best format for car cad data into max and vray?

[joconnell]

Heya Folks,

I'm going to be doing a few shots on a film soon with a car crash in it. They've gotten two cars from the manufacturers so they're definitely on side, so I'm going to try and get some cad plans of the car rather than getting it scanned which won't get me any of the headlight detail. I've never gotten files from a car maker before though, so has anyone got any advice on what the best format to get data in would be considering it'll be put through max and vray?

Is it a case of using power translators and iges files with the built in importer or is there a far better solution? The Body and suspension will no doubt end up getting rebuilt as it'll need to be crashed and deformed but it'd be great to start building that from the original shape.

Cheers for any tips or thoughts!

John

[Donald2B]

Well, I would go for trying to get STP files and using the new importer in Max2016. It has been THE BEST solution I have used to date, so about 5 years of importing engineering data.

The problem will be the export quality from client/engineering program. Some programs export MUCH better than others. So quality of the export may vary widely. I use an engineering program to evaluate the data before importing into MAX. Some files are bad even before importing them. To save time I request new files and try again.

If you don't have access to Max 2016, I would ask for SAT files and use the default Max importer. Those tend to import the best in Max 2014, better than IGES and STP files. Some parts may not come in clean and may require using a different format like IGES or STP files. Since I have an engineering program in house I can export any file type I need to get all the parts into Max cleanly. I would just write a script to import the files, turn off backface culling, convert to editable Mesh and then add vertex weld modifier or something similar to weld part surfaces together.

I have tried all of the other importers with varying levels of success. Ultimately it boils down to the quality of the export from the client. I know I kind of talked in circles, but I hope a little of this helps.

[Wilyman]

Hi John,

It all depends on who the manufacturers are. Pretty much all the big OEMs these days have somebody that prepares all their CAD data into polies for them, and then sends that out to all the suppliers that need it.
In my experience, it's usually RTT, or 3DExcite as they're now known, and they usually send out Maya files.

If you do get CAD data, I'd probably clean it up in something like Alias or Rhino, and then tessellate it in Showcase or VRed.
The body objects or PowerTranslators objects in Max are good, but they do need to get tessellated at render time, so they can slow that down a bit.

One thing to note, is that if you do get CAD data, the chances are it'll be engineering data, and so it'll have B surfaces, which are the back surfaces of all the components.
You'll want them on the glass and anything transparent, but for everything else, they'll just be taking up memory.
Getting a car ready for rendering can be a pretty big job, so hopefully they'll already have a poly model.

Cheers,

John

[joconnell]

Much appreciated folks - Step seems like a good base since we'll have max 2016, Rhino or showcase would likely be options too within the budget. We've requested some step files from the manufacturer, lets see what they come back with.

Thanks for the effort and insight.

[Morne]

If you've not worked with CAD engineering data before, be prepared to get a bit of a shock..... and lots of work to clean it up for your needs

[kosso_olli]

In my experience, it's usually RTT, or 3DExcite as they're now known, and they usually send out Maya files

Oh dear, worst case scenario
In the last months, I have been getting a lot of crap from that company.

[jasonhuang1115]

Hey John,

You got the exterior part scanned and for the headlight maybe can try using VRED (30 day full trial) to tessellate and export FBX. We have been exporting data from VRED to Maya this way without much trouble.

[Mokiki]

Oh dear, worst case scenario
In the last months, I have been gotten a lot of crap from that company.

Yeah most of the files you get from RTT are just horrible. But I have the feeling they're doing it on purpose, since they always seem salty when they don't handle the cg side of things. >.>

@Donald2B

Thanks for the info. Didn't know that thew importer in 2016 was any good.

[thablanch]

Max also imports native Catia files, so if the car manufacturer has them, so no transfer to step or iges loss.
Previous to Max2016 imports as BodyObject. Extra conversion work is needed, but feasible.

[tom182]

hmm, this is interesting as most car manufactures will model up in Catia/iCemsurf/solidworks (Or they used to) - if they are kosher giving a native format then it should be at its cleanest but as mentioned you may have to work it through a middle prog like Rhino, i did it a few years back (Pro-E> Rhino>Max), hopefully its a simpler methods now, keep us posted