3Delight Laboratory Thread: tips, questions, experiments

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  • wowiewowie Posts: 2,029
    edited August 2017

    Got SSS working. On the left is basic translucence, right is with just subsurface. On the second pic, the right one has subsurface plus translucence.

     

    Of course, no subsurface test is complete without a skin test.

    Rendered at 12x12 pixel samples, so took a bit of time (roughly 9 and half minutes with UE2 IDL at 8 samples) to render.

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    Post edited by wowie on
  • Mustakettu85Mustakettu85 Posts: 2,933
    wowie said:

    Something like this?

     

    https://www.nda.ac.uk/blog/translucent-concrete/

    A feature request? Sure, I can add a switch to control the resulting translucency shadows. I'm guessing you want a slider to control the intensity as well?

    That's an awesome example. Yes, exactly. A slider would be lovely, too!

  • RAMWolffRAMWolff Posts: 10,146

    WOW... can't wait for this to be available! 

  • Oso3DOso3D Posts: 14,889

    Remind me again, does UE2 play nice with AOA lights?

     

  • wowiewowie Posts: 2,029

    Remind me again, does UE2 play nice with AOA lights?

    Depends. The Adv Spot and Point lights works OK, though I just use them as basic lights without flagging.

    Using the Adv Ambient Occlusion light with UE is redundant since they both have ambient occlusion.

  • Oso3DOso3D Posts: 14,889

    I assume distant works, too?

    I don't generally do anything fancy with lights

  • wowiewowie Posts: 2,029

    I assume distant works, too?

    I don't generally do anything fancy with lights

    I didn't test it, but there shouldn't be any problems.

  • wowiewowie Posts: 2,029
    edited August 2017

    HOT DAMN!!! This just made my day. laugh

    The raytraced 3delight SSS indeed is a proper raytraced subsurface scattering solution. We can now have actual blocking geometry underneath the surface affecting the material. No need to fiddle with transmission or opacity. It just works.

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  • RAMWolffRAMWolff Posts: 10,146

    WOW Wowie!  That's cool!

  • Oso3DOso3D Posts: 14,889

    Other than SSS, what is the easiest/fastest way to get a little candling (ears, etc) on a figure?

    If I use translucency, do I need to reduce Opacity? Diffuse?

     

  • Oso3DOso3D Posts: 14,889

    Light leak with US and UE2... higher occlusion sampling or an issue with a shader setting?

  • RAMWolffRAMWolff Posts: 10,146

    So I have a new question.  I made a mask, black to keep things normalized on for the rest of the surface and the white to give me a fake light source to make a "jewel" glow.  What channel do I set that up in using the basic 3DL surfaces?  I'm using the Skin lighting model so I have a few more channels that using that opens up.  Thanks so much

  • Mustakettu85Mustakettu85 Posts: 2,933

    Other than SSS, what is the easiest/fastest way to get a little candling (ears, etc) on a figure?

    If I use translucency, do I need to reduce Opacity? Diffuse?

    Unless you're talking one specific "translucency" from pwSurface, "translucency" channels won't work for meshes with volume. They are "reverse diffuse": they pick up light from the "bad normal" side of a single-poly surface, like leaves, transmapped hair, dynamic clothing.

    If you reduce opacity, it will just look weird.

    The easiest way to fake "candling" (is it an "official" word? I'm curious because I'm not a native speaker) is putting diffuse textures into ambient as well and using a black ambient strength map with areas painted in grey shades where you want the fake SSS. You may or may not want to balance diffuse then. Artistic choice.

     

  • Mustakettu85Mustakettu85 Posts: 2,933
    RAMWolff said:

    So I have a new question.  I made a mask, black to keep things normalized on for the rest of the surface and the white to give me a fake light source to make a "jewel" glow.  What channel do I set that up in using the basic 3DL surfaces?  I'm using the Skin lighting model so I have a few more channels that using that opens up.  Thanks so much

    Same answer as for Tim above: ambient strength. Ambient colour is to adjust the, well, colour of the glow.

    Are you sure you want the "skin" mode on the material that includes a jewel? This mode disables reflection.

  • Mustakettu85Mustakettu85 Posts: 2,933

    Light leak with US and UE2... higher occlusion sampling or an issue with a shader setting?

    Could be anything, including a bad model. Hard to say unless you provide more context.

  • wowiewowie Posts: 2,029
    edited August 2017

    Other than SSS, what is the easiest/fastest way to get a little candling (ears, etc) on a figure?

    If I use translucency, do I need to reduce Opacity? Diffuse?

    Old school way, point light inside the model with very short falloff distance. You can use flagging or light categories too, I suppose. Translucency won't work since it's geared towards simple, infinitely thin polygons. One thing about SSS with the available shaders - backscatter is mostly influenced by direct lighting.

    Light leak with US and UE2... higher occlusion sampling or an issue with a shader setting?

    I'd say neither. Most of the time, it's improperly modelled props - walls with single facing normal, no thickness and lack of bevel where the planes meet. One workaround is to use an envelope on the backside to cover up intersecting parts (or the entire model). Technically you can use a geoshell for that, but that is highly dependent on the model.

    More or less, the same problem with glass surfaces. Can't have physically correct output with non physical models.

    The rest of the time, it's a too high shadow bias value. Use something like 0.01. UE2's default is 0.1 while DAZ default lights is 1.0.

    RAMWolff said:

    So I have a new question.  I made a mask, black to keep things normalized on for the rest of the surface and the white to give me a fake light source to make a "jewel" glow.  What channel do I set that up in using the basic 3DL surfaces?  I'm using the Skin lighting model so I have a few more channels that using that opens up.  Thanks so much

    Anyhting that glows is generally emissive so put the mask on ambient strength and set the strength to anything but zero. Also make sure the ambient color is bright enough and ambient is set to enabled. If you use UE2's IDL or bounceGI mode, it will actually cast light to the scene, depending on the total strength (strength multiplied by color) and UE2 max trace distance.

    Don't put the mask in the color slot, or worse, put it in the color slot AND strength slot. Make sure the black in the mask is zero.

    Post edited by wowie on
  • Oso3DOso3D Posts: 14,889

    Eh, guess I'll just not worry about it. If I REALLY need it I'll use actual SSS.

    Good to know about shadow bias.

     

  • RAMWolffRAMWolff Posts: 10,146

    Yea, figured it out earlier... I kinda figured it was ambient but wasn't sure how to do it up but then things started clicking and I was plenty happy with the results.  I like the skin mode as it makes the skin more rich looking for characters and since this is just a diffuse map and not an actual prop I can't have one channel set to one and all the others set to another as it would reveal uv seams. 

     

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  • Oso3DOso3D Posts: 14,889

    Ah, it looks like at least one problem was not upping path.

     

  • Oso3DOso3D Posts: 14,889
    edited August 2017

    Ok, I've figured out the problem. AoA distant light does _not_ play well with UE2; it causes a huge amount of light bleed in touching surfaces.

    Well, poo.

    At least it's easy to switch to a regular distant light.

    (I also suspect this is what was causing troubles I had with Marshian's Reflective Radiance)

    Post edited by Oso3D on
  • SaphirewildSaphirewild Posts: 6,648

    Ok, I've figured out the problem. AoA distant light does _not_ play well with UE2; it causes a huge amount of light bleed in touching surfaces.

    Well, poo.

    At least it's easy to switch to a regular distant light.

    (I also suspect this is what was causing troubles I had with Marshian's Reflective Radiance)

    I just bet it was the problem all along :)

  • Mustakettu85Mustakettu85 Posts: 2,933

    Ok, I've figured out the problem. AoA distant light does _not_ play well with UE2; it causes a huge amount of light bleed in touching surfaces.

    ...

    (I also suspect this is what was causing troubles I had with Marshian's Reflective Radiance)

    If you were using UE2 for IDL (which you didn't mention), then yes it's very likely.

    AoA's Spot and Distant trace shadows from the surface to the light (normally "delta" lights do it the other way), and the Distant uses some sort of an unconventional strategy for this. It threw 3Delight's built-in GI algorithm off as well.

  • wowiewowie Posts: 2,029
    edited August 2017

    Double side for non physically correct, infinitely thin plane is done. Previously it only works with diffuse, now it works with metals and glass. Roughly the same as the thin shadows / wall feature in other shaders.

    I'm thinking about allowing different/separate diffuse so you can have one color/texture on one side, and another on the other side. Obviously, not applicable for glass or metals.

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    Post edited by wowie on
  • Mustakettu85Mustakettu85 Posts: 2,933
    wowie said:
    I'm thinking about allowing different/separate diffuse so you can have one color/texture on one side, and another on the other side.

    That would be useful for many models out there.

  • Sven DullahSven Dullah Posts: 7,621

    Is there any way in 3DL to have a ceiling light reflect in a mirror and be cast on the floor, like using the caustic sampler in IRay? Any shader/product/light/whatever?

  • Sven DullahSven Dullah Posts: 7,621
    carrie58 said:

    Thanks carrie58! It went into my wishlist but I'm not sure it can give me the effect I want. Seems to me you're limited to using the props/lights included in the product to get a realistic look? I'll try to dig up the read me, maybe it'll give me some clues about how to use it.

  • Sven DullahSven Dullah Posts: 7,621

    http://docs.daz3d.com/lib/exe/fetch.php/public/read_me/index/18282/18282_easy-caustics.pdf

    Ok so I went through this and I don't think it can do what I want it to do, although probably usable in some random casesfrown. Any other suggestions for reflecting a ceiling light in a mirror to be cast on the floor? Appart from using IRay?

  • Takeo.KenseiTakeo.Kensei Posts: 1,303
    edited December 2017

    The only way to do caustics properly with 3DL is through photon mapping

    There is a video from DAZ somewhere on Youtube to set up a "Shader Light" as well as a Camera with photon mapper with the Shader Mixer

    To do what you want you also need some proper shaders but I don't think I've ever seen anybody writing these

    There may be a quick way by modifiying DAZ examples.

    I think the correct links are these (corrected)

    Principle is following : the camera is helping to collect light information through photon mapping

    Surface shaders must be "written" so as to read the lightning information

    For the photon mapper tech to work, your lights must emit photon

     

    Post edited by Takeo.Kensei on
  • Sven DullahSven Dullah Posts: 7,621

    Oh wooow, this is awesome, thank you so much for the links! Opens up a whole new world! I'm off to dig deep into this, see you in a couple of years, mate! smiley

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