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munkittrick

Quick question about scene scaling...

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 Hi all, I'm a 8 year vet of C4D use in a professional environment, so I feel a bit awkward in asking this....but here goes.

 I have a hard surface building that was created in Blender with a character created in zBrush. Both files were exported to OBJ for flexibility. When I import them, I can change the hard surface building scale to meet the C4D scene scale....but upon import the zBrush object, the scale is way off....even though I've imported the scene with the proper scale.

IE, the building must have been created in MM instead of inches, so I have to scale it up to fit the scene properly....but the polygons on that object EVEN if they are the same physical size as an object created within C4D, the polygon faces show up as dramatically different measurements. How do I import an OBJ scene into a C4D scene and make the polygons, NOT just the scene scale enlarge without literally scaling everything in the interface?

MUCH APPRECIATED!!!!

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I read what you wrote several times and still don't really get what the problems is.  I get it's a scale issue, but not much more and some terms you probably are using wrong.  You say " NOT just the scene scale enlarge without literally scaling everything in the interface? "  Interface includes the icons in C4D.  Anything in the scene is not the interface.  You should not change the interface scale in C4D any scale purposes in the scene.  There is also mention of different sizes of polygon faces which makes it sound like some of the polygons in the model is one size and all the others in the same .obj imported are a different size.  If that is the case it was not exported right or maybe C4D is doing something really crazy on import.  I've had some strange imports where polys are missing or all pieced together wrong.  Import the same file to another program and it works great.  If that is the case exporting to another format might be better.

 

For scale in C4D it's a little hard because if you are too small it will glitch a little and be hard to work with.  If it's too big it will start to have polys missing in the viewport.  The scene then needs to fit somewhere in between so it's in the box that is the C4D workspace.

 

To help make sure it's to scale I like to make a box to the dimension the object I'm importing should be.  Importing from any program can have drastically different scale even if they are put in the same .obj format.  This makes having the box to the right scale even more important.  If it does not import to the right scale you can manually scale it right or try re-importing with different settings on the scale when imported.

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  • I guess that it was a little complicated to understand, but here's the basics simplified.

     Imagine that you've created the model of a penny in zBrush and another in Blender. When they are imported into C4D, the pennies appear to be identical in size, but one of the pennies is 1,000 inches in diameter and the other identically sized in the viewport is .00125 inches in diameter. If I select the penny with the higher number measurement, I can easily move it around as per normal, but if I select the second penny and try to move it even extremely slightly....the thing goes into infinity and is no longer visible.

    1.) I was supplied with a building that I will be using to replace another structure in a live action shot. That building was modeled in Blender with INCHES as the relative measurement that was exported to an OBJ. (I misspoke earlier. The building is in inches, and the character is in mm)

    2.) I have another OBJ created in zBrush that contains a mesh that was created with millimeters and re-topologized for animation.

    3.) BOTH of those items will be motion tracked and modified in C4D and combined for compositing with After Effects at a later time. The C4D scene is using cm due to the relative size for numerous composite effects (fire, shattering glass and so on).

    4.) It begins to get complicated when I try to import the building. Being that it was created in mm, it has always been a very simple "scale-to-fit" solution to match up the frame size. When I import the obj building model, it is TINY...so, I cluster all of the child objects and scale numerically by simply multiplying the polys of the model to fit the scene. After I scale the building up and select the polygon that I want to modify, (in reality a two story house roughly 25 feet tall) the object's polygon size is 0.0129in....even AFTER scaling. In fact, I split the main panel and copied just that polygon face and it remained very, very small when compared to a primitive cube which measured at 6,200cm. Side by side they are identical in size....but the imported object looks and acts like a huge object. I can select that split polygon and even the tiniest movement of my mouse shoots that object WAY out of the scene whereas the editable primitive cube moves in infinitesimally small increments.

    5.) Here's where everything goes off the rails. When I import the zBrush character that was exported to an OBJ file into that same scene for rigging in C4d, it shows the model to be over 1,200 FEET tall, and scaling within the interface doesn't change the measurements of ANY polygons, even thought I'm scaling the thing down to about 1/16th of it's original size.

     

     Basically, I'm importing everything as I always have, I've verified the scene size and format before and after importing the OBJ objects. I'm beginning to think that there was some kind of issue upon export from either Blender or zBrush.  I'm just going to have to play it by ear and see if I can get new files from the modelers and start over.

    Thanks so much for your time.

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    There is a reset scale command.  There if a funny thing in c4d where the scale of the axis can be different and cause weird stuff to happen.

    I think there are other ways to scale in c4d, but I forget all of them.  One of those other scales in c4d could be messing it up because there are like 3 places to change the scale for a single object.

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    Have a look at all the matrices of the object and its parents in the attribute manager, especially the scale factor. I have the feeling that some scaling has been done in the Object mode instead of the Model mode, and now a scale factor is <>1.000.

    This can lead to weird measurements and weird behavior.

     

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  • Yep. The creator had resized a proxy mesh for animation as a deformer for the high-poly mesh, scaled the two separately...and then...he hid it in zBrush. All better now! Thanks!

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