Hi,

I am really wondering why houdini does not have one like after burn.
I mean it can be Maya fluid shaded particle clould to start with or customize with, but there are almost no such a things and also plug-in for Houdini…..

The point that I want it is I do not want to use copy and stamp volume way and instancing also. Because both way possible to take a long time to generate ifd.

I know the big company has own tools does that only in randering time.

I am not saying I want that good stuff but I'd like to say I need something like that like “Vray procedual volume shader” which takes per points attribute for noise, scale, rotation, etc kind of stuff.

I hope many people are thinking same way.

So I really appreciate that someone can tell me where I should start from or give us really simple example Hip or source for the HDK.

Cheers

Doing Afterburn type effect is pretty easy and already in Houdini. You're just looking for a one click solution.

A very ‘simple’ one is to create 10-20 volume density noised up balls, and write them out.
Then create a particle system or points that has a Id number to specify which type of ball to use. And then you can delayed read instance them onto the points at render time. You can also create a bunch of orientation and scale attributes in sop land.

Add one of the volume shaders, make some lights with depth map shadows, check your step size. Render!

And then, tweak, tweak, tweak, tweak.

I've done the same similar setup and it's worked with great success, and with a bit of work you can integrate it into a procedural.

Hey rtanrantino,

I know what you mean. I haven't found any simple and efficient solution do render particle cloud in Houdini.

The problem with the delayed load instance you propose ratman, is that for example if you render 50000 points, it will take 1.5 minute to translate the data to Mantra while you read “Evaluating Python” at the bottom.

It is actually the same problem with regular instancing mechanism.

If you look at the metaball as volume recipie from the FX tool bar downloaded from the Exchange, then you miss a lot of flexibility because you cannot plug any regular volume shader like the Billowy Smoke. Your custom shader has to deal with noise creation inside a meta-ball loop, same thing for the displacement. Besides, you need to bake your point every time you press render which is quite annoying.

I haven't had the time yet to look at that but I think the only good solution to create particle clouds is to create a volume sphere at render time via the hdk.

I asked SideFx about but they don't seem to think it's a good idea. Instead they keep telling me to use meta-balls or pciterate inside a vex volume procedural.

Has anyone created their own particle cloud per point with the hdk?

François

francoisd
Hey rtanrantino,
Has anyone created their own particle cloud per point with the hdk?
François

Yep.

8)

So I guess I'm right to think procedural volume creation is the way to go

I'm actually on that now. I've managed to compile and setup example files. That's gonna me my first hdk project. I'm planning to to do a combination of VRAY_DemoVolumeSphere and VRAY_DemoStamp. I'll probably missing how to bring my points from Houdini instead of creating the scattering inside Mantra.

Anyway if you have any useful information for me, I'll be happy. Actually I'll probably get what I'm missing from your clusterThis.

Thanks

François

P.S.: I still think this should be part of Houdini by default like we have sprites and other similar stuff.

Cool! Go for it!

You'll find you have much more performance & flexibility.

And share some of your work if the mood strikes you.


Take care,
Mark

francoisd
Hey rtanrantino,
The problem with the delayed load instance you propose ratman, is that for example if you render 50000 points, it will take 1.5 minute to translate the data to Mantra while you read “Evaluating Python” at the bottom.
It is actually the same problem with regular instancing mechanism.
François

This might be interesting to you as well as it deals with instancing geometry without writing all that geo in the ifd through a custom VRAYprocedural:
http://www.peterclaes.be/blog/?p=151 [peterclaes.be]

In other posts it states how to do the instancing of delayed loads, but that would write the information into the ifd again.

I don't see why it would not make sense, it makes a lot of sense to me and it is very common to do when you start dealing with a lot of data.

edit: I haven't quite tried it with volumes yet, but it should work too as it is just another bgeo. I'll see if I can put some more examples together over the next couple of weeks and simplify the code as it is a bit cluttered at the moment.

francoisd
The problem with the delayed load instance you propose ratman, is that for example if you render 50000 points, it will take 1.5 minute to translate the data to Mantra while you read “Evaluating Python” at the bottom.

Yea, this sounds like when you're generating an IFD to then be passed to mantra. If mantra is reading that geo at render time, then you'll not be waiting for the “Evaluating Python” message.

And if you're clever, you can figure which part of the data you need to load, e.g. slicing.


Over-n-out,
Mark

Thanks guys. I really appreciated it.

Thanks Ratman,

I could test many things in Windows environment because of you.
I really want to know how to use Cygwin to compile make file for linux by the way. May be I should post as other thread.

Francois

Thanks for help me out. I guess I needed to explain more ……

And I would say what I said “Big company has one” was for I guess Render man and not for mantra yet.
But I guess mantra can handle them as well right??

mark,

fist of all, thanks for the Cluster This,
But I still have problem with windows….. I know you don't want to do with windows…. then …. Please Ratman we need you!!

Pclaes,

I have checked your HDK, but same as ivan said it did not work for windows….. same problem. I can compile without no error but mantra won
t be able to find it…..
I got both windows and linux environment so,
personal i dont care OS but I can't use or implement it at work.

Anyway,

Thanks a bunch guys!!

I think cluster this is the way to go for the best
but,
I think pclase instance is also really really nice.
I said, I want deal with volume,
But instance is necessary all the time I would say.
And for now I can not wait to generate some millions of instances of ifd for couple of hours.

If there are these 2 nice things added in Houdini(as a default or learning purpose or for customize), Houdini Rocks more for sure!!

One reasone is
I had started learning C++ from nothing unfrotunately,
but I can see still looooong way to go… or I say I suck….
or I mean there are things that needs to learn day by day rihgt?
I am okey but others???? I would say those “Artist” go for FUME FX for sure!! it's pretty solid!!

I would say one more thing, it would may be for Houdini 12……
Multi thread Dops and Pops (any conditions are acceptable but we need multi thread basis…..)

Then I hope WE ROCK!! Right??

I got my procedural working and compiled on windows 7 64bit.
I'll see if I can write down the steps in a next blog post. (and perhaps put the dll's online too so you don't necessarily need to compile.)

Thank you so much Peter.
I will definitely check your blog!!


Since Houdini version up constantly,
If somebody can share the better document for compiling for windows(including how to use makefile),
I would really appreciate it.


That is because,
I think linux is even for free to use, many people need to use windows because of the other plugin or pipeline or etc.


Houdini forever!!

Actually you don't have to use a MakeFile in many cases, just hcustom will do. However it is more complicated to compile on Windows. One thing for sure is you need the right compiler.

For H10 it's Visual Studio 2005 I think. The problem is this is not free and they don't sell it anymore anyway. If you read the forums, some people will say you can use the Express edition if you download certain update packages but honestly I tried very hard it only worked with the standard edition, not the Express.