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Need clarification on Raytrace Shadow attributes...

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Message 1 of 18
hilaire.gagne
1493 Views, 17 Replies

Need clarification on Raytrace Shadow attributes...

Hi Folks,

 

Many controls in Maya can go beyond the slider limit by simply entering a larger value.  I typically spend some time searching the Maya documentation and online (aka Internet) before increasing values beyond the slider control default limits.

 

At the moment I am stumped on the "Raytrace Shadow Attributes" slider limits; specifically those associated to the "Use Ray Trace Shadows" options.

 

The documentation seems to imply that the maximum limit to "Light Radius" is 1 (soft shadows) and that the maximum limit to "Shadow Rays" is 40.  Many online tutorials that I have watched/read typically enter numbers significantly greater than those noted in the documentation.

 

Could someone be so kind as to set me straight?  For example, are the limits in the documentation specific to certain conditions (ex: Linear Color Workflow, etc.), is the documentation simply stating that these are the initial (default) values, etc.

 

Advance thanks,

 

Refrence:

http://download.autodesk.com/global/docs/maya2014/en_us/files/Lighting_nodes_Shadow_attributes.htm

___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

17 REPLIES 17
Message 2 of 18

* UPDATE *

 

Looks like the link to specific pages in the Online Help for Maya 2014 isn't working ...

 

http://download.autodesk.com/global/docs/maya2014/en_us/index.html

 

> Lighting and Shading > Lighting > Lighting Reference > Lighting Nodes > Shadow Attributes

 

 

 

___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

Message 3 of 18

Started a thread on this at CGSOCIETY (http://forums.cgsociety.org/showthread.php?f=7&t=1114860) and have received some replies so I figured I'd add the thread reference here.

 

* NOTE *

 

Would have simply editing my first (or second) post in this thread but for the life of me, I can't seem to find the "Edit Post" option.

 

 

___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

Message 4 of 18

Re editing posts. At the top, on the right, level with the thread Topic, is an Options drop-down. Click that then choose Edit Message.
Likewise with replies - the Options are to the right of the topic shown above each reply, the Option to edit is Edit Reply.

Max 2016 (SP1/EXT1)
Win7Pro x64 (SP1). i5-3570K @ 4.4GHz, 8Gb Ram, DX11.
nVidia GTX760 (2GB) (Driver 430.86).

Message 5 of 18

Hi Steve,

Strange, I only have the following options available on the drop-down menu of my posts after logging in:

Mark As New
Bookmark
Subscribe
Subscribe To RSS Feed
Highlight
Print
Email To A Friend
Report Inappropriate Content

and on Replies, an additional option:

Accept As Solution
___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

Message 6 of 18

You don't see "Edit Message" immediately above Mark as New? I just tried it with an alternative (non-moderator) account and the option is there. Unless there's a timeout after which you can't edit then I don't know why you're not seeing it.

Max 2016 (SP1/EXT1)
Win7Pro x64 (SP1). i5-3570K @ 4.4GHz, 8Gb Ram, DX11.
nVidia GTX760 (2GB) (Driver 430.86).

Message 7 of 18

Nope ...

 

screencap.jpg

___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

Message 8 of 18

Not sure. I'd suggest you post in the Website Support Forum. Include the image from the post above.

Max 2016 (SP1/EXT1)
Win7Pro x64 (SP1). i5-3570K @ 4.4GHz, 8Gb Ram, DX11.
nVidia GTX760 (2GB) (Driver 430.86).

Message 9 of 18

I guess the folks at Autodesk don't frequent these forums too often ...

 

Well, contrary to the Maya documentation, I started experimenting with values >1 for Light Radius on a Spot Light as I couldn't find any other way of obtaining soft shadows on objects as they were further away from the source light.

 

I'm going to start assuming at this point that the Maya documentation hasn't been updated for quite some time and that it's mostly 50% accurate and that trial & error, online searching, and various book reading will have to fill in the other 50%. Smiley Sad

___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

Message 10 of 18
remydrh
in reply to: hilaire.gagne

I will make a suggestion here if you're using Maya 2014 that should keep your render times low and your settings minimal, take a look here:

 

http://elementalray.wordpress.com/2012/03/19/area-lights-101/

 

These options for samples apply to the point lights (spot, etc) as well.

Message 11 of 18

With reference to editing posts there's a short period, after creating the post, during which you can edit that post. After that (around 15 mins), or if the post has been replied to, then you can no longer edit the post. I wasn't aware of this until I asked about it - facilities on these forums (for members and for moderators) aren't the same as those on the old ones. Apologies if I caused any confusion.

Max 2016 (SP1/EXT1)
Win7Pro x64 (SP1). i5-3570K @ 4.4GHz, 8Gb Ram, DX11.
nVidia GTX760 (2GB) (Driver 430.86).

Message 12 of 18
hilaire.gagne
in reply to: remydrh


@remydrh wrote:

I will make a suggestion here if you're using Maya 2014 that should keep your render times low and your settings minimal, take a look here:

 

http://elementalray.wordpress.com/2012/03/19/area-lights-101/

 

These options for samples apply to the point lights (spot, etc) as well.


Appreciate the reply and thank you for taking the time to research a link to an indispensable site ... I had this bookmarked from my ongoing searches. 🙂

 

When I opened this thread, I was looking to understand why seasoned folks who have shared their knowledge via tutorials/walkthrough use values that are significantly higher than what the documentation recommends.

 

Although I cannot find any reference or mention in the documentation - or on various reputable website resources (blogs, CG Society, etc.) - I am noticing that if I change the shape of an Area Light to be non-uniform, the render times literally double.

 

For example, I sized an Area Light to simulate Bounce light of a counter top (ex: 6 x 20) and observed that render times increased dramatically.  I changed the configuration to 4 Area Lights (ex: of 6 x 6) and the render time substantially decreased.

 

Additionally, running the Render Diagnostics reports that there are errors in my Area Lights as they are not uniformly sized and that artefacts will occur during render ... and sure enough, this occurs.  Sizing the Area Lights uniformly resolves the issue.

 

I've been attributing some of these anomalies to my lack of knowledge on the subtleties of Maya and/or Mental Ray; that said, I'm finding several significant gaps in the documentation which introduces a substantial amount of "guess work" as to the proper use of a feature.  

 

Of late, I have been using the Help Page Feedback feature as a vehicle to ask that clarification be provided as very few of the seasoned Autodesk folks seem to be able to make time available to respond in thread … it’s either that or I’m again, as I’m still new to Maya, I’m not asking the right questions.

___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

Message 13 of 18
remydrh
in reply to: Steve_Curley

I've not experienced that issue, what version of Maya are you using?

 

Are you using a light shader attached to the light? If so, which one?

 

And yes, the documentation is pretty atrocious when it comes to rendering. This is part of why we began Elementalray.

Message 14 of 18
hilaire.gagne
in reply to: remydrh

@remydrh:

 

I'm currently using Maya 2014 SP0, not the recent SP1 release ... trying to finish this lighting exercise before installing the updates.

 

As I'm looking to eventually pursue production (film) related work, I am deliberatly working with traditional lighting and shaders. 

 

Lighting & Shaders:

Shaders = all Maya (no MR) shaders in scene

Lights = all Maya (no MR) lights in scene, no GI, no Photons, etc.

 

 

I am using Mental Ray as the renderer in Pre-Unified Sampling  - i.e. using Legacy (Adaptive) rendering as many of the lighting exercise require transparency shadows and such.

 

I can generate the Render Diagnostic message by creating a new scene, adding a few geometry objects (sphere, cube, plane, etc.) and creating an Area Light.  Once created I scale the light such that it is not uniform in scale (ex: 6 x 10 x 2).  The Area Light MR feature is enable with a Sampling of 32 and a low sampling of 8 - alhtough this doesn't matter. I am using Linear Workflow, sRGB-in & sLinear-out.

 

For the next exercise scene, I plan to switch to using MR shaders and lights exclusively as I suspect that mixing and matching is ill-advised.  Had I known what I know now, I would have likely started using MR materials and lights at the beginning.

 

Cheers,

___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

Message 15 of 18
remydrh
in reply to: Steve_Curley

I have no idea why you're working in that way.

 

In film and feature animation, global illumination (be it final gather or path tracing) is now the norm. Anything else is how you would render in 2002. Everything has given way to raytracing, including the next major release of Renderman that relies on uni or bi-directional path tracing. (They were a bit behind) Do not use scanline, it's slow.

 

Maya common materials are deprecated. They are old and not energy conserving. Pretend they are not there. Forget them.

 

You should use mental ray and these materials: mia_material, car paint, sss2.  These materials will provide you with what you need until the layering library is more available. The mia_material will be your main material for most things.

 

Use area lights (of various shapes and sizes) for most everything when possbile. Physically based rendering relies on lights with area (shape).

 

Legacy Sampling and the Rasterizer are also deprecated. Unified Sampling will greatly improve your quality and speed for many (if not all) complex scenes. Motion blur and depth of field should not be rendered without using Unified Sampling.

 

Maya common materials translate to a mental ray equivalent at render time. This means they aren't necessarily difficult to mix and match, the problem is Maya common materials and lights were not designed with a physically based rendering system in mind. Achieving realistic or easily controlled images is much harder using those materials and lights.

 

Also, I see people using Mitchell filter a lot in here. Don't use that. It can lead to sharpening artifacts. Use gaussian 2.0 2.0 like the new default.

Message 16 of 18
remydrh
in reply to: remydrh

Message 17 of 18
hilaire.gagne
in reply to: remydrh

RE: I have no idea why you're working in that way.

 

I've been going through what has been available through various sources such as CG Society, Gnomon Workshop, Digital Tutors, MasterZAP, Floze, Jermery Birn, Jeremy Vickery, Jeremy Engleman, Lee Lanier ... to name but a few. 🙂

 

And most of the information advocated in their tutorials is to avoid GI, FG, etc. as it's too difficult to predict the result frame-to-frame.  And one should learn how to simulate those effects throught traditional methods.

 

If you have some additional resources (book, tutorial, sites, or otherwise) to recommend, I'd certainly be grateful to hear about them.  I suppose it's one of the challenges of starting out in this industry ... aka late to the party. 🙂

 

 

Re: In film and feature animation, global illumination (be it final gather or path tracing) is now the norm. Anything else is how you would render in 2002. Everything has given way to raytracing, including the next major release of Renderman that relies on uni or bi-directional path tracing. (They were a bit behind) Do not use scanline, it's slow.

 

I've spent some more time on the site you linked and from what I've read and understood, Unified Sampling most certainly seems the way to go.  I've committed to myself to complete my current lighting challenge using the traditional (restrictive) approach.  Once I'm done, my next one will be certainly be using the recommendation you've posted below.

 

 

RE: Maya common materials are deprecated. They are old and not energy conserving. Pretend they are not there. Forget them.

 

This is probably the most useful reponse I've run across in the past 12 months.  I often wondered if these materials where commonly used "these days" ... it's probably been noted by others and I'm going to assume that as newcomer, I hadn't connected the "dots".

 

 

Re: You should use mental ray and these materials: mia_material, car paint, sss2.  These materials will provide you with what you need until the layering library is more available. The mia_material will be your main material for most things.

 

How does that "fit in" with large production studios (Pixar, Dreamworks, etc.)?  For example, if I were to work on deliverables, do I need to convert my work product materials, etc. to something that will be usable in their pipeline before I submit. 

 

I get the format conversion (ex: OBJ, FBX, etc.) but what about materials (procedurals, mia_material, etc.)?   If I were to use MRay type materials, am I assuming that the end recipient will be able to convert my submitted work product to their format? 

 

I see many folks use tools such as Nuke, Arnold, VRay, and MRay seems to be falling out-of-favour.  I guess I wonder why Autodesk would still bundle MRay if it's that poor of a render [personally, I find it works well once you understand how it's intended to be used].  I can't commit the financial resouces at the moment to purchase Nuke, Arnold, etc. ... I spent all my resources dollars purchasing Autodesk Entertainment Creation Suite. 😉

 

 

RE: Use area lights (of various shapes and sizes) for most everything when possbile. Physically based rendering relies on lights with area (shape).

 

Again, another extremely useful post reply - thank you!  I've been struggling with which light to use and when for quite some time.  I'll say that it's forced me to become quite intimate with the pros/cons of each light type.

 

In my current lighting exercise, I've avoided using Area Lights, although I much prefer the result they provide, as I was concerned that most folks stay away from these as they seem to take longer during render. 

 

I'm still struggling however with why the Render Diagnostics reports my oddly sized Area Lights as being a problem.  I'm going to assume that's it's likely a cause of using non-Unified sampling at render time and that it won't be an issue once I switch over.

 

 

RE: Legacy Sampling and the Rasterizer are also deprecated. Unified Sampling will greatly improve your quality and speed for many (if not all) complex scenes. Motion blur and depth of field should not be rendered without using Unified Sampling.

 

From the information I digested so far at the site link you provided, I see the benefits to Unified Sampling.  🙂

 

 

RE: Maya common materials translate to a mental ray equivalent at render time. This means they aren't necessarily difficult to mix and match, the problem is Maya common materials and lights were not designed with a physically based rendering system in mind. Achieving realistic or easily controlled images is much harder using those materials and lights.

 

Good know ... that's something else that if mentioned in the documentation, isn't very clear or obvious enough for those starting out to catch on to.

 

 

RE: Also, I see people using Mitchell filter a lot in here. Don't use that. It can lead to sharpening artifacts. Use gaussian 2.0 2.0 like the new default.

 

I wish I had posted this questions about 12 months ago, when all I seemed to run into was how the Mitchell filter was the "way to go".  Even the Maya documentation recommends it as the choice filter.  I'll go back through those sections of the documentation and use the "report option" and flag an inquiry as to the accuracy of their text.

 

___________________________________________
DELL Precision T7500, Dual XEON Quad Core
48 GB RAM, 2x1TB SSD, nVidia GeForce 2080 Super
Windows 10 Pro (64-bit, 21H1), DirectX 12
Autodesk Entertainment Creation Suite 2022
___________________________________________

Message 18 of 18
remydrh
in reply to: hilaire.gagne

I think the resources you're looking at on the internet are probably outdated. The problem with a lot of information that's out there and easy to find is that it's old and no one has done any house cleaning.

 

GI is a standard in film. Old direct lighting techniques are gone. Now you light more like the real world. This should be more intuitive for you.

 

The Maya Common materials are easily available and any renderer can plug into them. That's part of why they are still on the front shelf for rendering. Also, the original Maya way to render in mental ray was designed to mimic the Maya Software way. . .in 2001. Things have changed and Autodesk is beginning (although late) to move that in a better direction.

 

Any deliverables you have should be in images. If you send scene data it's understood that a lot of things won't translate. Dreamworks uses their own renderer and shading engine. You cannot match their materials. Pixar, Sony, etc all use proprietary tools no one else would have access to. So it's not expected that you would deliver them scene data for any reason.

 

If you mean submitted work for a demo, then you only send images. Avoid sending scenes. textures, etc to anyone that ight use them for their own gain. . .

 

mental ray is not a poor renderer. In fact it's still the fastest raytracer for production rendering.

 

The problem is an old problem where Autodesk is/was in charge of integrating mental ray into Maya. And they haven't spent any time or energy on improving that integration in years. Only recently with 2014 has the relationship been renewed and Autodesk is serious about improving the experience. But they have some work to catch up on to make all of the features of mental ray available in Maya where it can be used easily and correctly. Arnold, Vray, etc do their own integration so they can push out features and changed immediately if they want without relying on Autodesk.

 

nVidia sells technology for integration. CUDA, GPUs, Tegra, mental ray, etc are all products for other companies to take and integrate. Asus makes GeForce cards and Tegra tablets, MSI makes GeForce, etc. Typically they get that technology from nVidia. Autodesk integrates mental ray instread of their own renderer.

 

I need to check on the non-uniform problem, not seeing that error myself.

 

People like the mitchell filter becuase it's sharp. But because of the shape of the filter it can introduce artifacts, especially around highlights and reflections. Using Gaussian 2.0 2.0 is pretty standard for most renderers and looks sharp without artifacts.

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