Shader lirary

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I have the same convesation with the guys from SESI a couple of weeks ago, I am sure you too jordi, and I think is an area where customers and users needs to ask to Side FX for solutions/improvements.
Thanks to the improvements and maturity of Mantra it is becoming a more accepted solution in many studios, more and more lighters are beggining to use it and this arise the problem of usability and solutions tailored for this part of the production.
Not lighting for FX but for the whole lighting department which is a different thing.
Many improvement are coming in this area with H13 but we got the point where the VEX architecture has it limitations.
VEX is a beatiful solution, one language and context to modify them all.
But well, for look development you need something different.
I love Lightwave approach, the concept of surfaces as uber shaders assigned to your objects, how ramps, textures and procedurals are integreated are great for artist. And the layering of materials similar to photoshop layers is also good.
How something like this could be integrated in Houdini is a different history, but it is definitely something SESI needs to look at, if they want Mantra to be more widely adopted.
The times for specialized shaders has passed, it is time for powerful uber shaders.

jordibares
From the point of view of FX I understand your point, you need the flexibility to bend it backwards.

But the important argument and the reason I am putting a bit of time writing this is because;

I should be able to, I should not be forced to

which is the kind of thing I feel Sidefx are embracing (thanks) and the kind of thing all the new users come to expect and demand.

It is not I want anyone to remove the possibility of getting your hands dirty, is that I really feel I should not battle away little tiny things any simple 3rd rate 3D package does out of the box and Houdini does not.

We have a great tool, great render engine, sub-standard material/shader set, not much to ask I think to improve that by providing, like Arnold, a solid standard shader and utility shader that get us to produce much faster and better, something that I am sure the community will appreciate as suddenly the user base will grow and flourish.

If SideFX does not, a lot of people will take the “foolish” decision that makes economic and practical sense at the expense of everything else and you know what? it won't be the end of the world as for the last 20 years has been constantly proved.

Let's never forget VHS won against BETACAM please

jb
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Pablo Giménez
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lisux
The times for specialized shaders has passed, it is time for powerful uber shaders.


How much quicker is it use these uber shaders?
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Well it is mostly a trade off between performance and usability.
Performance has been increased a lot in last years with improvements in shader compilers, so a well designed uber shader performs quite well compared
with a specialed one. Always talking about the usual scenario.
But the difference in usability is huge, lighters only need one
Swiss army shader, don't need to learn something new for every show,
this makes a big difference in artist time which more expensive
than machine time.
You also don't need a big shading department just a few people
manteining the core shaders for the studio.
The pipeline is simpler and tackle buggy shots is much simpler
because you don't have to deal with a collection of shaders.
So basically the total gain in work time is so big that is more
Important than any small under performance done by a more
generic shader.
The only area where you need spesialised shaders is in FX,
to make some lighting trickery or if you are rendering some
particular surfaces like human skin or hair.

MartybNz
lisux
The times for specialized shaders has passed, it is time for powerful uber shaders.


How much quicker is it use these uber shaders?
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Pablo Giménez
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I disagree.

I am not going to build a house with a swiss knife

I'd use multiple tools. A general purpose shader is certainly good for many surfaces, definitely more than 50%, but not for everything. The best choice is use both a good general purpose one and very specialized shaders. Aside skin and fur, also physical metals, foliage, metallic paints, cloth, glass… and more. Layering also plays a big role in look development and sometimes you want energy to be accounted between layers, let's call this “physical-plausible layering” while some other times not (see layering in disney principled). Finally there is a component-based approach as you can see in Blender Cycles.

So, no “one shader to rule them all”: there is no single BxDF to handle everything. You do need a general purpose + multiple specialized shaders, using different bxdfs, and each of them depends on its own parametrization / UI / UX.


P
paolo berto
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The specular models in VEX are pretty outdated now (phong and blinn models dominate) but aside from that the surface model VOP does most of what anyone wants in a single layer. But did you know, when using PBR, you can layer an arbitrary number of surface model VOPS, using mix, add or whatever, with a very small cost in render time?

This is a HUGE benefit to mantra, that BSDF models can be mixed so easily in VEX without a large performance hit, If you don't like the specular lobes you get from the built in bsdf models you can just layer several together to shape it the way you want. How many other renderers will allow this kind of free “bsdf sculpting”?

As a long time lookdev artist, to me this is a ‘killer’ feature, and obviates the need for a multilayer node.
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pberto
So, no “one shader to rule them all”: there is no single BxDF to handle everything. You do need a general purpose + multiple specialized shaders, using different bxdfs, and each of them depends on its own parametrization / UI / UX.
P
Mmm I believe this is the same thing I put in my previous post.
Anyway I don't want to begin a flameware between specialised vs über shaders, this has been discussed many times before.
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Pablo Giménez
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jparker
But did you know, when using PBR, you can layer an arbitrary number of surface model VOPS, using mix, add or whatever, with a very small cost in render time?

Yep, and I really like it.

This is a HUGE benefit to mantra, that BSDF models can be mixed so easily in VEX without a large performance hit, If you don't like the specular lobes you get from the built in bsdf models you can just layer several together to shape it the way you want. How many other renderers will allow this kind of free “bsdf sculpting”?

Yes, Mantra was actually the first commercial production grade renderer with such ability, to my knowledge.
More in general OSL solves this “by design” since you code in the renderer the BSDF and you don't do anymore light loops. Blender Cycles is able to do so and I believe Sony's proprietary Arnold supports it too. Appleseed can do it too but there is no shading language (yet). I am sure many others can be added to the list.

Shading language wise I expect this to be possible in RSL-based renderers: 3Delight's Path Tracer now has hardcoded BSDFs so as soon as you can avoid using illuminance() this will go to town. Same for PRMan.

As a long time lookdev artist, to me this is a ‘killer’ feature, and obviates the need for a multilayer node.

I was more referring at layering multiple materials each with a thickness and energy interchange, but in term of layering/shaping of specular yes this is absolutely cool.
paolo berto
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Follyx
Hi,

before I changed to Houdini I was over 14 Years a Mayauser and was used to download different shader librarys as a starting point for own development.

I dont find anything similliar in the web for Houdini. Any suggestions?

Thank you in advance.

Cheers
I will like to go back to the original post because I do feel this is an area that could be easily improve by SFX. First of all I feel we are talking about materials library more than shading libraries. Semantics I know, but I relate shading to shading models.
I understand the material library in H15 has improved dramatically since previous versions. But the lack of even commercial expansions in Orbolt makes it inconvenient for basic setup.
A wide library for initial setup is quite usefull, I will say essential in a workflow with tight deadlines. It's true that you almost never end up using the shader as it comes from the box but it helps a lot when experimenting looks.

Jordi, you mention this in your guide when you write in the shading chapter that:
Over the years I built a big library that can handle 90% of
a job making my life very easy.
As I am now working exclusively with Houdini I have done
the same for Houdini and I am in the process of redoing
all the materials but as you can imagine this will take me
a long time as I had to start from scratch.
PS: thank you for the guide.

I also understand the concept from SFX of not developing tools to specific needs, and any medium or big studio probably have their own library. But for a small studio or the independent not having this starting point does affect the time of production and therefore cost of the project. And like I said this is something that for a team in the long term can be developed gradually and made ready available to the users.
https://www.imdb.com/name/nm8408875/ [www.imdb.com]
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i with you 110% what you said Nicolas

building materials is very hard to start with until Side FX change
and i quote from my this post

“Houdini lacks any graphical representation from each node using materials

maybe side fx will look into this for version 16 - 17 ?

Maya Max ect all have graphical representation for materials nodes ”

and not having say 100 materials start of with does not help

if you look at all the other render company vray (reanderrman for maya ) maxwell render modo. ect ect they all give you “very large free library materials”

But because building materials with nodes you can not see make not intuitive and not fun at all

This were Side FX really look like its in the stone age if was fun and easy there would be tons materials a round,
yes I understand Houdini has incredibly powerful materials deep under the hood. but get to them and understanding them take long time not easy at all.


(did point out here on different subject )



https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=42965&highlight=Substance+Designer [sidefx.com]
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from my point of view, i never used any material library.
you dont know who build the library and what kind of hidden bugs he has there.

I always prefer to build materials from scratch. It seems to take longer time, but if you compate it to time needed to investigate what was done in material library you downloaded and how to modify it to your needs (i mnot expecting that you would use material as it it, without changing) its still more valuable.
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Hi there,
the new principledshader is like a universal material lib. It is so easy to setup 90% of all materials needed now. I am very happy with it.
The rest would be textures and there is plenty other sources for that.
Plus you have great noises and some procedurals in houdini.

Maybe you should look at the great tutorials:
http://www.rohandalvi.net/textures/ [rohandalvi.net]
http://www.rohandalvi.net/shader/ [rohandalvi.net]

They where like an eye opener for me and speeded up my learning curve.
The tuts are not for free but worth every penny.

regards

Olaf
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