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I need some help please with Houdini

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Hello everybody!

I hope everybody ok?

I have couple questions that I no find answer. I search this site and houdini site but nobody ask this before , so maybe me crazy?

1- I don't understand why Houdini make a box as default primitive when I try to make new geometry? I have to always clear current geometry when modeling. Me not understand why houdini make object that i must delete.

Can anybody explain benefit for this?

2- I have Mental Ray stand alone license when I buy Softimage XSI. For me to render with mental ray in command line, I have to source XSI environment variables then run ray3.exe in command line.

Problem in houdini, i only see param called ray? How i can source XSI environment variable so i can render with mental ray? I no see anywhere where I can use my own script to call the environment vars and call ray3.exe. I use windows, sorry :(

If there is tutorial somewhere please show me link.

Should i ask this question in Mental Ray section?

3- Do we have particle goal weighting in Houdini like maya? If yes, what is proper term for it in houdini? I know every software name feature different and since english not my 1st tounge maybe me not understand what houdini call it.

I like much houdini. I read old post here before i ask question here. Everybody seem very nice, I hope everybody nice to me and patient.

Thank you for help,

Michael M

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1. Whenever you create an object a creation script is run. In the case of the geo. object the following script is run. $HFS/houdini/scripts/obj/geo.cmd

If you don't want to have the default box created then you can removed the following lines.

    opcf $arg1
    opadd file file1
    opparm file1 file defgeo.bgeo
    oplocate -x 0 -y 0 file1
    opset -d on -r on -t off -l off -s off -u off file1
    opcf ..

2. Sorry, I don't know.

3. You could use the Attractor POP.

jim.

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Hello Wolfwood!

1-Ok I remove those lines from script.

But I don't understand still why houdini create box I can't use? Maybe I no understand meaning of box with no use. Or is there use for this default box that I dont know about?

2-I hope somebody know how to use metal rray 3.1 with houdini.

3-I study now attractor pop. Thank you for translation.

Thank you for help,

Michael M

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1. I think the reason why Houdini puts the box in there is because it's generating a new local coordiante system for that object and the box is just a handy way to show users that the object is there and how it's oriented in the world. That's all, there's really nothing to it other than some visual feedback for the user. Otherwise you'd see nothing in OBJ, or maybe a pivot sitting at 0, 0, 0 in the world.

2. I don't know much about XSI but if it really does have a standalone License of Mental Ray, rather than trying to source XSI's variables, you could maybe try just making some enviroment variables that Houdini can see. Add Mental Ray's /bin or wherver the renderer is actually located to your PATH and if Mental ray has a tree and/or a shader tree variable add those as well. Right Click-> My Computer->Advanced=>Environment Variables. Adding new variables that Houdini can see should have no effect on MR in XSI. There Should be a list of MR's environment variables somewhere in XSI's docs.

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Hello Mcronin!

1-Thank you for answer. Now I understand why box is made. I think, I leave it alone and not delete it from script. Just incase somebody else use my computer for houdini.

2-You give good idea to me. Right now XSI has environment variable file called setenv.bat. I find part where it setup mental ray paths:

Example:

--------------------------------------------------------------------------------

rem Detect P4 or better

set _CPU_REVISION=-p3

%XSI_BINDIR%\cpuinfo.exe

if ERRORLEVEL 15 set _CPU_REVISION=-p4

rem Render variables

set XSI_EXT=dll

set XSI_CPU=nt-x86

set XSI_CPU_OPT=%XSI_CPU%%_CPU_REVISION%

set XSI_USERHOME=%XSI_USERROOT%\Softimage\XSI_3.01

set MI_ROOT=%XSI_HOME%\Application\rsrc

set MI_RAY3_SERVICE=mi-ray3xsi3_0

set MI_RAY_HOSTSFILE=%XSI_USERHOME%\.ray3hosts

--------------------------------------------------------------------------------

I can make thiss environment varible in my computer like u say. The part I no understand now is houdini.

In the outputs, it call command ray -args to render. But for mental ray 3.1, me think command is ray3.exe -args

Where I can change mental ray preset settings? Is there script file I can edit somewhere?

Thank you to everybody who help me.

Michael M

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Hi Michael

You never said if you're using the full Houdini or apprentice? If oyu're using apprentice then you're out of luck with mental ray. Apprentice will only output to mantra...

If its full then....er... um.... well I'm not sure since I've never used mental ray :)

I'm sure someone else out here knows..

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Hello Marc,

Yes I use Apprentice now version 5.5. I can't download version 6 because my internet too slow now.

No output to mental ray? Ok maybe that why I have problem!

Sorry for bother everybody, I did not know it blocked.

Good you tell me otherwise I break computer until me make it work. I have hammer next to computer desk! (i joking)

Thank you for help everybody,

Michael M

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I can make thiss environment varible in my computer like u say. The part I no understand now is houdini.

In the outputs, it call command ray -args to render. But for mental ray 3.1, me think command is ray3.exe -args

Where I can change mental ray preset settings? Is there script file I can edit somewhere?

Thank you to everybody who help me.

Michael M

Well it may be a moot point now, but just for your info...

If the directory where Mental Ray is installed is in your system PATH variable you could probably just type ray3 -args into the render command field of your MR ROP and then scene should render. The Render Command field basicly is the command line. I don't think there's anything hardcoded into Houdini forcing you to use ray rather than ray3, but I could be wrong. As long as your system can find ray3.exe through the PATH I wouldn't think there'd be a problem. There might be a problem if something is radically different about the version of MR in XSI making it incompatible with Houdini.

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This very good information!!. I write this down now so that when I buy houdini I can make it work with mental ray.

I don't think xsi mental ray become problem because I buy license so I can render with any program that output mi2 file. I sometime render mi2 in command line.

At first i no understand why mental ray is blocked in houdini apprentice. Now i see, because of free version and houdini stamp on picture.

1 last question if anybody have time. It's ok if nobody answer, I study this soon.

It look to me many houdini masters come here but not many have much mental ray experience here?

I not trying to be smartyguy. <-I don't know right way of saying this joke.

Why? You only use mantra for raytracing? Mantra is very good? Maybe I study mantra too!

I have bad experience with maya and max renderer so me think all default render no good and slow.

Thank you everybody. You help me alot and save my computer life:)

I now study attractor pop, me like houdini very very much. My wife get scared because I have too much control and I no go sleep!

Thank you very much!

Michael M

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I think you will be pleased with Mantra. :D

Its up there with RenderMan (prman) and Mental Ray.

jim.

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Which actually brings up a question I've been meaning to ask. Which scenes in the Time Machine was mantra used on? I know Jason mentioned the NY scene but anything else?

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There are some people using Mental Ray with Houdini. It pops up on the mail list from time to time. If you get no MR help here, you could always ask there. The mail list seems to have a denser population of brainiacs who respond regularly.

http://www.sidefx.com/community/interact/l...serv/index.html

Give Mantra a chance, though, you won't be disappointed. There's a world of difference between Max and Maya's default renders and Mantra. I noticed it the first time I rendered anything in Houdini. There's something to the image quality on even the simplest scenes that's present in both PRMan and Mantra that sets them apart, especially if you are looking at Max's default renderer.

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Thank you to everybody.

I study Mantra today. It's pretty good! I not know it used in Time Machine.

Too bad it only use 1 processor for rendering in apprentice version. I study more but me like particle best.

Also, thank you to everybody for being nice to me.

Michael M

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Which actually brings up a question I've been meaning to ask. Which scenes in the Time Machine was mantra used on? I know Jason mentioned the NY scene but anything else?

It was used on everything (except for the volumetric elements) - and even in shots that were omitted due to storyline changes, so:

The Time machine itself, and the Time Bubble

The cars in the garage when he's shooting through time

The greenhouse and vines, planters, boxes, etc

The exterior shots (canyons, plains, snowscapes)

The glacier and the ice-cave (omitted)

The big New York shot (all of it)

Cave interiors

The Uber-Morlock (except is hair)

We used Renderman only twice (for the field of grass and UberMorlock's hair) and tested one shot using mental ray for it's GI capabilities, but canned it ultimately. So I'd say that mantra rendered about 96% of Time Machine.

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I have never seen the Time Machine, only the old version. (I bet you weren't even born yet back then ;))

But sounds impressive, so I ought to see it. Even if it was just to see some nice work rendered with Mantra :)

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You know it's actually a suprisingly good movie, and the DVD is pretty good as well. It has some decent behind the scenes extras, and it also has a deleted scene that probably should've stayed in the movie. A couple of the time travel sequences are fantastic. Well worth the rental if you haven't seen it.

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The bats were renderman. I'm not sure what we used for the moon sequence.... so much displaced memory issues....

:)

-k

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