Gyroscope
@circusmonkey
6) I love that suggestion circusmonkey! I was working on the latest CGTalk lighting challenge [forums.cgsociety.org] but got majorly sidelined by work. I've got the scene but no shaders set up.

If that scene isn't fully shared, maybe I can set up this older CG Lighting Challenge [3drender.com] that can be used.

7) Was that 3 hours at 2k? Arzo's dual xeon with 72gb of ram.. I can only imagine dual 3.0ghz 8 cores at a total of 32 threads. And yeah 30 minutes a frame on that machine seems like a lot.

I certainly think it would be useful, It would be nice if we had sub forums here , lighting render / DOP's etc . Ive ripped into the boxes scene and already I have improved things by using alembic and doing some extensive scene management. Some of the shaders are not exactly helping either like the floor and box shaders for example which is using an old vex plastic shader . The floor shader has a diffuse intensity of 0.2 which is saying the material has a very low diffuse reflectivity near to metal like gold or chrome which I set at 0.15




Rob

Hehe fun, I tried as well, 5 diffuse bounces and some heavy DoF.
1m30s for straight PBR. 25s with GI.

Skybar
Hehe fun, I tried as well, 5 diffuse bounces and some heavy DoF.
1m30s for straight PBR. 25s with GI.

Any chance for the scene? I'm being contradictory in my last posts towards KK2 as I too want to learn how to optimize Mantra. Sorry mate.

Edit: And it'd be nice to post system specs when posting times.

Gyroscope

Skybar
Hehe fun, I tried as well, 5 diffuse bounces and some heavy DoF.
1m30s for straight PBR. 25s with GI.

Any chance for the scene? I'm being contradictory in my last posts towards KK2 as I too want to learn how to optimize Mantra. Sorry mate.

Edit: And it'd be nice to post system specs when posting times.

Ah I didn't save, just did some quick testing. But between 7-9 pixel simples, and 2-32 ray samples with 0.016 noise level. It's all about tweaking really, getting the “right” noise level can be great. If you set it too low it will probably use your max ray samples everywhere, but if you find the sweetspot it will be more adaptive. Atleast thats how I understand it, I'm not really a renderguy I just tweak stuff until noise/time-ratio is acceptable to me :p

I'm on a six-core i7, so might be a bit faster than your quad.

Skybar
Ah I didn't save, just did some quick testing. But between 7-9 pixel simples, and 2-32 ray samples with 0.016 noise level. It's all about tweaking really, getting the “right” noise level can be great. If you set it too low it will probably use your max ray samples everywhere, but if you find the sweetspot it will be more adaptive. Atleast thats how I understand it, I'm not really a renderguy I just tweak stuff until noise/time-ratio is acceptable to me :p

I'd be very interessted as well, so if you like to “tweak stuff until noise/time-ratio is acceptable” again I appreciate if you save and upload these settings.

1) Write all your geometry to disk, right now your scene cooks all your poly modelling. Thats one big no no .

2) Explore instancing and packed primitives

its fun i just realized i was doing this wrong too the whole time. didnt realize how fast alembic and packed prims are.

my mantra seems on speed now

4) Is your ray tracing bias set correctly for your scene size ? Put a bound over the scene ie 70000 unit scene size x 0.01 .

is it possible you could explain this in more detail? i never played with this parameter and i dont fully understand what you mean by x 0.01?

5 Why have you set 2 diffuse bounces on the mantra ROP and set min ray samples to 5 ? with pixel samples 7 x 7 with PBR. What was your thinking ?

could you explain what is wrong with this? sorry i'm really new to all this. i was playing with these parameters too but takes time to realize what you're actually doing.

thanks in advance!

I would also love to see a subforum here for rendering since as a newbie its hard to find good examples and discussion about the topic.

Gyroscope
Here's a modified scene. 35 seconds to render on my machine. Mimics your non-reflective Maya render as was discussed earlier but seems to be ignored?

Well, that's a decent start but still noisy and
1. the same scene takes twice as long on my machine 00:48
2. when I tweak it to get it noisefree I immediately run into rendertimes of 3minutes and more.

Gyroscope
I can't tell what you really want to know. You seem to know what you need to know but aren't wanting to accept it? It is actually that simplified when it's a noise problem.

I want a cristal clear image in a decent amount of time and I want control over where I want quality to be focused and where I want to reduce quality.

Gyroscope
I can't think of a modern rendering engine that is not using this approach. And I'm thankful as I don't have to spend hours dialing in numbers and spend more time on the art.

The problem is, I don't care about a modern renderer because my clients don't care. If I'd work at ILM or DD or so I would probably like Mantra because I get high quality and don't have to care about rendertime. But my clients more often than not wouldn't see the extra quality, all they see on the bill is that it took two days longer to render.

By the way, why isn't Mental Ray available in the apprentice version? To make Mantra available for free and Mental Ray not somehow creates the feeling that Mental Ray is something special which you only get when you buy Houdini, whereas Mantra is just some ordinary renderer.

Korny Klown2
I'd be very interessted as well, so if you like to “tweak stuff until noise/time-ratio is acceptable” again I appreciate if you save and upload these settings.

I'll see if I find the time to do it later.

Korny Klown2
By the way, why isn't Mental Ray available in the apprentice version? To make Mantra available for free and Mental Ray not somehow creates the feeling that Mental Ray is something special which you only get when you buy Houdini, whereas Mantra is just some ordinary renderer.

Mantra is created by SideFX, so is Houdini. Mental Ray however is created by another company, why would you expect that to be included in Houdini? That makes as much sense as if Maya would come with Mantra.

Actually Houdini comes with Mental Ray 3.6, you can check that in the Prefs under Rendering. I can drop down a mentalray ROP but when I want to render it it says: Error: Outputdriver is not supported in Apprentice version.
So I wonder why it comes natively with Mental Ray but you can't use it in the apprentce version.

Korny Klown2
So I wonder why it comes natively with Mental Ray but you can't use it in the apprentce version.

To be unambiguous, it doesn't come with Mental Ray the renderer, but with a capability/plugin/bridge/exporter to render with Mental Ray.

My guess for the reason is that SideFX can't force Mental Ray to render a watermark, and thus an apprentice licence could be used to render commercial work.

Korny Klown2
Well, that's a decent start but still noisy and
1. the same scene takes twice as long on my machine 00:48
2. when I tweak it to get it noisefree I immediately run into rendertimes of 3minutes and more.

Your machine is pretty weak. I personally think that the noise is acceptable. I don't know many clients who want to pay for a Cornell Box render.

Some of that noise would be less visible in a production scene where you have textures, different environment and more artistic lighting. I've no problems getting acceptable renders using the methods discussed. It could be faster I agree, which is why I want to make a better scene to test it out. Cornell Box test is to test the contributions of GI. Your MR render doesn't look accurate.

If your clients are pushing for higher quality, you should be charging more to get them the results which includes the cost of rendering. Your Maya render is pretty ugly IMO. I don't know what your acceptable noise tolerance is but, can you post a render of your 3 minute frame? You said you would have to add AO to your MR render, and I agree. How long does that take for you to add a seperate AO render pass? The Mantra render doesn't need it in my opinion.

Korny Klown2
I want a cristal clear image in a decent amount of time and I want control over where I want quality to be focused and where I want to reduce quality.

Try turning off GI if you want/have to render with Mantra then. If machine time is not cheaper for you than artist time. The noise will then come from the Light Sampling quality. Go to town setting up hundreds of lights to mimic the effect of GI. Total control.

The methods discussed, I find have been interchangeable with Mental Ray Unified Sampling, Vray, Arnold, Maxwell, any GPU render. If that's still not to your liking then move on. I love the accuracy, ease and photographic nature of Maxwell, but F**CK does it take forever to render. So I rarely use it unless the situation calls for it. Tools for the job.

Korny Klown2
The problem is, I don't care about a modern renderer because my clients don't care. If I'd work at ILM or DD or so I would probably like Mantra because I get high quality and don't have to care about rendertime. But my clients more often than not wouldn't see the extra quality, all they see on the bill is that it took two days longer to render.

I don't work at ILM or DD, I work in a small shop where sometimes I have to do everything and I like Mantra. Like I said it could be faster but we're at a point where I feel we matched your poor non-AO MR render with a better more accurate (and possibly faster, until you add AO) Mantra render.

The next step is for you to add DOF, Motion Blur and Animation to your test. We can compare set up time and render times then. If single image print is your end goal. I have to agree Mental Ray works wonderfully. Vray better… But you said you do VFX generalist stuff. Maybe if we focus on getting one of your water sims or flame sims optimized that'd be a better case. Cornell Box would be more Arch/Product Viz territory.

Overall, you like Mental Ray it's what you're used to which is understandable. Seems like you have not adopted the unified sampling method Mentral Ray now offers though. If you want to stick with MR, do it.

Use Houdini as a pipeline tool. It's been tailored to send data back to Maya for finalizing. If speed is your concern on a budget, look into GPU rendering. There are coveats there but my gosh it's so worth it when you can use it.

Gyroscope
Your machine is pretty weak.

Maybe Houdini/Mantra doesn't like AMD and prefers Intel but I have a 4C8T processor with 3.5 GHz and 12 GB RAM, so technically it shouldn't be that bad.

Gyroscope
You said you would have to add AO to your MR render, and I agree. How long does that take for you to add a seperate AO render pass?

Luckily with Mental Ray it's just the matter of activating AO in the materials and one checkbox in the renderglobals. With AO the rendering took 3 seconds longer.

Gyroscope
I don't work at ILM or DD, I work in a small shop where sometimes I have to do everything and I like Mantra. Like I said it could be faster but we're at a point where I feel we matched your poor non-AO MR render with a better more accurate (and possibly faster, until you add AO) Mantra render.

Why does everybody beef about my Mental Ray rendering. I never said that this is the holy grail of photorealistic CG and it's not the quality of my wet dreams either but it is a reasonable good quality in a reasonable amount of time. Clients I know, I could show them MR rendering and Mantra rendering side by side, they wouldn't even notice the difference so why should I spend more time rendering for a higher quality, only a few clients would appreciate.

Gyroscope
The next step is for you to add DOF, Motion Blur and Animation to your test. We can compare set up time and render times then. If single image print is your end goal. I have to agree Mental Ray works wonderfully.

DOF, motion blur and stuff is all done in post (as well as GRAIN by the way, that's why I want a cristal clear/ noisefree image because adding noise on noise is a nono)

My summary is:
Mantra is a renderer that indeed gives you great results but so far it doesn't fit my needs. I don't know if sending data back and forth is what I want because some things don't work this way. First of all it would destroy the concept of procedualism and I don't know if exchanging fluid sims is possible anyway espacially with foam and spray.

To be unambiguous, it doesn't come with Mental Ray the renderer, but with a capability/plugin/bridge/exporter to render with Mental Ray.

Where would I get this plugin? Is there something like a MR for Houdini build or do I need the standalone from AD?

Korny Klown2
that is in fact arrogant.

Lol, this matches your first postings on SideFX "..sounds pretty arrogant and impudent. "

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=30366&postdays=0&postorder=asc&start=25 [sidefx.com]

In two decades of working in vfx I've never met anyone who doesn't infer, but, you're in good hands here as others are helping here. Cheers.

Korny Klown2
Why does everybody beef about my Mental Ray rendering…

It's not about you rendering with Mental Ray, don't take it personally.
It's all about Mental Ray and the pain it has inflicted to us who were forced to use it as a production renderer.

It's not your fault :-)

Andy

P.S.: Seems like I got beaten by the time zone in further helping you learn about mantra.

Korny Klown2
DOF, motion blur and stuff is all done in post (as well as GRAIN by the way, that's why I want a cristal clear/ noisefree image because adding noise on noise is a nono)

You care about noise alot, don't you? I wonder how that noise holds up in todays world of broadcast MPEG2 and online H.264? Or does your work go to digital projectors only?

Andy

Korny Klown2
Maybe Houdini/Mantra doesn't like AMD and prefers Intel but I have a 4C8T processor with 3.5 GHz and 12 GB RAM, so technically it shouldn't be that bad.

I don't think Mantra uses any specific Intel instruction set such as Embree. AMD this gen has not really been able to compete with Intel for performance. [anandtech.com] Core count is only one half of the equation. IPC is the other.

Korny Klown2
Luckily with Mental Ray it's just the matter of activating AO in the materials and one checkbox in the renderglobals. With AO the rendering took 3 seconds longer.

Can we see? Where's your 3 minute noise-free mantra render and scene?

Korny Klown2
Why does everybody beef about my Mental Ray rendering. I never said that this is the holy grail of photorealistic CG and it's not the quality of my wet dreams either but it is a reasonable good quality in a reasonable amount of time. Clients I know, I could show them MR rendering and Mantra rendering side by side, they wouldn't even notice the difference so why should I spend more time rendering for a higher quality, only a few clients would appreciate.

Then what metric are we supposed to base your conclusions off of? I'm only going off of what is presented. And your case has become increasingly weak.

Korny Klown2
DOF, motion blur and stuff is all done in post (as well as GRAIN by the way, that's why I want a cristal clear/ noisefree image because adding noise on noise is a nono).

That post work done requires multple passes, plug-ins, external editors, layered renders, compositing time, re-rendering of sequence time. Only for it to look remotely natural. This extends to the argument of Artist Time vs Machine Time.

You may not like a bit of noise in your renders, which you still have not posted for us to disect and help you. I hate the look of post motion blur and DOF.

As a generalist who doesn't have a whole compositing department, it's something I'm glad I don't have to spend time/money on. With the advent of modern rendering methods, you can get servicable motion blur and DOF straight out, which yes, takes a small hit in rendering time. But I firmly believe in the artist time is more expensive than machine time mantra.

Gyroscope
Can we see? Where's your 3 minute noise-free mantra render and scene?

No, I will definatelly not take the time to upload the AO version just to hear over and over again how much you guys don't like Mental Ray and its look, I got the message and I respect that.
There is no 3 minutes noisefree rendering

Gyroscope
That post work done requires multple passes, plug-ins, external editors, layered renders, compositing time, re-rendering of sequence time. Only for it to look remotely natural. This extends to the argument of Artist Time vs Machine Time. You may not like a bit of noise in your renders, which you still have not posted for us to disect and help you. I hate the look of post motion blur and DOF.

Agreed, for a short sequence or a still this probably doesn't pay off but for longer shots it is IMO beneficial to have full controll in post. You rendered 1500 frames, show it to the director and he says “…oh, that DOF is very heavy, can we make less?” “Sure, just let me render these 1500 frames again on my single machine.” This was not to be overly sarcastic but to show that there is a reason for this technologie to exist. And many companies make good use of it, so maybe for your personal taste it doesn't look but it's not THAT bad either.

That's disappointing. Not showing what you think is acceptable noise. Makes me question whether you're actually putting in an effort at this point. Despite me saying Mental Ray is great for some things. Just as Mantra is. I still use Mental Ray from time to time. It's just not my first choice, but hey it's “free” right?

If you're committed to this method of rendering, and you're tasked with rendering 1500 frames only for the director to say the DOF is excessive after the fact, the problem isn't in the rendering, it's in the approval process of your workflow. Render every 10/nth frame, cycle through that to make sure. Or something. Work smarter not harder.

This is even more fucking critical when you're a small shop.

If your director/supervisor doesn't like that, educate him/her. But yes, I do agree the post method has it's place I never said it was bad, I just hate having to do it and hate the look because I know it's wrong.

Good luck. Have fun.

Ok, I don't wanna be a poor sport so I put this side by side comparison together. To be quite honest, seeing this now side by side and maybe that's just my personal taste but there some aspects about the MR rendering I like more. For example, the edges of the room in Mantra rendering look a bit washed out. Maybe that can be fixed but it looks somewhat strange.

Box wasn't faceted so that's why the corners are washed out. Goof on both our ends for not catching that sooner. Basically a 4 sided sphere at that point, haha.

Comparing the difference of your 3:39 render and my 35s render did show some obvious noise difference, ignoring the jpg artifacts.

To match both mathematically and visually at 100% magnification. I dropped the noise 0.1. That's it. The render which is pretty damn close to yours only took 55s to render on my machine. Can you post the scene for your 3 minute render? You might've over cranked something. 35s to 48s to render is hardly double (which would be 1m10s).

Fixing the faceting problem actually reduced the render time to 40 seconds. So with that fix you have some time to spare if that noise is still not acceptable. You really only have to creep the values little by little.

It's optimizing stuff like this (and the double sided light, reflective properties, GI Light) which can lead to long render times, which is stuff I'm after. Looking forward to more guru level (circusmonkey, others) tips regarding this.

How long does it take your machine to calculate Final Gather? Generating Scene and calculating the GI Light only takes about a second in this scene in Mantra.

If I were to critique your MR render… The sphere is floating, the roof looks like there is a small separation between the walls with the harsh black outline. And it's not really a 100% exact scene with Houdini as the light is not in the same position. I know MR has trouble clamping values by default and the AA will add a few seconds with the light there.

Either way, going from an initial grainy 2m34s render to a clean 50s render sounds thread justifiable for me. I'll just speak for myself but I definitely learned stuff.