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View Full Version : Modeling In "Real World Units"

 BUZZFX10-20-2007, 05:34 PMSo as far as I can tell working in "Real World Units" does not work in Cinema 4D. Try creating a 6 foot human and then try zooming in. It doesn't let you zoom in more than 1x or 2x unless I'm missing something. Why doesn't Maxon make the zoom fit real world units so when I create a 6 foot figure I can still zoom in a lot, but it doesn't seem to work that way. I need to make a building in C4D for another application and if I make it in "real world units" in C4D it is very small and I can only zoom in 1x or 2x and then I'm out of zoom-in's if you know what I mean. It's harder to judge the size of elements when you have to multiply them by 10 or 100 units. If my wall is 8' feet tall (2.4384 M) then why can't I build it this size in C4D? But the default cube is an unrealistic 200 m x 200 m in size. If I build the walls 100x their actual size. So instead of having a wall an actual real world unit size of 8' feet tall (2.4384 M) I guess I'll have to build it 800 feet tall or (243.84 M) tall so I still have room zoom in and add detail like window frames etc? IMO not working in "real world units" just makes the calculations more difficult to figure out. I can easily visualize things in "real world units" and so I can build them quicker if I can work that way. An average person is 6 feet tall or 1.8288 M, but to have to multiply everything by 100 just takes a little longer to figure out. Tell me how you work? What unit of measure? (Feet/Meters etc.) And at what size do you create your models? Thanks
abdelouahabb
10-20-2007, 07:59 PM
hi
1st why not setting the cinema 4d units to centimetres (working with inch, 1inch=2.54 cintimetres) or work idrectly with inches!
2nd, if you want to zoom to and area you must select it! so if you want to see the foot just select the polygons!
then, if you want a real control around your work, make a camera, this camera should not be used as a render camera, then play with its parametres, you'll get what you need, and never forget the S shortcut on your keyboard, just select and object or area and then tape S the view will be zoomed to your object!
hope this help :thumbsup:

Per-Anders
10-20-2007, 08:16 PM
Change what units you set Cinema to use then. All it changes is the way the unit is displayed, whether it has ft, m, cm, mm etc after the number, not the actual unit itself. Cinema units themselves are not "realworld", they're just an arbitrary value that you can assign whatever scale you want to, this has been discussed many times before.

vid2k2
10-20-2007, 08:40 PM

Say you need to build an iPhone.
Get the front pic as reference on a plane.
Size the plane to the material image.
You know the size is say ... 3"x4.5"
Drop in a cube primitive and set the divisions to inches or fractions of inches.
Make the cube editable and use this as a scale to model all the components.

BUZZFX
10-21-2007, 08:13 AM
Thanks for all of your replies.

I have set my C4D units of measure to Meters. See my image. The tiny cube is 1.8288 Meters or 6 Feet Tall (The height of an average male). If I want to build my character at actual (Real World) size then I need to zoom into this "Tiny" cube and add arms,eyes, mouth etc. but it doesn't work because C4D won't let me zoom in that small.

All I'm saying is it's a pain not being able to work in "Real World Scale" I have to multiply the actual height (1.8288 Meters) by 10 or 100 so I am able to zoom in on the geometry to work on it. It would be nice to make my figure the actual size and still be able to zoom-in to work on it.

Maybe C4D will add this feature in the future. :)

Thanks

Per-Anders
10-21-2007, 08:23 AM
I think you're maybe not following. The units only change the actual ending. So use cm or mm instead. End of problem, you are then working in real world units/scale and no longer have to multiply anything because Cinema by simply changing the unit has multiplied up the base unit for you.

Bob3D
10-21-2007, 11:18 AM
I don't bother with units, it's just some text in the value boxes to get in the way imo.

nycL45
10-21-2007, 12:37 PM
...and never forget the S shortcut on your keyboard, just select and object or area and then tape S the view will be zoomed to your object!
hope this help :thumbsup:

"S"? How about that, "S" works the same as "O"! Note: the axis has to be on the objective or near it to avoid frustration.

nycL45
10-21-2007, 01:59 PM
I have 1/16" tile joints (model scale 1/4"=1'0") and threaded screws (model scale 1:1) I modeled on a lamp that I zoom in to adjust and it fills a good bit of my MacBkP screen. So, I am not sure why you can't zoom in. (It should be noted that C4D becomes unreliable when working with extremely small objects because of floating point/accuracy issues. This is for archviz something that needs to be fixed if possible. Many here will recommend enlarging, as you and others have mentioned, to avoid this issue. And then rescaling is necessary for Vray's IES lights.)

Rantin Al
10-21-2007, 03:39 PM
If you need to work in real world units, pick an appropriate base unit.

To match your example of the average height of a man, use cm instead of metres.

By changing the unit to metres, and using the same cubes, the same scene could represent a couple of city blocks. Only the texturing (and maybe a bit of extra modeling detail :)) will decide what it will eventually be.

HTH, Alan.

abdelouahabb
10-21-2007, 04:58 PM
Note: the axis has to be on the objective or near it to avoid frustration. just use center axis with r10 it's integred, if you're working with previous releases use the plugin!, hope this is useful :thumbsup:

Tzrnutt
10-21-2007, 07:52 PM
Am I the only one who's never had C4D "run out of zoom" before??

Mine just keeps on going... :shrug:

nycL45
10-21-2007, 08:03 PM
just use center axis with r10 it's integred, if you're working with previous releases use the plugin!, hope this is useful :thumbsup:

Yep. I keep two, yes 2, buttons for center axis - top and left side. I use them so often, the labels on the buttons are showing wear and tear. ;)

PresNevins
10-22-2007, 01:24 AM
One of C4D's strengths is in its interface "comfiness" so I think this is an important topic for discussion. Workarounds are fine in the short term, but if we can get clearer on what exactly some of us are looking for, we may run across a method that makes it easier for Maxon to eventually implement a beefed-up units system that's comfortable for everybody.

I have a scene that I set my units to inches to match with the existing plans, but I kept running up against the granularity of the zoom making editing cumbersome. When I read somewhere that the hair and cloth simulations work best at larger scales than this anyway, I gave up on working purely with inches and multiplied everything by (a fairly arbitrary) 15, which put everything at a world size that felt more "normal."

If C4D is unable to comfortably work with tiny fractions of its arbitrary unit, then what about having it display a different unit than what it's internally using? Like having a Basic Units option of "Inches (Optimized for small work)" where one displayed inch would internally be 100 or 1000 C4D units or something? That would keep unneeded complexity away from the user, while allowing C4D to smoothly work with numbers that the user thinks are tiny. Then when you export to different formats, do whatever unit conversions are needed to have it transfer at the size the user thinks they're using.

Pres

nycL45
10-22-2007, 11:11 AM
C4D does that sort of thing with the Import/Export "correction" factor (Preferences) for different (CAD, etc.) software. Following your suggestion, checkboxes for enlargement multipliers could be on the next line and everything created and imported would be enlarged by the preset or custom multiplier the user checks. It sounds simple but my bet is, it isn't. But, it may be an easier solution than what would be required for the floating point matter.

The only time I have problems with zoom is when the Editor camera gets bogged down and the Focus/Zoom readout indicates 20,000 or whatever. That glitch is corrected using the Frame Default from the viewport Edit menu.

ernia
10-22-2007, 02:41 PM
I like to think of C4D scale/unit issues to be more analogous to a potter and his wheel or a carburetor's mix ratio.

If you picture yourself as a potter sitting at his wheel (you know--the things with a spinning disk you have to kick while you are working the clay), the lump of clay you smash down on that disk can only be so big or so small. Too big and the thing might fly apart or cave-in and the tools you apply to the moving clay may not be strong enough to withstand the force; too small and you can't get in there to effectively shape your clay and work with it. That's why you see most pots' sizes falling within a comfortable range. There is a "sweet spot" where everything seems to work together.

Same with C4D. It seems to be calibrated to comfortably and optimally work with scenes within a general size range. Too big or too small and the lighting starts to have problems, the movements of points and polys become unwieldy, and calculations get less accurate. Therefore, it doesn't matter how big units are because it's all proportional not actual. C4D likes to see something about "this" big in proportion or relation to tool efficiencies, and it doesn't matter how you break those units down or how big you make them.

For the car nuts out there, same thing with the carburetor's fuel mixture: too lean and she starts to gasp; too rich and she starts to choke. Get the right mixture and she starts to purrrrrrr.

Some engineer somewhere had to make a decision on where to calibrate this 3D application. Whether it's Newton or Ford, this is what we have to work with.

As a tip, I've found that converting or working with points (printer's points--72 points per inch) allows the units to come into C4D unchanged and "calibrated". So if you are in Illustrator your 84cm cadenza will come into C4D at 84cm if your C4D units are set to cm, or 84m if set to meters, or . . . but the "lump of clay" is about the right size for C4D. Same with Rhino: export to printer points and your buildings come in about the "right" size for C4D. This way you can add a 14cm drawer to the cadenza or a 40ft retaining wall in C4D with no problem--but remember these aren't actual measurements in the real world.

hth,
ernia

BUZZFX
10-22-2007, 06:02 PM
Per-Anders,
You're probably right, I don't think I was following but this makes sense, I will try cm or mm and see how it goes. Thanks : )

Bob3D,
Thanls! : )

nycL45,
Thanks! : )

Alan,
I will try cm and see how it goes. Thanks : )

abdelouahabb,
Thanks! for the tip : )

Mike,
Maybe!. LOL Count yourself lucky! Thanks : )

PresNevins,
Thanks for the discussion! : )

ernia,
Thanks! Great example with the potter's clay. Thanks! : )

nycL45
10-22-2007, 09:19 PM
Hi Paint Guy. I just wanted to add a couple of Srek comments regarding scale from an earlier thread:

1. "As a rule of thumb the default world grid should be usefull to you.
If your scene fits roughly in it then it's ok. Diverting from this by a factor of 10 is no big deal, but a factor of 100 or more might become problematic."

2. "Back on topic, the scale in CINEMA usualy only is a problem if you exceed the size of the primitives by several orders of magnitude in either direction. Most of the functions in CINEMA 4D that need scene size related parameters to work are preset to values that will work in this scale. This includes Hair, Dynamics, Cloth, S&T and much more.

The main reason why there are problems if you work with extreme sizes is the limited precision of the floating point values used in CINEMA. There is no way around this problem without increasing general calculation times (animation ,rendering whatever) by several orders of magnitude.
At the same time this is also a reason (one of several) why Graphics cards are not used to render, they have a much smaller floating point precision then common CPUs. Thus they are faster, but also more limited."

Rantin Al
10-22-2007, 10:18 PM
I posted a tip on setting up relative scale between Illustrator and Cinema over at the Cafe. (http://www.c4dcafe.com/ipb/index.php?showtopic=26542)

If there is some way of getting CAD files into Illustrator, it should be a simple matter of adapting the cad file to match a couple of perimeter guides.

If it is an image line-art plan, it is simply a case of place and scale to the guides and create the splines as detailed as required.

BTW, I haven't done any real archicad work so this might not be the pro-way of doing it, but for simpler spline objects which are to be used as modeling guides, I think it is handy method.

Cheers, Alan.

designbytes
10-22-2007, 10:23 PM
not sure where I am going with this....and don't mean to hijack the thread....

I've read this and the linked thread and am trying to get my mind around it (duh!) and any relevance it has on planned model detail (or lack of) within a certain scene. I am trying to figure out

let's say I have three main objects whose overall length ratio (each with their respective tiny bits) of:

6:60:500

the "6" certainly has tiny parts of "0.6" and maybe even "0.06"....

if the "6" interacts with the "60" and "500" objects, where is the trade-off on when I should have "more detailed" and "less detailed" version of each model? ...and if the camera moves from close to the "6" and backs off to see all of the "500"?

What rule of thumb do folks use to make that decision? any tips/tricks?

abdelouahabb
10-22-2007, 11:09 PM
not sure where I am going with this....and don't mean to hijack the thread....

I've read this and the linked thread and am trying to get my mind around it (duh!) and any relevance it has on planned model detail (or lack of) within a certain scene. I am trying to figure out

let's say I have three main objects whose overall length ratio (each with their respective tiny bits) of:

6:60:500

the "6" certainly has tiny parts of "0.6" and maybe even "0.06"....

if the "6" interacts with the "60" and "500" objects, where is the trade-off on when I should have "more detailed" and "less detailed" version of each model? ...and if the camera moves from close to the "6" and backs off to see all of the "500"?

What rule of thumb do folks use to make that decision? any tips/tricks?

a tip but i think you should forget it ;-)
use a camera with a null object in the target tag, animate the null object so i think it will show all objects.....:hmm:
or....
in the target data you can see that you can animate it, so just play with zoom values and replace objects in the target data...so like this the camera data will be relative to the objects.;)

PresNevins
10-24-2007, 07:06 AM
Leonard and Al, thanks for the thread links! They were very useful indeed.

Pres

nycL45
10-24-2007, 12:22 PM