Revit 2009 / Mental Ray Workflow...

This is a very wordy multi-part post. I understand it's going to be too much reading for most, but I thought someone might find it somewhat useful, so here it is. Best of luck.

While the new Mental Ray rendering engine is a much needed and long overdue improvement for Revit, IMHO, its implementation into Revit shows a disconcerting recent tendency of the developers to flub new features. Furthermore, it has the fingerprints of Autodesk marketing all over it – an intentionally crippled rendering feature set. From what I understand, a limit of 4 cores for rendering, slower rendering speeds than Max, no photo backgrounds (you've got to edit an exported image using a third-party photo editor). The whole material dialog is a case study in poor UI design. Then there's the big kahuna – what we're here to talk about today – a completely botched material library system workflow.

Once you kids really dive into the material library, you might be shocked to learn that there's no easy way to store Render Appearance Materials (the Mental Ray shaders and/or textures – for brevity, I'm going to refer to them as MR Materials) for use in other projects. Custom material definitions reside within the project file, not within an external library, unlike previous versions of Revit. And there's one more subtle but very critical distinction – the MR Material is directly tied to the Revit Material.

The amount of work keeping this straight and using the various workarounds will prove to be a deal breaker for many, and will send users looking for alternatives – which is just what Autodesk is hoping for, since with the new FBX export, there's a very convenient workflow waiting in Max. See Marketing 101.

So, what's the problem?

First, it is rather awkward to share MR Materials with others, especially within an office setting or on the web. If you were hoping for some slick material file download sites like Maxwell and V-Ray have, where you can go to share and download materials, that's not readily in the cards since there's no such thing as a separate material file in Revit 2009. Also, no support for external shader plug-ins, etc. If you were hoping to have a neat material library on your office network, where everyone could share materials, that's not going to be an easy option either. There are some workarounds that we'll get to in a minute, but I know from experience how difficult it is to manage a shared library even under the old but easier AccuRender system. Throw in a few workarounds and hoops to jump through and the whole enterprise quickly falls apart.

Second, it's the workflow stupid. Here's where things get really complicated really fast. This is difficult to keep simple, and if you haven't already run into this issue, it may take a bit of a conceptual leap. The really big rub is: as it stands now, there's really no quick and easy way to change between custom MR Materials on a bunch of modeling elements. See, some users know exactly what the rendered materials are supposed to look like, and it's just a matter of tweaking those assigned MR Materials. I however use the rendering tool as a design tool – I often will try many different material and color palettes on a variety of modeling elements. If you're the former, this probably isn't as big an issue for you. If you're the latter, this presents a workflow stoppage...

EXAMPLE OF THE ISSUE:

Here's an example of the workflow stoppage: Let's say you're rendering an interior kitchen with lots of cabinets. You have a few dozen cabinet pieces, each assigned with a material called "Cabinet Finish". You're not sure what material you're going to use, so you want to try out a few custom MR Materials.

Under Revit 2008 (AccuRender), you would go to the material dialog, you select the material that's been assigned to your cabinets (e.g. "Cabinet Finish"), select the AccuRender Texture field, and select the AccuRender Material you want to use – either from the default library, or your own custom library, or by setting one up on the fly. If you want to try a different one, simply re-select your "Cabinet Finish" material in the material dialog and assign a different Accurender Material to it. The whole AccuRender Material library dialog is a bit outdated, but none the less, with a few mouse clicks, it's pretty easy to switch materials.

Under Revit 2009 (Mental Ray), you've got a problem. There is no custom library to access from the material dialog – only the default library provided. There's no way to add your own custom MR Materials to a shared library (only to your current project). Okay, so you look through the default library, but you don't find the exact wood grain look you're going for, so you cook up your own with a custom jpeg, and bump map, and you mess with a few settings. You do your rendering and decide you're not sure if it's quite what you're after. So you decide to try something else. You have one of two options. You can cook up another custom jpeg, bump map, etc. overwriting the old one. In which case, if you then want to go back to what you had before, you have to set it up all over again. Or, you can create a new (or duplicate an existing) Revit Material in the material dialog and setup your custom MR Material assigned to that. But now you're going to have to go through your model reassigning materials to a few dozen cabinet pieces. Try doing that a few dozen times on a bunch of projects, each time setting up materials from scratch or having to go through dozens of elements changing them from one material to another. See how much fun that is?

Here's a similar problem: You set up the Render Appearance for your "Door" Revit Material and now want to use the same Render Appearance for your *existing* "Window" material. How do you do it without re-setting it up or going through all your windows and re-assigning them to a different material? And then you decide you need to do the same thing with your "Trim" material. And after setting up all three of those materials, how do you then replace all three with a different custom MR Material without laboriously setting up new custom MR Materials? Now we're really having fun!

Okay, enough (for a moment) about what a mess this is, what features are lacking, and how the Factory seems to have so little understanding of rendering workflow. What are the workarounds?

There's one main approach I'm aware of... and it's been noted elsewhere, so I take no credit (or blame)...

This is also a case where the cure might be worse than the disease... only time will tell...

Edit: I've attached the templates as rvt and rfa file types, but it might make sense to rename them as template files rte and rft.

THE MATERIAL PROJECT

Two different methods to this approach, but both work on the concept of storing material definitions in a "Material Project file", and storing the Material Project files in an organized "library" of sorts.

Method 1:
1. In your project, you create the new MR Material.
2. When you're ready to save it to the material "library", you:
3. Create a new Material Project from the "Material Project Template" (this is a generic family template you create for this very purpose – I've attached an example template).
4. You recreate all the material settings based on how you set it up in the project (technically you could "transfer settings", but then you'd have a gazillion materials in your Material Project, and of course, there's no easy way to purge them).
5. You save the Material Project in the appropriate material folder (I've attached the folder structure based on the one included with Revit 2009).

Method 2:
1. You create a new Material Project from the Material Project Template.
2. You set up your material.
3. You save it in the appropriate material folder.
4. You flip back to your project and transfer over the material from the Material Project.
5. If you need to redefine the material, you flip back to your Material Project, make some adjustments and then flip back to your project and transfer over the material (over-writing the material that you'd previously transferred over).


IN PRACTICE

1. You're working on a project.
a. You have a material named "Door".
b. It's assigned one of the built-in Library MR Materials: "Wood Maple".
c. You would like to change the MR Material to a custom MR Material in your custom Material Project library: "Wood Fir". (btw, have these people ever heard of a Fir tree?)

2. You open up your custom "Wood Fir" Material Project from your custom material library.
a. You see that the material name in the material settings is named "Wood Fir".
b. You rename "Wood Fir" to "Door".

3. You flip back to your project.
a. You transfer the material from the "Wood Fir" Material Project to your project.
b. It asks you if you want to overwrite you existing materials (including "Door").
c. You select "Yes".
d. Your door's MR Material is switched from "Wood Maple" to "Wood Fir".

Further Notes:
a. You can keep only a single material in a Material Project file, or you can keep a group of related materials (e.g. concrete materials), or you can keep all your custom materials in a single Material Project file.

b. You can also use essentially the same concept by keeping your materials in a Material Family template. Families are a bit smaller and more portable and it's relatively easy to add new materials to a project just by loading in a Material Family file (I've attached an example Material Family template).

And just for fun...

Hi, although I am the junior here and only received 09 on Saturday morning and am blowing hard about this subject I know...there is so much to learn and not all is listed in the Help / User Guide !!!, but I have a distinctly uneasy feeling about this whole gig.

I cannot afford to buy into 3D Max, then spend oodles of time learning it, and then keep up with an exta sub system. This is starting to feel like being held to ransom.
I too want good options and user flexibility for materials, and the easy means to save them out to a custom library, add your own external maps and so on...one of the most widely used roof cladding sets in NZ is corrugated steel sheet roofing, tray / trough sections as well - these are used on houses, factories, warehouses, retirement facilities, schools and so on all over the country , every year and yet I cannot even have access to make what I need in my design / production platform and there isn't anything in the library for this.
Similarly, a good number of horizontal cladding types and profiles are widely used - once again, there seems to be nothing suitable for easy use / edits for claddings to suit my local market, and as above we do not seem to have the latitude to make custom materials let alone store them externally.

I cannot understand how the local NZ master distributors can look us in the eye.

It is not at all any good and will make a worthy subject at the inaugural Wellington Revit User Group meeting tomorrow night.


Before I get censored for a couple of rants in the last couple of days, for politics, I feel very unhappy that such great work on this release, that is making Revit better every year, is at the same time really hard to accept the adversarial nature of this mental ray integration with Materials editing restrictions and lack of easy power to save things out.

How about some explanation from the factory or anyone who can tell me that it will be all right ?

This seems to be a really restrictive move and I imagine that in future weeks as we have more time to absorb the wonderful new features and tool sets, this problem will become widely hated and I would ask now that it is patched fast so we can edit and add new materials and save them out easily.

(BTW - unrelated maybe, but thanks for the very good UI tool for editing dimensions / overrides it is easy to use and helpful).
Would like to hear more from anyone who feels this way or has a different perspective on this problem.

thanks
trombe

iru69 thank you...i will try.
I try to link some of shaders(simbiont/mental especially...nice archi.shaders) by using spider-classes and c#module ... as soon as possible i post it.
and when it will be work, no needs in Max

Excellent write-up thanks for taking the time to do this.

Quote:

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Originally Posted by spirekin

iru69 thank you...i will try.
I try to link some of shaders(simbiont/mental especially...nice archi.shaders) by using spider-classes and c#module ... as soon as possible i post it.
and when it will be work, no needs in Max

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As posted elsewhere - you cannot add shaders to the MR in Revit at this time.

All I was expecting with this release, was to see less "workaround" methods....
Thank God for giving us standalone renderers...

I nominate this one for Revit Workaround of the Year (2009)! Well thought out, cheers. I will propose implementing it to my clients.

Quote:

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Originally Posted by iru69

IN PRACTICE

1. You're working on a project.
a. You have a material named "Door".
b. It's assigned one of the built-in Library MR Materials: "Wood Maple".
c. You would like to change the MR Material to a custom MR Material in your custom Material Project library: "Wood Fir". (btw, have these people ever heard of a Fir tree?)

2. You open up your custom "Wood Fir" Material Project from your custom material library.
a. You see that the material name in the material settings is named "Wood Fir".
b. You rename "Wood Fir" to "Door".

3. You flip back to your project.
a. You transfer the material from the "Wood Fir" Material Project to your project.
b. It asks you if you want to overwrite you existing materials (including "Door").
c. You select "Yes".
d. Your door's MR Material is switched from "Wood Maple" to "Wood Fir".

Further Notes:
a. You can keep only a single material in a Material Project file, or you can keep a group of related materials (e.g. concrete materials), or you can keep all your custom materials in a single Material Project file.

b. You can also use essentially the same concept by keeping your materials in a Material Family template. Families are a bit smaller and more portable and it's relatively easy to add new materials to a project just by loading in a Material Family file (I've attached an example Material Family template).

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