3Delight Laboratory Thread: tips, questions, experiments

Mustakettu85

Zarcon, I know there is something wrong going on with your viewport when you try gamma correction, but pleeeeease don't confuse people by saying it's complicated =) Linear workflow in DS+3Delight is super easy. You just enable the "gamma correction" switch, make sure all colour maps have a "0" in the little "image editor" box, all control maps (bump, opacity, normal, spec strength...) have "1" there (95% of the time DS guesses correctly; I think recent builds started handling opacity maps much better as well); and then you set the tonemapping curve (the "gamma" value in render settings) to 2.2.

Done =)

Of course people like me render to EXR and then tonemap in external apps, but the point is, textures have to be linearised correctly beforehand, and DS does it really well. It will also handle colour pickers and the like.

...there are potential issues regarding embedded profiles in jpeg files, but they are not that huge as compared to the overall benefit.

Oso3D

Hrmph.

I thought I had come up with a wondrous new idea to quickly generate 'realistic' lighting and pick up lots of light sources by using Ambient color plus making all surfaces blurrily reflective.

But I think all I've done is reinvent meshlights, and I'm not sure there's an actual savings over meshlights once you crank reflection blur samples high enough to look decent.

 

On the other hand, I really like the look you get with everything being somewhat reflective as somewhere between typical specular 3dl and PBR.

 

 

Oso3D

Ok, so my current noodling, trying to realify 3DL without blowing past Iray CPU slowness...

I'm finding a LOT of bang for my rendertime buck by swapping specular for reflection. It slows things down, but the 'win' of effectively grabbing bouncelight-like results is huge; stuff looks way more realistic for (guesstimating) 50% more rendertime.

Moreover, if you have lamps and other ambient stuff, and increase reflection fidelity (I find maxpath 3 and at least 64 samples does a credible job in an otherwise decently lit scene, maybe a bit more samples sometimes), you can capture the effect of those lightsources on surfaces. They look 'lit'; this isn't a perfect approach, because you end up increasing processing by 'lit' polys rather than emissive polys.

What I'm finding is a good combination with arealight (meshlight); I'm learning to use meshlights more effectively. You need to balance falloff so the light goes far enough for your purposes as well as samples so things don't look too grainy (unless you want grainy!)

 

Using reflected ambient surfaces + arealight, I don't need things like UE2 or AoA Ambient (with occlusion). That saves me more time than the approaches cost, I think.
 

Mustakettu85

Have you tried using UE2 in combination with the point cloud occlusion script? It won't do raytracing then, just point cloud. And you can use IDL/bounce then, point cloud doesn't really care.

It will only give one bounce, but since you get all that indirect specular, it may be enough. Besides, ambient surfaces will turn into noise-free emitters then,

Oso3D

I don't really do script or other more involved stuff... bunch of space magic. ;)

And I've been so annoyed trying to use UE2 I just avoid it.

 

Mustakettu85

It's a premade script, comes with DS. The only magic there is disabling the "simple occlusion light" =)

When you get over the annoyance, you could give it a try in conjunction with that script. Kinda redeem it in your eyes =)

Oso3D

Ok, I'll bite... what's a point cloud?

(And oh what a shock, official wiki documentation is useless)

 

Oso3D

I'm incredibly excited to announce Esemy has made a great Iray -> 3DL converter script. Free.

It works fast and converts nearly all 'regular' Iray stuff. You'll still need to fiddle a bit with glass and emissive stuff, but that's to be expected.

http://www.daz3d.com/forums/discussion/139326/irayto3delight-conversion-script

Mustakettu85

timmins.william said:

Ok, I'll bite... what's a point cloud?

(And oh what a shock, official wiki documentation is useless)

It's a specific math thing you don't need to know anything about to actually use the script =)

But if you're curious, the renderer creates a representation of the scene geometry that is made out of points. This is why it's called point cloud. These points carry some precomputed values that the renderer later interpolates between.

So, get the "Scripted 3Delight" mode from the dropdown in the render settings. Then in its "render script" dropdown, find the "Point-based occlusion" one and select it.

You get your "conventional" render settings, and two more headings on the left.

Don't forget to set your pixel samples, gamma etc in the "conventional" render settings.

You'll see a "simple occlusion light" heading. Go there and disable it. Load an UE2 into your scene. It is hardwired to pick up the specific point cloud created by this script. It can use it for AO or IDL, and here IDL is what we want, so set UE2 to an IDL mode (soft shadows is best if you aren't using an HDRI in UE2).

You will use "occlusion samples" and "shading rate" controls of the UE2 to get better quality render. And of course, for GI you should increase max distance from its measly 5 meter default distance.

Then under the "Point Cloud" heading you'll see various settings. You can keep them the way they are, but I would set hitsides to "both" to catch bad normals.

Point cloud effects will look slightly different from raytraced effects, but still. Can be twice as fast.

// in this test render the walls and the sphere have ambient on = are slightly emissive; UE2 colour is black, so effectively there are no other lights but the emissives //

Scripted render settings can be saved into a render settings preset just as well as any.

The only problem with this script as-is is that it calls the REYES module not the raytracer. But it's a one-line fix. So if you need it, just ask.

Oso3D

That sounds fabulous. Does that 'fake' light go through transparencies (like a lamp shade)?

Mustakettu85

Yes =) Takes longer, though. UberSurface "occlusion override" settings on the transparent stuff might help.

 

Oso3D

Very interesting.

I tested the 'convert Iray to 3DL' script on an interior which had a bunch of light bulbs and lampshades and was a bit... thrashing about trying to figure out how to handle it properly. I think I may give it another shot with this.

Thanks as always for your great help!

Mustakettu85

You're welcome! =)

Oso3D

So ... what's the one line? And where are the render scripts?

 

Mustakettu85

So the script should be someplace like here:

C:\Program Files\DAZ 3D\DAZStudio4\scripts\support\DAZ\ScriptedRenderer\Point-Based Occlusion\PointBasedOcclusionRenderScript.dsa

Open it in something like Notepad++ (any coder-oriented text editor will do, not MS Office) and go to line 69.

Lines 64-68 should be:

/*********************************************************************/function setupRender(){	// Begin describing the render	Renderer.riBegin( sRIB );

And after them you put the following:

	// Kettu: herewego		aTokens = [ "integer progressive", "float aperture[4]" ];		aParams = [ 0, [0, 0, 1, 1] ];		Renderer.riHider( "raytrace", aTokens, aParams );	// end of edit

Then save (admin access needed if your DS is also in a protected folder).

Then 3Delight will start using the raytracer here as well. It will slow down the extra simple scenes like this one (28 seconds instead of 16), but when you add raytraced reflections and shadows, this should help.

This calls the raytracer that can use all the filters, not just the box that the progressive mode is limited to. But if you do want progressive, then take a look at aParams: the first zero in aParams is progressive on/off. You make it 1, it will be progressive. I haven't tried how well it plays with point clouds, though =)

Oso3D

Wow, I'm an idiot. I had no idea UE2 IDL made ambient channel into light source.

... ... .. duuuh.

 

Mind you, it's still awfully grainy. Mmm.

 

Mustakettu85

Any indirect light will make ambient into a light =) It's just that without the point cloud, they will need a huuge number of GI samples not to be grainy. Like, over 1000.

With the point cloud, upping the UE2 samples to the max and dialing its shading rate down helps. Without the point cloud... it's probably going to make it render foooorever.

PS The default max of UE2 is 128. You could always kill the limits, of course.

Oso3D

aaaaaah.

Ok, let's see if I can get this turkey to some happy middle ground of rendering reasonably fast and not looking like a 1920s camera

 

Mustakettu85

It's been ages since I rendered anything with UE2, so I can't say what is the faster way to get less noise: increasing pixel samples (general render settings) or UE2 samples. Or if pixel samples really help much with UE2...

Either way, UE2 also has "max error" that can also be decreased. I never tested which one gives the best bang for the buck, though.

Oso3D

Occlusion samples seem to deliver the bang for the buck over everything else I've fiddled with, and it lets me easily dial in 'good enough' vs time.

 

Oso3D

Ok, thanks to the great advice, I managed to do this just using UE2 and point occlusion in about 10 minute render time.

(There's a weird black outline around some of the lightsources which I hadn't seen earlier, not sure what's up with that, but regular post work got rid of most of it)

 

Mustakettu85

Awesome Dalek intruder! =)

Those black lines are filter "ringing" that happens with some filters when there is too much contrast - the lights are way brighter than everything else, and the filter creates these annoying lines. If you look closer, you'll see there is a white line outside the black one.

Let me guess, you're using the sinc filter with something like 6x6 width, the "default"? Sinc gives sharp pictures, but at the cost of this "ringing".

I personally have abandoned wide sinc in favour of a narrow Catmull-Rom (2x2). Helps with these contrast-y places a _lot_, and doesn't really add blur in high-freq stuff like hair.

Mustakettu85

Here are filter "reference charts" I made for the docs to my in-the-works stuff. Sorry for spellchecker lines, these are quick screenshots from LibreOffice =)

 

Oso3D

I had tried other filters but the ones I tried looked meh, glad for the tip.

 

Oso3D

Another weird thing I'm getting with some Point Occlusion/UE2 stuff is a lack of close-range 'glow.' Like, in the Dalek corridor thing, there's a nice glow on surfaces near the ambient sources.

But in a bunch of other cases, that glow seems missing. I'm... kind of baffled by it.

 

Mustakettu85

Could the underlying surface be too dark? If it's close to 0, then it will "eat" all the light that falls on it (because surface colour is multiplied by the light, so it's easy to make a "black hole").

Oso3D

Aaah... the specular may be too dark. That could be it.

 

Oso3D

Oh for fred's sake.

yeah, most of the surfaces were Daz standard shader Matte.

...

 

Mustakettu85

And just in case, you could try decreasing the point cloud shading rate, if you find that some tight corners get too dark or conversely if there is strange light leaking. It will make the cloud more dense, so the nooks and crannies are better covered. 

Oso3D

It seems that AoA Distant light wasn't playing nice with either UE2 or Point Cloud Occlusion. That's no big deal, I can set aside different tools for different set ups.