Digital Art Zone

Journey 04: Additional Comments / Questions from the Original Posts

1) Harry Dresden asked:

Q: Have you experimented with intensity levels when used in conjunction with other lights? I’m thinking this is more useful for light effects (like IDL) than a main source of light but I’m struggling to figure out how not to over-light my scenes when using this.

A: Absolutely. That’s my “default” setup. I run UE2 at 45% Intensity and use 2(or 3) pt distant lighting to supplement it for outdoor renders. I setup the main distant light (key light) at 60-75% intensity depending on how bright the scene is supposed to be. I setup a specular boost light (lighting mode specular only) at the same angle/orientation as the key light. I put it at 45% intensity to offset the quashing of specular response that UE2 creates, and then I use either a back light or a bounce light depending on the scene needs. That’s usually at 20-50% for back lighting (depending on how much “rimming” I want) and 20-30% for bouncing. Bounce light is roughly at 90 degrees rotational offset from the key light and at a VERY shallow angle (like no more than 15%). Oh and another trick… each additional distant light needs a “higher” shadow softness percentage than the previous one. If you don’t do that you’ll get “studio shadows” where you see shadows running off in every direction. However, if you DO make them softer than the last they’ll layer almost invisibly.

That’s also what I do most of my “DS MAT” development in, except in the latter case I also make sure that all the lights are set to pure white.

You can grab a light preset that I saved out if you just want to load them by clicking here. Just unzip them to a DAZ Studio Native content directory and look for them at ~\Lights\AMR\AMR UE2 Presets\Pure White for MAT work.dsa

2) SiliconAya asks:

Q: With indirect lighting is there a reason why it’s so slow? With Poser 8/pro 2010 rendering a pin-up kind of scene with IDL at worst doubled the render time, but generally only added a minute or 2, with DS4 and UE2/UberSoftLightKit at best it increases render time by 20 or 30 times and often a lot more. Last time I tried IDL I gave up after 30 minutes with nothing being rendered, when the same scene rendered in about 2-3 minutes without IDL turned on.

Is it a problem with UE2, DS, the way DS uses 3Delight or a combination of all of them?

I’m thinking it isn’t a problem with 3Delight itself as it’s such a high-end commercial grade renderer and so well used in industry, but I guess it could be.

A: Yeah, it’s partly 3Delight (which does not handle transparency very efficiently) and partly a function of how UE2 is just a light providing global Ambient Occlusion, Raytracing w/Bouncing. That’s three complex sets of math that have to be dealt with. One trick to make IDL faster is to lower the Maximum Trace Depth (how far out raytracing / bounces / occlusion must be calculated). Another is to use UberSurface to exclude unnecessary items from Raytracing / Occlusion.

FWIW: 90% of my “final quality” renders take 2-3 hours. Another 2-3% take less than that and the remaining 7-8%? Yeah, they take more. Sometimes much more.

3) d-username asked:

Q: i did some test renders and still seeing some grain in the shadow areas, not bad but

IDL w/Directional shadows mode
UE2 preset 4XHi

3Delight Render Settings
Shading Rate: .20
Shadow Samples: 16 a later version i used 64 and it did not seem to add that much to render time

Questions
- what settings would be best to lower the grain
- do you use extra lights in the IDL mode or is UE2 enough?

A: If you’re using UE2 as the only light, then you need to lower the shading rate on the parameters tab for UE2 itself as the default Shading Rate even at 4xHi Preset is 8.00 which is fairly high.  When using UE2 as a standalone light source start with a shading rate of 1.00 and go down from there. This isn’t usually necessary if you’re using UE2 with helper lights. 

4) MrPoser asked:

Q: I have been trying to learn Uberenvironment2 along with DS4. I am also not real familiar with IBL so I was wondering if you could talk a little about the color parameter and the associated map. Looks like the maps are always 2w x h but are there other restrictions if we want to play with other maps? I have read you can make the color grey if your render is too bright?

A: Glad to talk about it.

Yes, the standard image map format for all the uberlights to use as gels is 2w x h. UberPoints, UberSpots and UE2 itself all follow that guideline. I believe the only other limitation is the standard 10000 pixel limit on DAZ Studio itself… so the biggest map would be 10000 x 5000. That might be important or might not. I’ve never used anything remotely that large myself. Usually 4000x2000 or less. If the image map was used in Reflections (and IMO it should be) then the map size would be more important, but as it stands currently the image map does NOT show in reflections so its quality is of less importance.

What I can tell you about the Color mask for the image map of UE2 is that it acts as a filter against the image map. Keeping it grayscale will let you adjust the intensity (brightness) of the map. Going into colors gets into some weird fun additive (or possibly subtractive, but pretty sure it’s additive) math. I’d honestly have to experiment with that some. It should be fun though. Basic premise would be to make, oh, say, a Green Square in a white field. Then use a Yellow tint on the diffuse color for the map, see if you get blue or if you get a different green (additive vs. subtractive).

5) Bendinggrass asked:

Q: I read through your work on this, but I need something much more basic, from the start, on how to even begin to use lighting in D4.  Could you recommend something please?

A: Old, but still relevant: http://digilander.libero.it/maclean/DStutorial.htm This tutorial remains one of the best all time tutorials for getting started with lighting.  Everything it contains is still applicable in DS4.

6) wiseavatar asked:

Q: Anyone getting a disparity between the preview environment sphere and the actual orientation of the map?

This especially is evident when you want to use environment mapped reflections and uberenvironment and the sphere as a background.

To clarify I am not rotating the sphere independant of the light.

A: Here’s what I’ve noticed… the Sphere that comes with UE2 is oriented correctly. If I used a primitive sphere, I have to do all sorts of machinations to get it to align correctly.

When I went to render it, I return the Sphere primitive to full scale (making it 250m in size), then lowered it on the Y-Axis by -12500 cm (125m) so that it would be centered on the ground plane. Rendering it with a small reflective sphere in the center initially made me believe that the sphere was not reflecting the Sphere Primitive (sky dome) because the Trace distance was too low.  This turned out to be incorrect.  The solution to the lack of reflection was to set the Sphere Primitive (sky dome)‘s Ambient Color to 255,255,255 and Ambient Strength to 100%.

7) cipher_x asked:

Q: I also noticed a parameter to set Shadow Type to: None, Shadow Mapped or Raytraced. I tried it and it did render different types of shadows. By default the Cast Shadow is set to on but the Shadow Type is set to None. Is that the way it is supposed to be?

A: You have hidden parameters enabled. The following parameters (and their default values) are not meant to be altered:

Cast Shadows: On
Render Priority: Normal
Point At: None
Shadow Type: None
Display Persistence: Off
Ray Length: 2.50
Opacity Scale: 100%
Ray Opacity: 15%
Show Base: Off
Base Opacity: 15%
Show Edge: On
Edge Opacity: 20%
Sphere Diameter: 2.50
Opacity: 15%

Please let me know if you guys have questions and I’ll do my best to figure out the answers.

Thanks!

Seems obvious now that I take the time to think about it - IDL is cooler than mere occlusion. I wish I’d found something like this when I first started with Studio. Took me long enough to find Uberenvironment, let alone what to do with it. Many thanks Adamr,

You are most welcome.

adamr001 - 08 August 2012 10:56 AM

Cycle through those a few time in your favorite image browser… You can watch the effect pretty easily. What it’s really doing, as I mentioned before is affecting the saturation of the color in the HDRI map. This works pretty much like Image Saturation Control in your favorite image editing software. Reducing the saturation to 0% effectively makes it grey scale. This has a fairly big impact on how the rendering engine determines what is casting light and what isn’t and I believe is what causes the overall “decrease” in the intensity of the shadows (how dark they are) because more things are being considered as light sources.

So I think I understand what Saturation does, though the when and how of its application is still something I’m considering. I think, ultimately, that you’d probably choose to reduce the saturation if you found the results of your Environment Map to be too harsh. Lowering it would create a smoother more balanced image.

Hi Adam. Great work, its helping me a lot to understand UberThings, and why the image I’m rendering is already 20 hours going ((:

I think Saturation and Contrast refers not to the object color, but to the shadow color.  Check this image, I got the red ball from your examples with Saturation 0% and 100% and the red is exactly the same on both. What is changing is saturation on the shadow (and bounce color I think)  EDIT: No, not bounce color, it appears stronger on the 0% saturation image because there is less shadow on top of it.

Try this, bring up your UE2 environment map in Photoshop.  Desaturate the image.  Save it as a new file and load that in to UE and see.  I’m reasonably certain on this one.

adamr001 - 19 November 2012 10:03 AM

Try this, bring up your UE2 environment map in Photoshop.  Desaturate the image.  Save it as a new file and load that in to UE and see.  I’m reasonably certain on this one.

Then why red is the same on both 0% and 100% saturation?

2Fatbear - 19 November 2012 07:00 PM

Then why red is the same on both 0% and 100% saturation?

Because we’re talking about the Environment Map not the object’s diffuse map/color.

adamr001 - 26 November 2012 01:59 PM

2Fatbear - 19 November 2012 07:00 PM

Then why red is the same on both 0% and 100% saturation?

Because we’re talking about the Environment Map not the object’s diffuse map/color.

Exactly, the saturation refers only to the shadows and not the complete image like when we use saturation in photoshop.

Now contrast I will need one year or two triyng to figure (:

{}fatbear