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Softer Shadows/ Diffuse Light?

DekeDeke Posts: 1,635
in New Users

Is there a way to soften shadows. I'm using Daz 4.9 and rendering in Iray using just the scene only. I have a distant light that I can control well...save for shadows. I wish there was a "diffuse" button to soften the light and also the shadows.  

Comments

  • SixDsSixDs Posts: 2,384

    That sort of thing is something that you find with biased render engines such as 3Delight. The whole point of render engines like Iray is to emulate realworld lighting. In the real world, bright lighting produces sharp shadows. If you wish to soften the shadows, you are on the right track with diffuse light - light that comes from multiple directions rather than a single source, such as one would find on an overcast day. I'm not an expert in Iray lighting, but I would guess that a similar effect could be created by using multiple, identical light sources arranged around the area of interest, which should dampen the effect of shadows. You would need to do some experimentation to create the effect you desire. Alternatively, you could try using an HDRI for lighting, using an image of an overcast sky.

  • mjc1016mjc1016 Posts: 15,001

    Or create a simple 'area' light...use a plain primitive, apply the emissive shader to it and scale up to several meters/yards in size.  Move it above the scene and adjust the levels (strength/power)...

  • DekeDeke Posts: 1,635

    Both great solutions....but wouldn't it be so much easier if Daz just included a "diffuse" slider on a light source?  Or a "Soft Shadows" sllider?  Maybe an idea for their next update.

  • ToborTobor Posts: 2,300
    Deke said:

    Both great solutions....but wouldn't it be so much easier if Daz just included a "diffuse" slider on a light source?  Or a "Soft Shadows" sllider?  Maybe an idea for their next update.

    Iray doesn't and won't have this because the quality of light comes from the type of light it is. You can't have a physically-based renderer if you create biased cheats. The realism that Iray imparts is specifically because it tries to base its rendering on real-world physics.

    There are two easy ways to create diffuse light. mjc1016 has already told you one -- it works because emissive objects, by default, emit diffuse light. For a plane this light spreads out 180 degrees from the surface. Make the plane large and bright enough, and it'll soak your scene with virtually shadowless light. To increase efficiency the geometry should have the lowest number divisions possible, and should emit light on one side only.

    The second easy method is to create a 2000 by 1000 medium gray JPG in a graphics program, then select that image for your Environment map. Adjust the intensity of the map to control lighting output. This will produce 100% global, monidirectional, flat, boring lighting to the entire scene. Do remember, however, that light from Iray's environment dome cannot penetrate walls and ceilings. That's how it works in real-life, and that's how it works in Iray.

  • DekeDeke Posts: 1,635

    I love Iray because it is real world physics based.  But in a real world, I can put a diffusion filter on a light. Could be a litle metal screen or could be a piece of diffusion filter clipped to the barn doors of the light. That's real world. So why not have a similar function for Iray. Why go through the added hassle of creating a plane and then assigning an emissive Iray material and then etc etc. The whole idea of computer programs is to make things easier....not more complicated.

  • dawnbladedawnblade Posts: 1,723
    Another way to soften shadows is to use spotlights and change their light geometry from point to rectangle, then increase height and width between 50 and 100.
  • mjc1016mjc1016 Posts: 15,001
    edited August 2017
    Deke said:

    I love Iray because it is real world physics based.  But in a real world, I can put a diffusion filter on a light. Could be a litle metal screen or could be a piece of diffusion filter clipped to the barn doors of the light. That's real world. So why not have a similar function for Iray. Why go through the added hassle of creating a plane and then assigning an emissive Iray material and then etc etc. The whole idea of computer programs is to make things easier....not more complicated.

    That's essentially what you are creating with using an emissive plane...a large diffusion filter.

    Post edited by mjc1016 on
  • ToborTobor Posts: 2,300
    Deke said:

    I love Iray because it is real world physics based.  But in a real world, I can put a diffusion filter on a light. Could be a litle metal screen or could be a piece of diffusion filter clipped to the barn doors of the light. That's real world. So why not have a similar function for Iray. Why go through the added hassle of creating a plane and then assigning an emissive Iray material and then etc etc. The whole idea of computer programs is to make things easier....not more complicated.

    You appear to want the quality of a physically-based Iray with the flexibility of made-up biased settings of 3Delight. These functions don't mix; you get one or the other. (You *can* get very realistic images out of 3Delight, but expect to spend a lot of time doing it. Renderman experts get a ton of money for their expertise when they devise shaders and lighting for Pixar and Dreamworks.)

    As a computer program, Iray (and similar renders like it) has made things MUCH easier compared to years past. The bar keeps rising as the capabilities increase. This is art with unlimited potential, and making use of that potential takes work. I can't imagine any of the old masters complaining how mixing their own paints from raw materials was so hard. It's part of the process of being creative. It's why their work hangs in museums.

    You can easily place a geometry in front of a light source to diffuse it. Make it partially transparent and give it a texture. Color it if you'd like. But don't expect the epitome of efficiency. Just because you can do it doesn't mean you should.

  • DekeDeke Posts: 1,635

    "Another way to soften shadows is to use spotlights and change their light geometry from point to rectangle, then increase height and width between 50 and 100."

    Great tip. never tried that before. 

  • AbnerKAbnerK Posts: 718
    dawnblade said:
    Another way to soften shadows is to use spotlights and change their light geometry from point to rectangle, then increase height and width between 50 and 100.

    Thanks this worked, brilliantly. Pardon the pun. :-D

  • SaldazSaldaz Posts: 168
    Deke said:

    I love Iray because it is real world physics based.  But in a real world, I can put a diffusion filter on a light. Could be a litle metal screen or could be a piece of diffusion filter clipped to the barn doors of the light. That's real world. So why not have a similar function for Iray. Why go through the added hassle of creating a plane and then assigning an emissive Iray material and then etc etc. The whole idea of computer programs is to make things easier....not more complicated.

    Nope, thats not how it works in real life. Increasing the relative size of the lightsource makes it softer (like large diffusion material in front of the light).

    If I want soft light like my 36 x 48 inch softbox in my real world studio I make spotlight in Iray and make it 36 x 48 inches.

    Iray is not super accurate but the principle is the same, large lightsource up close = soft light.

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