Hello.

I am having trouble getting mental ray to work with houdini. I've serached and found several scraps of info on how to make it work, like these:

http://odforce.net/wiki/index.php/MentalRaySetup [odforce.net]

But Still, can't make it work. Here is what i do:

Installed MR standalone, then setuped the env variables from houdini like this:

MI_LIBRARY_PATH CProgram Files/Autodesk/MentalRayStandalone3.6.1/lib

MI_RAY_INCPATH CProgram Files/Autodesk/MentalRayStandalone3.6.1/include

MI_ROOT CProgram Files/Autodesk/MentalRayStandalone3.6.1

Then in the mental ray rop i set the path to the exe file, and hit render. Two things happen: 1. Ray.exe pops into task manager and takes 50% system resources; 2. Houdini console pops and says:

RC 0.2 warn : unknown filetype mplay, assuming rla
RC 0.2 warn 082008: jittering disabled because max samples < 1

But no images are to be found. Can anyone explain how to make it work?

Also in the following thread:

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=14056&highlight=imdisplay [sidefx.com]

… they discuss how they are making the houdini player to open the images from MR, but they speak on a godly language that my simple mortal soul cannot comprehend. Any guides out there for the simple creatures?

The link you posted to the od suggests rendering directly to imf_disp.exe instead of mplay.

ray -imgpipe 1 | imf_disp


Any luck with that? [wikipedia.com]

No. It returns:

MI 0.0 error 121001: failed to open ray or ray.mi for reading, The system cannot find the file specified.
MI 0.0 error 121001: failed to open | or |.mi for reading, The filename, directory name, or volume label syntax is incorrect.
MI 0.0 error 121001: failed to open imf_disp or imf_disp.mi for reading, The system cannot find the file specified.

even though the files is there. It just doesn't want to render. It generates an image file, which is broken, cannot be opened

small bump. please, can't on one really help?

bump. If i am asking stupid questions do tell. But, like, is no one using MR here?

AFAIK there are not many mr users around here…

have you tried an autodesk/mi forum?

mental image's forums, the Houdini subforum, the last message is from Nov 2007 year.

And why is such a low interest in mental ray? The translator doesn't cover everything in houdini, or what?

jjobride
mental image's forums, the Houdini subforum, the last message is from Nov 2007 year.

And why is such a low interest in mental ray? The translator doesn't cover everything in houdini, or what?

This could also be due to the fact that a lot of people use Houdini Apprentice and Apprentice HD, which do not support 3rd party renderers like MR or RenderMan.

and that renderman and mantra are better and faster ( )and you don't need to know C to write shaders, and there are far fewer people around who do use mr?

with all respect sir, but i didnt see any mantra shader similar to Mental Ray MIA materials. Which are one of the best shaders i`ve ever used in my life.

I have done great arch and design materials with it

Maybe i am totally wrong…

Is there any thing similar to?

I don't know all that much about the MIA materials but from what I can tell it wouldn't be that hard to replicate in mantra

and as for mr use - it's not always about actual quality - number of users, lic cost, rnd costs etc etc are often more important factors in choosing a renderer.

Being a big mental ray user who uses the mia_materials all the time when I am using Maya…I only wish I was using Mantra instead or at least had a vops like workflow and nodes. Mia and mr are great single minded shaders but playing with vex and vops is the best kinda fun in shader land.

I don't really see why you would need to use mental ray with houdini.. as others have pointed out there are advantages to using mantra which already comes with it so this is likely the reason why you aren't getting much input as probably no one here is familiar with using it in houdini.. however if you want to use mental ray within another package like 3ds max there are ways to export different digital assets to other packages so you can render within that package using mental ray.

As someone who has used 3ds max before, the power of the vex shader builder simply is on another level than anything offered with a package using mental ray… also mantra definitely is quite a bit faster in my experience.

EDIT: as someone else pointed out.. apprentice doesn't support 3rd party renderers.. so do you have a commercial license? If you do then you should contact side effects for direct support which they should be able to provide.. if you are using apprentice than you have to give up on it since its not possible to use mental ray with apprentice.

Sty.. what you are referring to are just pre-made shaders / materials that give a good output and you are correct that within houdini there isn't really anything on this level that is “pre-packaged”, rather you have to use the vex builder and / or play around with the existing materials they provide to get the output you want but any shader offered for mental ray can definitely be replicated within houdini and a great deal more customization can more easily be attained than it could for a mental ray shader due to the node based system rather than having to write custom code for the shaders (in mental ray)

maybe if we think about integration mantra is excellent.
but for stuffs like global illumination mantra is not as powerful as mental ray.
using the old vex GI light is just counting 1 bounce, and with PBR is too long to get clean render and the result … i still preffer mentalray.
btw if u want to use mental ray u have to use c to compile your shader..
i wish theres a phenomenon builder for houdini that would be awesome.
and as for the speed.. i think we did try to benchmark modo and houdini (on odforce) i think the result is still modo is faster and the quality is also better.
i think to get the best we should mix and match
best regards
Patar

I've had great success with MR and Houdini, it's a very good renderer but like anything else has it's strengths and weaknesses. Can't help you on a Windows install but if you're still having trouble in *NIX land, let me know.


Mark

alright, thanks for the information everyone.

Hey Patar i am going to build a new pc with at least 8GB of ram, so i really would like to make some benchmarch tests comparing speed.

But in my personal Tests i got that Mantra is much more faster with Displacement and Fur than MR…thats very noticiable!

About GI and FG (which has different name in Matra) i really need to explore more!

best regards


Sty

sty its only natural for mantra to be faster with displacement compared to mentalray due to its reyes algorythm almost all reyes renderer are…we r talking about raytracing and GI

http://www.dctsystems.co.uk/Houdini/hKickstartPrman.html [dctsystems.co.uk]