I can't get a Distant or Point light to cast a shadow on a Scene Only ground.
Flortale
Posts: 611
I can't get a Distant or Point light to cast a shadow on a Scene Only ground.
I'm using IRAY.
I create a new scene.
I load Genesis 8 Female.
Under Render Settings, I set Scene Only and Draw Ground is Enabled with Ground Shadow Intensity set to 1.
I have one point light in the scene which lights Genesis 8 just fine, but no shadows are cast on the ground.
What am I missing here?
EDIT: I managed to get the Distant Light to successfully cast a shadow on the ground, but I cannot get a Point or Spot light to cast a shadow on the ground, even though it casts a shadow just fine on a plane primitive. Please help me get the Point & Spot light to cast shadows on the Environment drawn ground.
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I have here a plane, with the Advanced Iray Node Proerpties applied and Enable Iray Matte on, a regular cylinder, and a point light. Enviroment Mode is Scene Only, Draw Ground is Off, Shutter speed is 32, ISO is 1600.
I'm going to add more information, since it's vital I get shadows cast on either a ground drawn by the Environment render setting or an invisible plane.
As you can see here, I can get a point light to cast a shadow on a normal plane:
If I hide the plane, a shadow does not get cast on the ground drawn by the environment:
If I use a distant light, I can get the cylinder to cast a shadow on the ground drawn by the environment:
If I apply Create Advanced Iray Node Properties from the Utilities menu to the plane, then set Enable Iray Matte to on, a shadow does not get cast on the plane when visibility is set to off:
However, if I set it's visibility to on, it does cast a shadow....
... but the above defeats the purpose. I need only the shadow cast from a point light and the model to render, not the plane in anyway.
Can anyone please help me figure out how to get a point light to cast a shadow on either the ground generated by the Environment tab or an invisible plane?
With the Iray Matter the only bit of the plane that rnders is the area with the shadow - the non-shadowed areas are invisible (as long as you save as Tiff ro PNG, of course).
So even though I can clearly see the plane in the render, if I save it out to a Tiff or PNG, the plane disapears? I'd test it right now, but I can't close my DAZ project since I'm connected to Zbrush via Goz. I'll test this first thing tomorrow. I really hope this works, thanks.
That should be true, unless soemthing else is affecting the plane.
Sadly the plane is still visible. I made sure the surface doesn't have any gloss, top coat or dual lobe specular. It looks like there's no way to cast a shadow from a point light onto a drawn ground by environment or on an invisible plane using the Iray Matte Enabled technique.
I'll have to ask if anyone knows of a shadow catcher that works with 4.12.
I opened the renders in Photoshop and the plane is still barely visible. Here is what the end result looks like in photoshop. I had to save the render as a tiff to even get it to look like this, png doesn't work.
Looks like success right? Nope, the plane is still there. If you put a green background behind it, you can see the plane still exists.
I'll keep doing researcher into a shadow catcher for 4.12. If anyone can figure out this dilemma please let me know.
Anyone know of a shadow catcher for 4.12 that works with point lights?
Basically, I need to be able to render a cylinder whose shadow is cast on the ground from a point light, and nothing else should exist in the render, the rest transparent, then save that render to PNG.
It should look something like this:
(This is a fake mockup of what I need.)
Before anyone links me to the IRAY Matte Enabled method, it no longer works with 4.12 if you use a point light. If you do manage to get it work, please leave instructions on how you did it.
Maybe there's a lot of scattered light from your cylinder - mine has a halo around its base for that reason - but I don't see the plane. Here are two renders of the same set-up, one a plain render with no Iray Matter enabled, the other rendered with the plane an Iray matte and then background elements added in an image editor.
And don't forget to check the shadows setting for the light. Also take the light source to like 10,000x BRIGHTER to see if you get different results.
Are you using distant, spot or point light?
Can you explain step by step how you achieved your results? I spent hours trying to get it to work, no matter what I did, I could not get a point light to cast a shadow on the plane with Iray Matte Enabled.
It was a point light. I used that and the cylinder as created, I edited the properties of the plane to kill all the glossiness, environment was Scene Only, Tone Mapping was 32 for shutter speed, 1600 for ISO. This was in the current Public Build.
Richard, I'm going to list exactly what I did, and perhaps you can tell me what I forgot to do?
I create a new DAZ project.
1. I set Environment mode to Scene Only.
2. I create a cylinder and plane primitive.
3. I add a point light with luminous flux set to 300,000 and position it so it casts a nice shadow.
4. I apply Create Advanced Iray Node Properties to the plane primitive, then select the plane and set Enable Iray Matte to On.
5. I click Render.
6. I export both PNG and TIFF (which required two renders)
No matter what I do, I cannot make the plane invisible. The shadow strength also diminishes severely. This has a green layer added in photoshop to show the plane is still there.
Here is how my scene looks, the viewport is rendering IRAY:
Here is my point light settings, I changed nothing else.:
Environment setting, all other IRAY render settings at default:
The point light has it's luminous flux set to 300,000 to make sure it lights things properly. The shadow settings I leave at default since it's an IRAY render.
No matter what I do, I can't get it to work. This is so frustrating. It's such a simple thing, how could I possibly mess it up.
I'm willing to use another product, but no one seems to know of a shadow catcher that works with 4.12 ... My question got moved to this post, so no one will see my request. I need to render a character and have a shadow cast on the ground from a point light, why is that so god damn hard. This sucks.
The plane is still visible and the gloss is still set to 0.33 on the plane, so it has a slight reflection.
I'm not seeing any proeprties set to 0.33 in the scene I attached to my last post (which is newer than the image, that was a different scene from last night), even with Show Hidden Properties enabled. Your light is much brighter than mine, but you are presumably using the default Tone Mapping so that shouldn't matter much.
You don't need me to tell you that default primitives have an IRAY surface and have a Glossy Layered Weight of 0.33 by default. You already know this. You're probably really busy answering tons of other questions. You're very helpful on the forum. I learned lots from you!
I forgot to add an image.
This is your render. I copy and pasted it into photoshop. You can see the reflection and plane:
Another guy reported this same problem for 4.12 : https://www.daz3d.com/forums/discussion/comment/4125546/
You may have overlooked Richard's comment that he "edited the properties of the plane to kill all the glossiness". That is why his plane no longer has the default Glossy Layered Weight of 0.33.
Just applying Create Advanced Iray Node Properties is usually not adequate when working with these advanced features. Tweaking the surface settings is also very helpful. The Matte surface can be used for more than a shadow catcher. For example, it can be used to create a reflection to show up over an HDRI background (a technique also described by Mec4D). In that case, you want to turn UP the reflective/glossy properties of the surface, not turn them DOWN. So, the required surface settings depend on your intended use of the Matte surface.
However, I can see that Richard's adjustments, while very helpful, may still not be enough. I rendered his scene and put a dark green background behind it in Photoshop as you described. The plane is still slightly visible. Setting the plane's Glossy Reflectivity to 0, will also help some more, but the plane is still slightly visible over the green background. I think when used in a render, over a less uniform background, like over an HDRI background, the plane will not be very noticeable.
I tried Richard's scene in DS 4.11.0.383 and the results look the same as the DS 4.12.1.55 results. So, I don't think the issue is any change in DS 4.12.
Hmmm. I'm a little bit confused now, because when I reopened Richard's scene, Glossy Reflectivity was already 0. I don't know at what point I thought that was not 0, but I definitely got a different result when changing it. I probably made a mistake somewhere along the way.
If you guys open Richard's DUF project file, he lights the scene in a different way.
I was setting the point light's Luminous Flux to 300,000. However, Richard uses Exposure Value, Shutter Speed, and Film ISO to get the scene to light up. His point light's Luminous Flux remains at the default value of 1500. If you set the Luminous Flux to 300,000, and then restore Exposure Value, Shutter Speed, and Film ISO to the defaults, the plane remains highly visible, which is the problem I was describing.
Using his method, the plane is barely detectable, making it a working, viable solution. So the Iray Matte method does work, but you have to light your scene using the Tone Mapping values instead of increasing Luminous Flux on the point light.
I have to research lighting a scene using Exposure Value, Shutter Speed, and Film ISO, instead of a higher Luminous Flux value on the point light. What is the professional, official way to light a scene for IRAY? Tone Mapping or increasnig Luminous Flux? Anyone know by any chance?
I'm coming to this pretty late but for the record I do see the same issue as you with a Point Light + virtual ground Shadow Catcher. Switch the Point out to a Distant & tilt correctly and it works.
But Spot doesn't either.
So BUG. That should work for ALL lights or NONE. And since it works for one ...
Even so, rendering out a png from Richard's DUF, simply viewing or opening depends out what you're usivng; there still are some fuzzy areas for how some apps handle pngs. See the attached.
I don't have Photoshop on this system and one plug I've used for years & really miss, used specifically for PNG's is Fnord's SuperPNG. https://www.fnordware.com/superpng/
Snag that & see if that works better for extracting than just native Photoshop.
Beyond that Flortale, some of your requirements go unexplained & are a bit confusing frankly.
WHY does it HAVE to be a point light for example? I'm assuming your wanting a perspective shadow.
Why can't you use geometry again? You see the edge of the plane? Even a 1000m. plane?
What is your actual end goal? There may be other simpler, easier ways to get there if we knew what that actually was. It really isn't Rocket Surgery.
I'm down for using geometry to light the scene. I eventually planned to try Ghost Lights, and I think those are geometry based right?
In this image, you managed to catch the shadow. Did you use a geometry light for this scene? These results are totally acceptable.
Is anything lost when using geometry lighting vs point light? Thank you for taking the time btw, same to Richard.
Definitely something goofy going on with how Iray matte works now with the various lighting options. Is it a bug or is it intended?
Daz v4.12 (tried in both the production build and current public beta 4.12.2.6)
1) Create new scene
2) Set environment type to backdrop, change backdrop color to any hue (a high saturation value is best)
3) Create plane primative at 0 coordinates (this will be the object catching shadows)
4) Create sphere primative at 0 coordinates (this will be the object to cast the shadows)
5) Change sphere surface shader to Iray->Metal->Metal Chrome
6) Create Distant Light, rotate X axis to -75
7) Create Point Light at coordinates xyz(500,500,0)
8) Create Spotlight at coordinates xyz(-500,500,0) rotate to point at sphere xyz(-90,-45,45)
9) Create cube primative at coordinates xyz(0,500,500)
10) Change cube surface to iRay emmissive
11) select plane and apply the iray advanced node properties script
12) enable iRay matte in the plane's display properties
13) set luminal flux value to each light.
...
each light seems to need a very different value
despite being equal distance from the object
-->distant = 150,000
-->point = 3,000,000 (not a typo, set it to 3 million)
-->spot = 300,000 change spread angle to 45
-->cube = 3,000,000 also change temperature value to 6500 to match the other lights
14) disable all the lights (distant, point, spot, emissive)
15) in rendor settings, change environment mode to scene only and turn off 'Draw Ground'
16) change to iRay preview mode and begin the tests.
First of all, with no lights enabled, i would expect the sphere to be completely black, but something is causing the backdrop to illuminate and reflect onto the sphere. Where is the light coming from? i thought maybe perspective view is doing a sneaky headlamp, but i get the same result viewing through a camera with headlamp set to off. Curiously the backdrop is reflecting onto only the lower half the sphere acting like a ground plane.
Now, enable each light separately one by one.
with the distant light, everything looks perfect. shadow is well defined and i do not see the plane at all except for a slight reflection of the sphere. (this reflection can be easily removed by setting the plane's glossy layered weight to 0). This is exactly what i would expect from an iRay matte surface.
now try the point light, spot light, or emmissive light.
very very different results. the plane become highly visible, the shadows are not as well defined as the ones created by the distant light even with the high luminence values used.
it is possible light hitting the sphere could bounce off it and illuminate the plane but not at the levels we are seeing. the lights themselves seem to be illuminating the plane directly.
change the plane's base color value from 255 to 128, the shadows become weaker and the reflection becomes stronger
change the plane's base color value to zero and the shadows dissappear completely and the reflection becomes mirror-like. adjusting the glossy roughness can smooth out the reflection, but where did the shadows go?
even when setting the plane's base color and glossy color to match the background environment color the plane is still very visible when under point, spot, or emmissive light sources.
only distant light seems to work correctly with iRay matte. i dont recall this ever being like this in previous versions of daz but i dont have a way to verify that.