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Shadow Catcher in IRAY

cheznous2029_28ab1adedccheznous2029_28ab1adedc Posts: 144
edited November 2018 in Technical Help (nuts n bolts)

I have read tons of post about this subject and I still am having problems getting a shadow catcher to work in IRAY.

1. Yes I chose the object I wanted to be the shadowcater, in this case a plane, selected it both in the scene tab and the surfaces tab, then applied the advance Iray nodes properties script.

2. Yes, I enabled the iray matte function for the selected object.

I do get shadows BUT I can still faintly see the plane also.  I want to see only the shadows.  There has to be something I'm doing wrong or the posters forgot to mention.

Before you say, "Turn on ground shadows in Render settings...", I am not rendering with a dome! I have a background image and my Character in the foreground, No Dome!

Post edited by cheznous2029_28ab1adedc on

Comments

  • FishtalesFishtales Posts: 6,119

    Is the plane surface set to Iray shader and cutout set to 1.00?

    I used it in this image and the method is explained two posts down from that.

    https://www.daz3d.com/forums/discussion/comment/2827886/#Comment_2827886

    Even if you are not using the dome with draw ground on you will get shadows on the ground without adding a shadow catcher. If you don't want ground shadows then turn draw ground off.

  • PaintboxPaintbox Posts: 1,633

    The shadow catcher still seems to use the material properties. Which means you must sometimes adjust the material properties to resemble the material it is mimicking.

  • FishtalesFishtales Posts: 6,119
    edited November 2018
    Paintbox said:

    The shadow catcher still seems to use the material properties. Which means you must sometimes adjust the material properties to resemble the material it is mimicking.

    I have never had to do that when I used it. It is an invisible plane that catches shadows or if you make it reflect it acts as a mirror, as I did in this image, and everything below it is shown. The background is an image, the fairy is the only geometry apart from the plane which is catching the reflection on the ice.

    https://www.daz3d.com/forums/discussion/comment/3963006/#Comment_3963006

    You can also use it to place objects behind things in the HDRI/Background image. Like in this image where I used one to get the squirrels behind the branch and one below them to get shadows on the tree.  Again this is a background image and the only geometry is the squirrels and the crow as well as the planes.

    https://www.daz3d.com/forums/discussion/comment/3282516/#Comment_3282516

    A video on using the Matte function

    Hiding behind an object.

    Hide half a figure, looks like they are crawling out of a hole.

    Post edited by Fishtales on
  • fastbike1fastbike1 Posts: 4,077
    edited November 2018

    @cheznous2029_28ab1adedc "Before you say, "Turn on ground shadows in Render settings...", I am not rendering with a dome! I have a background image and my Character in the foreground, No Dome!"

    You can still Draw Ground in Scene Only Environment mode. You also don't need to go through all of your steps to get shadows in Iray, just Draw Ground, or use a primitive plane, or use an HDRI. You can use an HDRI for lighting and still use a background image by turning off Draw Dome. You are making this much harder than necessary.

    Second image has Dome and Scene, Draw Dome: Off, Draw Ground: On, one spotlight.

     

    Capture.PNG
    659 x 540 - 67K
    test1.png
    750 x 500 - 176K
    Post edited by fastbike1 on
  • KitsumoKitsumo Posts: 1,215
    cheznous2029_28ab1adedc said:

    I have read tons of post about this subject and I still am having problems getting a shadow catcher to work in IRAY.

    1. Yes I chose the object I wanted to be the shadowcater, in this case a plane, selected it both in the scene tab and the surfaces tab, then applied the advance Iray nodes properties script.

    2. Yes, I enabled the iray matte function for the selected object.

    I do get shadows BUT I can still faintly see the plane also.  I want to see only the shadows.  There has to be something I'm doing wrong or the posters forgot to mention.

    Before you say, "Turn on ground shadows in Render settings...", I am not rendering with a dome! I have a background image and my Character in the foreground, No Dome!

    Even though the matte surface is mostly invisible, it still has it's normal properties like glossiness, speclular, etc, so you'll have to turn those off. In most cases, that's what you're seeing, light reflecting off the matte surface. Did you convert the matte surface to an iray shader? It's not mandatory, but I think it helps.

    I tried a test render with the conditions you described and it worked fine. I can't imagine what else could be happening. I guess as a last ditch effort you could set refraction weight to 1 and refraction index to 1. That makes your plane pretty much see-through like glass, but the matte function should still catch shadows.

  • AbnerKAbnerK Posts: 718
    edited May 2022

    I suppose this is old news now.

     

    Thanks

    Post edited by AbnerK on
  • FlortaleFlortale Posts: 611
    jimmac-donald said:

    The Shadow Catcher doesn't seem to be working properly in 4.12. I haven't used one for ages. In MEC's video it's suggested to make the Base Colour of the plane black but if I do that I get no shaddows. I get shadows when I make the plane white but I also get a white 'glow', see attachment. I've tried turning off anyhting with 'gloss' in it as well as reflections. I've made everything slot black. I must admit. I don't have a pratical example of this at the moment. I'm trying to understand it for when I do and was trying to explain to someone else what to do which made me realise it wasn't working as it should now. 

    Thanks

    I'm having the same problem. Shadow catcher does not work in 4.12.

    Here are my results:

    The plane with the Iray Matte enabled always shows slightly.  The above image has a purple layer added so you can see the plane.  If I remove the purple layer, the plane is much harder to see, but still there.   I have another post here in which I discuss this issue. If anyone can help it would be greatly appreciated. We need to get this shadow catcher working properly with 4.12: 

    https://www.daz3d.com/forums/discussion/384096/i-can-t-get-a-distant-or-point-light-to-cast-a-shadow-on-a-scene-only-ground#latest

  • tailz_b5babac3c2tailz_b5babac3c2 Posts: 2

    Was there ever a solution to the "grain" on the shadow catcher object? I even get grain when just using the render ground feature to act as a simple shadow catcher in Iray.

    Don't have the "grain" problem in 3Dlight, which gives a far nicer alpha transparency for a captured shadow. Just annoying having to do a separate pass in 3Dlight just to capture a shadow plate.

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