Does anybody here know some free redering tutorials with a somewhat recent version of Houdini?
All the renders, I can come up with intuitively, are either awefully grainy or take way too long. I would like to know more about basic rendering with Mantra especially in regards of indirect light/ global illumination/ final gathering, I don't know what term to use since I've already heard about all of them in Mantra so far but once again the naming seems a little strange to me.
So far I don't like Mantra and the entire rendering workflow at all but I would like know more about it. Unfortunatelly the tutorials I can find are all made with relatively old versions, considering that many changes were made throughout the last versions these tutorials are not really helpful.

Which naming bits are the worst offenders?

Noise is simply called variance, which means being different, so the controls are made to make the image ‘less different’

The mantra masterclass is a good place to start:
http://www.sidefx.com/index.php?option=com_content&task=view&id=2160&Itemid=344 [sidefx.com]

MartybNz
Which naming bits are the worst offenders?

I can't even tell because I'm still too confused.

The masterclass unfortunatelly doesn't help me. He is showing some fancy features which I'm hardly interested in. All I want as a start is clearity and simple basic workflows that give me good results.

1. There are a few render engines just within Mantra alone (raytracing, micropolygon rendering, pbr, micropolygon pbr, photon map generation) and no one explains clearly what is used for what, how to use them, where do the engines differ and so on and so forth.
What I see is a tutor that quite naturally jumps between the engines back and forth and I don't understand single thing what he is doing.

2. I need a clear introduction in how to use the different render engines with indirect light. I don't know what indirect lighting model is used in Mantra. Is it global illumination, final gathering, in Maya there's also something like irradiance particles but I haven't found one tutorial so far explaining this at least with on sentence.

3. Now, when I know about the indirect lighting method(s) that is/are used in Mantra, now someone can explain me step by step how they work, where to tweak the settings and how to twaek them to optimize render quality in relation to render time.
Tutorials I've seen, the tutor kicks of one ipr after the other without actually explaining what he is doing and before I'm able to grasp what he/she actually wanted to show me he/she is already 5 steps further.

So far I was thinking that I was doing something wrong, getting no render with reasonable quality. But more and more I think it's not only me…

Micro-polygon and raytracing are very well known render engines.

If you search for REYES, render everything you ever see, you'll learn about micropolygon

Raytracing too.

There is a good page here.
http://www.sidefx.com/docs/houdini13.0/render/understanding [sidefx.com]

Think of a render engine is ‘simply’ is a big averaging machine.

Hello clown
start here:
http://www.sidefx.com/index.php?option=com_content&task=blogcategory&id=202&Itemid=361 [sidefx.com]
(lesson 6 is about attributes, lesson 7 is about rendering etc..)

Another introduction tutorial is there:
http://www.digitaltutors.com/tutorial/3557-Introduction-to-Mantra-in-Houdini [digitaltutors.com]

Then continue over there for more in depth training:
http://www.sidefx.com/index.php?option=com_content&task=blogcategory&id=203&Itemid=362 [sidefx.com]

And also there:
https://cmivfx.com/store/203-houdini+shading+and+rendering [cmivfx.com]

And don't forget about manual.

There are also couple of very good tutorials on vimeo and some on youtube. Most of them are listed there http://www.sidefx.com/index.php?option=com_content&task=blogsection&id=14&Itemid=132 [sidefx.com]

Ok, all the time I was thinking, I was doing something wrong but now that I've watched the tutorials you have linked here, some of them I already knew, I can now officially say that Mantra is a pretty bad renderer. Very sad.

Do you mean the renderer or your understanding of rendering?

I've rendered some quite complex scenes mith mental ray, dealing with a lot of optimizing fg settings, baking fg maps, optimizing BSP acceleration, baked lighting where possible and all this stuff, everything in relation to rendertime, so I would say my understanding of rendering is quite ok.
But Mantra is renderer that basically only has two controls for quality, pixel sample and noise. As I said, at first I thought that I was missing something but the documentation and the videos confirm my concerns. There are only these two settings and due to the noisyness of the PBR you have to crank these values up to get a reasonable result which then, of course, takes way too long. And appart from that the quality is resolution dependent in regards of noisyness and sorry, that's totally inaccaptable. There are so many things i dislike about Mantra, I don't even know where to start. All in all, this is not what I call a powerful renderer.

Ah, thanks a lot for that profound conclusion, looking back in time I wonder why I had so much joy….

or maybe Your first thought was right

Korny Klown2
Ok, all the time I was thinking, I was doing something wrong but now that I've watched the tutorials you have linked here, some of them I already knew, I can now officially say that Mantra is a pretty bad renderer. Very sad.

How do you rate other renders like Arnold and renderman renderers? Perhaps for your projects it isn't the correct tool but Mantra is considered to be equal to these renderers for A grade VFX work.

MartybNz
Perhaps for your projects it isn't the correct tool but Mantra is considered to be equal to these renderers for A grade VFX work.

How far is my work different then the work of others? Renderquality in relation to rendertimes is always an issue, isn't it?
I don't know about Arnold and Renderman, haven't used them so far, I'm just familiar with Mental Ray and V-Ray. Maybe I'm just stunned to see a renderer that works so extremely different then the usual suspects. what exactly are the needs of A grade VFX, because I yet can't imagine a situation where I would find Mantra powerful. What exacly does Mantra offer that only A grade VFX do benefit from?
Maybe the Mental Ray renderer that comes with Houdini thrills me a bit more but unfortunatelly I can't test it in the apprentice version. Are there people using Mental Ray in Houdini seriously or is that just a funny gimmick?

What you're experiencing is rendering ‘culture shock’; every mr users gets this

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=21548&highlight=&sid=89dbd74eca95a75219957715f93c79ad [sidefx.com]

http://forums.odforce.net/topic/6015-gi-in-mental-ray/ [forums.odforce.net]

Reading FxGuide on rendering MR users love controls.

https://www.fxguide.com/featured/the-state-of-rendering-part-2/#mentalray [fxguide.com]

Edit: there's a great link in there:

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=11436&start=0&postdays=0&postorder=asc&highlight= [sidefx.com]

Hi Korny Klown2,

since you asked, here are some answers:

Korny Klown2
How far is my work different then the work of others? Renderquality in relation to rendertimes is always an issue, isn't it?

What work would that be, print/design, animation, VFX?
It all depends, spending time to optimize render times and in Mental Rays case rendering at all, can actually lead to more artist time than simply setting the samples (noise levels) and render away.

Korny Klown2
I don't know about Arnold and Renderman, haven't used them so far, I'm just familiar with Mental Ray and V-Ray. Maybe I'm just stunned to see a renderer that works so extremely different then the usual suspects.

Usual suspects :-) So, I will not say anything bad about V-Ray, but I will certainly not say anything good about Mental Ray as a production renderer for VFX/Animation work. With a solid understanding of how render engines work, looking at the mantra options one should be able to identify common ground.

Korny Klown2
Are there people using Mental Ray in Houdini seriously or is that just a funny gimmick?

I don't know anyone who has used Mental Ray in the past 4-5 years for anything seriously and not bitched about it. And by that I refer to VFX/Animation.

Thanks Andy58.

Kk2 - Do you always have to shout - “Houdini sucks”, then learn that it has a different approach? Your experience with AD centered products is a part of the 3d world, which provides you with experience but not knowledge.

The world outside that cocoon is much more interesting.

MartybNz
What you're experiencing is rendering ‘culture shock’; every mr users gets this

Indeed, but how to get out of this shock?

MartybNz
…MR users love controls.

Oh yes, we do and we are lost without them.

Lucas Martell
Because we already know those settings inside and out, we’ve never run into something that we couldn’t do in MR.

Andy58
It all depends, spending time to optimize render times and in Mental Rays case rendering at all, can actually lead to more artist time than simply setting the samples (noise levels) and render away.

I recently had a project with a VFX sequence shot (over 4000 frames) spending the time to optimize your rendertime will definitely pay out.

Andy58
What work would that be, print/design, animation, VFX?

Since I'm mostly working as a VFX generalist probably for everything


Although I understand that atikin attitude is a bit rough, I also get his point and have to solidarize with some of his statements.

atikin
Just to render test scenes with spheres in 1 hour? I mean, when you model something, I guess a test render with no textures shouldn't take SOOOOOO much time and give a crapy result…

atikin

el_diablo
You need to play with it more…

Works pretty nice once you get used to it. I did direct compare with mental ray on a cell phone animation and Mantra was just as fast, but also did rendertime SDS, and the motion blured version wasnt much slower.

Hmmm… how can I get used to something, if I don't even know where to start?

It's hard to find out how to get better results with Mantra, in a reasonable time, when even the help says

help
There are two main controls on the mantra node for decreasing noise in PBR renders. Pixel samples and Noise level

I then tried to change these values but it didn't got better. So what to do now, when even the help can't tell you any more? Maybe Mantra has supernatural capabilities, maybe the secret is just to say “Mantra” three times into mirror but so far I don't know what to do furthermore, because the only thing I'm capable to produce is a testscene with two untextured objects, that takes 5 minutes or so and still is noisy.
If anyone has a secret key, please tell me about it.

Korny Klown2
I then tried to change these values but it didn't got better. So what to do now, when even the help can't tell you any more? Maybe Mantra has supernatural capabilities, maybe the secret is just to say “Mantra” three times into mirror but so far I don't know what to do furthermore, because the only thing I'm capable to produce is a testscene with two untextured objects, that takes 5 minutes or so and still is noisy.
If anyone has a secret key, please tell me about it.

The first question is what creates the noise? Hint - it's based on gambling

MartybNz
Thanks Andy58.

Kk2 - Do you always have to shout - “Houdini sucks”, then learn that it has a different approach? Your experience with AD centered products is a part of the 3d world, which provides you with experience but not knowledge.

The world outside that cocoon is much more interesting.

Well, I don't like the mentality that everything around Houdini is heaven-sent. Yes, Houdini is based on very good idea but that is no reason to be condescending. Houdini still is unnecessarily complicated designed and far away from being perfect. Remember the conflict between binary programmers and soap programmers, how large this cocoon is depends on how openminded we are.

MartybNz
The first question is what creates the noise? Hint - it's based on gambling

What I know so far, it's because of the stochastic nature of PBR.

Korny Klown2
Well, I don't like the mentality that everything around Houdini is heaven-sent. .

No one is saying that but yourself. You are fighting yourself

Korny Klown2
What I know so far, it's because of the stochastic nature of PBR.

That's pretty much straight from the manual. Explain what you think it means and how it applies to rays.

MartybNz

Korny Klown2
Well, I don't like the mentality that everything around Houdini is heaven-sent. .

No one is saying that but yourself. You are fighting yourself

Oh no, I'm not saying this at all. It's more a feeling, the vibrations I recieve from the community, something you can clearly read between the lines that Houdini gets glorified from many users. There is this vibe of “I was blind (I used some other 3D app) but now I can see (now I'm using Houdini).”

MartybNz
That's pretty much straight from the manual. Explain what you think it means and how it applies to rays.

Stochastic has to do with probability, so what I know from current research, I would summarize as: Rays get randomly sent out from the camera, they hit the surface somewhere and deliver a value, let's say a color value. It will then compare this value with the surrounding values to find a “correct answer” for the final color of this one pixel. It will compare the values as often as the min and max ray samples are set. So for min 1 and max 9 it will compare the values at least once or up to 9 times if it doesn't find a “correct answer” for that pixel.