curtesy of mr. Ternece ‘change my desktop skin every day’ Neoh.

attached are two screen shots from the above example… one with the uv projection set to vertex and another to points.

Hi wolfwood, ya I've given up on getting the uv & ‘render as subd’ working. But now I seem to have a similar problem when using the subd sop… argh.

I've been trying to make this work the whole day.. but the more I try the more confused I get.. I'll give you a quick example:

Create a tube sop (Polys, quadrilaterals, y axis, height:5, 4 rows, 10 columns)

Add an edit sop (select the inner edge loops and scale or move them up respectively down to the tubes end loops, so the tube will have hard edges when subd comes on.. not that it matter with this geometry..but anyway)

Add a uvproject ( vertices, cylindrical & press initialize)

Add a subd sop (depth 2)

Add a shader with a checker material or something.

Now look at the tube, there is a seam which is warped. If you go to the uv view and check the layout with the subd sop viewable you also see that the mesh is smoothed at that ‘seam" as well. If ’smooth vertex attrib' is checked off, the mesh goes back to a more predictable form, but alas the uv mapping is gone bonkers as when using the ‘render as subd’ does.

So… how do I get this to work? shouldn't the subd sop be able to subdivide the low poly mesh and keep the UV mapping locked on its surface?

Peter

so you mean doing your uv mapping in vertex attributes, and promoting that to point uv attributes? That has so far given me very bad results.

Is there a way to uv map low polys so that what you see in the viewport is what is going to be renderer by the ‘render as subd’ option?

Sorry for being so daft guys,… but I fail to understand the reason behind having an option of ‘render as subd’ if it does deal with the textures properly. Most of the stuff that has to be subd'd is low poly meshes with uv textures hand applied… am I missing something here..? ops:

Peter

Hi Andrew, so I take it that getting the uv textures to behave as they do with a subd sop is not possible? If the uv mapping done on low poly mesh, with the subd sop for checking while working, then switching over to render with the ‘render as subd’ switched on (and the subd sop disabled) the textures will ‘slide’ and not line up as they did when checking/rendering thru the subd sop?

Hope this question makes sense… Just trying to learn the workflow in houdini… a shame to spend hours uv mapping and then pressing render and seeing all your seams slide all over.

Peter

hey DJ, did you ever figure this out? I also discovered that the uv mapping you see in the viewport / with subd sop on is different than when rendering as subd…

Peter

me too!

true true… slashdot is starting to feel like second home

Thank you all for the information regarding threading.

Hey Peter

Thanks for the info. I'm surprised houdini lacks advanced threading, when it's so advanced a piece of software over all. It's painfull to sit and wait for something to cook when 3 cpus are just sitting idle. Oh well, one day maybe…

Peter

Hey,
Was wondering if anyone had any thoughts on hyperthreading in linux when using houdini. I just recompiled a new kernel with HT turned off, due to the very bad performance in houdini. Almost all operations were only running on one cpu, and since they are virtual, performance was abysmal.
Is houdini optimized for threading? Most operations seem to only run on one cpu. I've only got mantra to use more than one, and that's by forcing it with the -h or -n flag. I'm surprised particle operations weren't taking advantage of the extra cpu's. Not even when HT turned off. To be honest, Houdini runs fastest on our amd 64 machines (2 gig, 32 bit OS, geforce vid cards), it feels quicker and more responsive than on a dual xeon 3.2 with 2gigs and a quadroFX1300. Weird no?
Anyway, just wanted to hear if anyone else had the same findings… could be me doing something wrong, I'm pretty new on houdini.

Peter

Hey JC, yup i hear you… slack takes awhile to get up and running in a workable state. Dropline-gnome made it a lot easier tho, comes preconfigured and has most of the apps i need, …gimp, inkscape etc. I'll have to take a second look at suse one of these days… heard lots of good things about it.

Peter

Hey, any reason you guys going for package driven distributions like suse / debian / redhat etc? We've had good performance with slack here, and I find keeping the boxes up to date are relatively painless as we got dropline-gnome as our desktop distro, which updates frequently to follow the latest releases in gnome… I know slack is a bit old school, but it's simplicity makes it quick to troubleshoot and tweak for performance, and with dropline ontop we don't have to lag too far behind the bleeding edge.
I've tried most of the other distros that seem more popular, but I find them confusing and overly complex once things go south. Perhaps I'm missing something? Is a distro like RH or suse better optimized when it comes to threads / libs etc?

Peter.

oups ops:

Hey JBG,

The horizontal apeture should be the size of the film back or ccd. In your case this is 35mm film, i dont think this will change even if telecined - though i may be wrong, id be interested to know.

This is what I tried first, but it was way off. The closest aperture for my shots, are around 18, which I kinda manually got by trying numbers for too many hours.

I just don't get it, maybe it's just me ops:

I'll email support for this, can't wait any longer, I've got 8 shots to setup and 3 days lost coz can't figure this out.

Thanks mate, appreciate your help.

Cheers,

Peter

Hey, our studio went thru a similar experience, where we shut down for 1 & 1/2 month just to study houdini. Before that I had been collecting video / pdf / sample files from the net so we had enough material to study. The best sites were: www.buzz3d.com and http://sidefx.vislab.usyd.edu.au/. [sidefx.vislab.usyd.edu.au] Most of the video tutes are a few versions old, but it doesn't really matter as most of the changes are easy to figure out (besides, it forces you to think and problem solve!).

There's also some good stuff around the net, do plenty of google searches and you'll find gems such as this: http://cade.scope.edu/courseware/notes/houdini/index.html [cade.scope.edu] for instance.

Obviously the two main houdini forums, this one and odforce is of great help too… searching in the archives usualy solves most questions.

There's also the mailing list archives, at: http://www.sidefx.com/mailarchive/ [sidefx.com]

Oh and one last thing, there is now a gnomon dvd that just came out. Lot's of good stuff in that as well.


Cheers,

Peter

Hey JBG,

Thanks for your reply, I found your thread on odforce a few days ago, but didn't really help, sort of just confused my even more. I'm starting to feel real dumb, I've done this countless times in brand X & Y, and never had a problem getting a “pretty good” match. And for this job, it's all locked off plates! Should be a breeze!

I must be missing something, because it can't be this difficult. I know the lens, I know my resolution… but what the heck is my horiziontal aperture? The information in the manual (search for aperture) is not for feeble minded ppl like me, it has stuff like “fovx = 2*atan( ( apx / 2 ) / focal ) = 2*atan( ( cam1/aperture / 2 ) / cam1/focal ) = 2*atan( ( 41.4214 / 2 ) / 50 ) = 45˚” - huh?

I just need to roughly match my cam to the real cam on set, doesn't even have to be that precise.. I'll tweak it by eye later… but right now I can't proceed as not knowing what number to put into the aperture has stalled me as it has such a big influence in the overall setup.

Cheers,

Peter

Hi all,

I can't figure out how to set the aperture in houdini. I've got footage captured with a 35mm film camera, telecined to pal D1 (720x576). The lens is 24mm.

I've read the tutorial called “real world camera matching” on odforce, but it seem to deal more with film resolution and not video rez. Jason Iversen had a comment on the page which stated “ And be aware that if you are working at video resolutions that you are doing the camera matching using footage that has not been optically scaled in telecine.” - So if it has not been optically scaled in tc, what should I put in the aperture..? Sorry if I missed something here, I've searched both sidefx and odforce forums but can't find anything that I can understand. Thanks in advance.

Peter

Hey,

It's very reproducable here… Basicaly everyone has it. I think it has to do with the wacoms tho, as the machines that has only a mouse, do not display these problems (same software setup on all).

Another way this problem appears is if you want to adjust your pivot, then it's impossible to select a choice on the pivot menu, as if the left click is not registred at all. The menu just sticks and wont go away. Escape is the only thing removing it.

I just tried working in houdini with a mouse, and after 3 minutes encountered the problem. This workstation has the wacom plugged in tho, and xorg.conf loads the wacom driver… Anyway… maybe that info helps, maybe not

Peter

We've got this happening on 6 out of 8 machines. Almost identical setups on all machines, been trying for the last week to figure out what's happening. This happens in both apprentice 7 and the beta for 8. After using the tab workaround for awhile, the viewport operations seem to degrade and in the end the menus will not work at all.

It's reproducable to some extent here,… start houdini, go to sops, add some geometry, slap an edit sop and start pulling vertices / tumbling the viewport / shifting views with space + 1,2,3,4 and the viewport starts behaving bad. What helps for awhile, is to go to quads (space+t) and select another viewport and work there, but after awhile it starts happening on that one too, so space+t and try another untill they are all giving the problem….then restart

Slack 10.1 + kernel 2.6.12/13 + dropline gnome + nvidia 1.0-767 + wacom-0.6.8

Cheers,

Peter.

Ps. Maybe it's not even a houdini bug, maybe it's how X / wacom / etc is setup… any ideas are welcomed… kinda desperate to get this resolved..

just resent to sales@sidefx.com, sorry… , my bad.