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Animated Spot starring Mantra

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Amazing shading, lighting... everything :) Cheerful look without colors being oversaturated - that's cool too.

Edited by OskarSwierad

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Hey all, small update here as I gear up for new upcoming spots in this series...and I'm sad to report that I've been working on moving all rendering into HtoA instead of Mantra. I find the look to be slightly nicer, the hair and fur shading to be a definite upgrade. Most importantly the render times are often an order of magnitude faster. I don't know what the guys at Solid Angle are doing, but I was pretty stunned to be honest. I expected Arnold to be faster, but I was thinking along the lines of a 25 or maybe even 50% speedup.

Only shame is losing all ability to render delayed load Alembic files, as well as losing some other nice Mantra stuff like PCopen in shaders, but that's very edge case stuff that I rarely if ever use.

Here's a look at Dad, Mom, Lisa, and Max all in their new Arnold lookdev.



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Nice render!

Just be careful about Arnold :) If you are interested in personal insight of not really convinced HtoA user, read further.

Performance wise, on test scenes Arnold seems to do better. For the real stuff I have to say this is often not true. You may be really faster at some cases for sure. I was impressed by the speed of volume rendering for instance. Fur is pretty good too. When you are dealing with some more difficult sampling situations though, you may have better performance and less headache with mantra for the final quality renders as Mantra provides more optimization controls. With arnold, I frequently end up bruteforcing the render as there are no other tools to get clean renders than sample more (that obviously can lead to very long render times even for relatively simple scenes). Memory management is truly great though.

On the user side, you will find many limitations. Things like light linking, instancing workflows, packed primitives, polysoups, mantra specific SHOP features, render masks, all these things are either not supported or are supported only partially. Sometimes it can turn a simple task into very dirty or annoying workaround.

Lighting tools are not even close to the Mantra's features and I find lighting workflows in general much more user friendly and better done in Mantra! Arnold lights don't support shape falloffs (so you will always get super sharp light source). You can use the texture for falloff but that's annoying and doesn't work for distant lights. So I usually end up painting distant light shape in nuke and then mapping it on the environment light (very awkward). Mesh lights are hell to get work. Physical sky model is just weird and badly implemented. I don't use it at all. Painting all environments in nuke or rendering out enviro maps with Mantra. You can't render visible lights (no!). Lights don't refract (nooo! why??). No custom distance falloffs. You can't see environment light in the viewport so setting up its direction is not a great user experience. Instancing lights not possible (or couldn't make it work).

What you can do in SHOPs is very basic. You will do better with Al shaders that provide some handy nodes but still it is nowhere close to mantra. 

Render with progressive option on is not very reliable. Sometimes what you see is not what you get. Arnold is keeping caches that's hard to make go away sometimes. No mousetracking in preview mode - no, seriously, this is the thing that you can not only play with for hours but also an awesome speedup tool for lighters! :)

On the other hand, I also really like some things about Arnold! :) Al Shader model is very good. Standard model is fine too but lacks some features (local oversampling for instance). All the GI math seems to work a bit better than in Mantra. Much better memory management. Straightforward Rayswitch SHOP. Render visibility options on object level and lights contribution options are better. Render diagnostics and verbose output are better. Very fast volume and fur rendering. Automatic tx conversion. For artists that are primarily not lighters or are juniors, Arnold is much easier to pick up.

Sorry for the text being too long :)

Cheers and good luck!


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Thanks for the post, agree with much of it for sure aside from the first paragraph! All of my testing with Arnold so far has been in existing scenes with identical light rigs to the ones used in Mantra, and it's just absolutely blowing it away on speed while actually delivering better looking images with much better sampling.

Our Mantra renders were all done with 6x6 pixel samples, with either 9/12/18 variance samples using a 0.008 threshold...so really quite tame render settings by Mantra's standards. The lighting was about as simple as I could possibly make it, to the point where we weren't rendering anything in the scenes except for the characters, with spherical HDRIs rendered from our digital set using a camera placed where the character is. Even with all of that optimization, HD character frames (single character, not even the family) were still taking nearly an hour on my 36 core render machines. Arnold with that same setup and 12x12 pixel samples is only taking 3-4 minutes. I've got 4 of those 36 core machines, and even all working together on a single character pass I generally won't even get 2 seconds of animation rendered overnight. Arnold is turning around 5 second long turntables of the entire family in under 5 hours.

Instancing is definitely a pain in the ass with Arnold, I dearly miss my packed Copy SOP workflows. Object control in general is a bit of a pain in the ass too as shaders aren't able to toggle the key Arnold switches like "opaque" "self shadow" etc. So now if I have let's say a character I want to render, I need all SSS skin related geo in an /obj/ node called "SKIN" with the SSS set named after that character. Then I need an /obj/ node for "EYES" with that same SSS set, but with opaque turned off so that the sclera can refract. Then I need another /obj/ node for "EXTRAS" with all of the character's clothing and props in it, with no SSS set enabled...otherwise the SSS calc looks wrong. Then I need another node for the hair. One more for the peach fuzz with opaque turned off.

Messy for sure, but very happy to trade the cleaner Mantra organization in exchange for Arnold's huge speed increase and improved look.

The SHOPs are definitely basic. I've got Anders' shading package which is amazing, but I had to make my own Schlick falloff node and a whole bunch of other stuff.

The Environment Light thing is also pretty annoying, but I made my own Arnold Environment HDA that lets me see a perfect viewport representation and be able to render the HDRI as a render background as well. I haven't really put it through its paces yet and I'm sure there's lots of issues I haven't thought of, but I'll post it here if you or anyone wants to pick it up. Lemme know if you add anything cool to it and maybe send it back my way too! Been meaning to do the same for Arnold rect lights so you can preview them better too.

Regarding light falloff, I hugely prefer Arnold to Mantra on this one because I don't know if you've ever tested Mantra's grid lights with actual HDRI textures plugged in...but the sampling goes to hell and basically means you can't really do production renders with anything but the default perfectly illuminated squares. 90% of the time this is fine, but when you're doing sharp reflective stuff you really want to have those nice softbox/kino/spot dish HDRIs plugged into your lights.

I still haven't tried to render actual volumes with Arnold yet aside from just their environment fog type things. Can you feed in live Houdini VDB nodes and have them render, or do you always have to write out a .VDB file and render that?

Cheers, and I may PM you to pick your brain on Arnold stuff in the future if you don't mind! I feel like I'm in pretty good shape after reading the docs literally cover to cover once or four times, along with all of Anders' literature, but I'm sure there's tons I'm missing.




Edited by Kardonn
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Here's a better look at the dog's fur. Really happy with how fluffy and soft it looks, always such a struggle to get that look for hair compared to the more wet and shiny look.


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Well, what can I say other that we have different opinions on Mantra's speed :) I dunno, maybe it is diffrent kind of stuff we are rendering or different workflows we are used to but I really don't consider Arnold as an ultimately fast renderer and Mantra as a slow one. Both have their advantages for sure. I actually have swapped to mantra from arnold a few times (or even to Mental Ray once) to render a specific shots on a show because I was not able to make render times reasonable with Arnold. Other times I wished to be able to render something in Arnold because I knew it would perform better for that specific task. In general I think Mantra is more mature and solid renderer though. I mean, this has always been Arnold's tradeoff - they made it straightforward for us and it is really hard to se it up completely wrong, however, we have fewer handy sliders to play with that are missing badly sometimes. It only depends what is the nature of the job you are doing and what is the nature of the artist making it happen :)

Regarding to HDR textured lights, I use them a lot in Mantra and find them better than in Arnold (from ease of use point of view). Can't really explain this opinion discrepancy on that :) Sure, it gets noisy but that is true for both renderers. Textured area lights are allways expensive. Btw. I find Mantra's shape fallofs that make no addition to render times or noise really a great feature because that is something I'm using so frequently and in other renderers I always had to use a texture.

As for rendering volumes, never tried to render live VDB. I tend to always cache everything first to make renders faster. I was rendering some clouds with displacements and the speed of that was just great.

And for sure we can share the knowledge so don't hesitate to PM me. I will do the same :)

Cheers and thanks for HDAs!


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