but it's closer to reality.

    As a note, translucency and diffuse should be equal to the remainder of fresnel, as they are both forms of transmission, albeit faking thin sss for this :-)

  15. #15
    Quote Originally Posted by gerardstrada View Post
    Reason why you are getting a much clearer sun reflection with Delta material (or other materials) is because you have "Affect Specular" option enabled in your sun light, and materials are taking specular highlights into account, while when using only reflection parameter, specular highlights are ignored.

    In order to work with more correct diffuse and reflections values, we need to disable the Inv. Exp. Exposure parameter. D50 adapted color system versions can be used for a correct color reproduction when previewing directly in computer monitors. Use later DP Linear Tonemap (no Exposed Render) in DP Node Image Filter to appropriately expose the render.


    (Reflection&Diffuse-only test)



    Gerardo

    I'm needing clarification, what is the "Inv. Exp. Exposure parameter" referred to here?

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