I do not quite get this all pc mess.
From what I've read and thougth pointclouds are fully loaded into memory because they are not partitioned…(a few sentences about TBF here ).
That makes them pretty useless in big scenes.
That's why they use octrees in prman and some other. Octree is a mipmapped structure for efficiently wrangle pointclouds, and prman has it for a couple of years now.

Also…this octree is easy to implement and there are some ready and free pieces of c++ code on the net.

So…if houdini has quite mature pointcloud functions now, where is this octree thing 8) ?

It's funny, pointclouds are used to make rendering faster and more memory efficient, and now in houdini they are not as useful because of this tiny little lack of tree :shock:

This subject comes from time to time without any solution.
Can you put some raytraced area light on it

Sorry to be late for dinner.

Thank you for all the info!
eetu, it seems like I it resolved my problem!

I was sure I checked all parameters but as it appeared…I hAven't.
Now I can fully control micropolys and pointcloud.
Should be nice for low precision non flickering attribute cache for tons of unconnected geo


Peter

hehe, Just spotted “advanced dicing control” in houdini help .

EDIT : I've set “uniform measuring” and “measure scale” to 10 but it didn't helped much.

Perhaps pc count changing from frame to frame isn't a big thing
and pcfilter copes with such things well :? ?
Could you guys elaborate a bit on this subject?
Is it common to use pc's on animated geometry?

It's all about pointclouds and deforming geometry.

I hoped it'd be easy to create a consistent point cloud with non changing nr of points using pcwrite, but there arouse some obvious problems.

When shading quality is set to 0, no dicing happens (as I understand it) and pcwrite creates one point per primitive.

It is not very useful with coarse unclean geometry.

When shading quality is >0 mantra creates more micropolys and pcwrite creates more points, but adaptively, so they flicker and change nr and all that mess.

Is there a possibility to force mantra (pcwrite) to create arbitrary pc denser than a point per primitive?
In other words to dice non adaptively?

I know I can create pc using scatter SOP and bind point to geometry but … there are other thingies there.

I was thinking micropoly, but perhaps it is possible to pcwrite from micropoly and use pc in raytrace
:twisted:

Please correct me if I'm wrong but isnt't point cloud method quite convenient for all kinds of animated effects with constant topology objects?

While using pcwrite (and mantra told not to cull micropolys) to generate pointcloud from micropolygons, we get samples always in the same positions (moving with geometry points) which avoid resampling problems like global illumination flickering.

Complete weirdo or just a little :?:

Thank you very much guys!

It looks like working, but the file downloaded is 49 bytes, not 17 KB and is definitely not working.
I tried from different machines using different browsers, still the same.

Thanks, I know about AXYZ but it's for sure AXIS (Glasgow afaik) and it's fakes SSS just like chanlum for LW and Cinema : http://www.happyship.com/lab/chanlum/documentation/index.html [happyship.com]

I cannot download this shader from exchange. Can someone who already have it try to post it somwhere else? I don't know if the file is busted or what?

Thanks

A bit OT.
What is unique about this very image is it's source
It's an example of krakatoa:

http://www.franticfilms.com/software/products/krakatoa [franticfilms.com]

The problem is not in doing a turbulent dissolve effect which is fairlu straight forward, but on doing it on huge amount of particles.
You hit a million particles with a modest size 1k image, and well… people write inhouse renderers for things like this.

Edward!

Thanks!

The problem was $PT as you wrote.
The rest of the mess was from my testing.
The “offsetFramesCreate” just created an attribute with exact offset value in frames to check its values and avoid errors.
I tried a lot of things…CHOPS, different expressions, shifting by frame, shifting by time.
It'd probably take a very long time for me to get to TPT which I didn't know about. Mysterious enough

Thanks a lot.

Perhaps this was not too clear
What could be the simplest way to offset animation based on particle attribute/event.
Animation should start when a particle hits collision object.
The details are in my former post.
This should be really easy but I have some unusual troubles.

This is very easy in theory and practice, but produces some errors.
There are some particles falling (colliding) with the floor, and there is a ball with animated radius.
I want the ball to be copied to a particle when it hits the floor and ofcourse it's animation should start at that moment.

I tried several ways, ended up with creating an attribute which value is the exact nr of frames (or time - to limit rounding errors) of which a copy animation should be offset.

The value checked in spreadsheet is ok I checked it frame by frame, no matter if the particles are cached, roped to file or played frame by frame.
The problem is that some copies are offset good, while the others are completly crazy and does not reflect my offset attribute in any way.

What could this be? I'd be grateful for any links or thinks .

ah so!

Thanks, it just need to have the exact or larger nr of samples.
So if my sequence counts 200 frames, I have to set to frames, start:1 end:200 sample rate:1

My problem arouse because I downloaded some sample hipnc with the similar setup, and the only difference was nr of bgeos (geometry chop settings apart from “animated” were default)

Thanks Andrew

What is the matter with geometry CHOP and importing animated bgeos?
It does not take bgeos of lesser count than current FPS*10 or am I a complete weirdo?

There was a default scene FPS 24 timeline 1-240 and I tried to feed my geometry CHOP with 180 frames (bgeo) of test sphere…
Static of course worked ok, but animated needed at least 240 frames to play.

There's nothing in documentation about this thing.

I didn't notice it before spending two days of looking for possible mistakes

Is it possible to override switch shop input parameter using material SOP?
I play with it and wanted to randomly distribute some shops on prims.
I have material node with switch and 3 simple shops inside.
Input param is referenced right in material node.

I easily use this technique with VOP switch, and it just works.

thanks

Hey! Remember an old Alias|Wavefront ad?

“Houdini is not a piece of software, it's a way of life”


:twisted:

Hey guys,
I was a bit offhoudi last year.
But I'm constantly following every small step of sesi hahaa.
Out of curiosity I installed H9, and loaded my current project geo 600 k of polys in one object. A settlement.
It turns out that eg in ambient occlusion mantra is faster than my basic vray setup!
What Da Hell? Still this scene is very basic but hey, last time it was lagging far behind :twisted:
Does anybody have the same experience, perhaps with other features like full blown GI? Glass rendering or something?
I'll do more excessive tests but not in next 5 mins
:roll:

From my point of view it looks like this:

-Houdini is not a fast modeler, and it'd probably never be because of the main idea of this software. As raging Reggie says among many mistakes… it's often not neccesary to have history in modelling and it's faster to delete/rebuild than to search for a node/change parameter/ohmygodnowthatswhatididn'texpect/repair errors.
I often find myself trying create something too clever and complex for the current needs.

-What is very powerful you can model in any soft you like and plug the geo into whatever doing network (say scattering spots), if you like to change the model, the network is reused and you keep free.
Any modeler can work as a plugin for houdini, treat file SOP as model SOP

-If there is a need to experiment with different modelling ideas, no software gives as much freedom as houdini. You are able to build extremely complex geometries using a few sops, apply custom networks to different models, test, change, create and this is SO VERY UNIQUE.