System Units

[GALACTUS]

Hi Everybody (hi doctor nick )

So I was thinking, Of all the Arch viz people what seems to be the best scale to work in and do you encounter any problems working outside your comfort zone?

I for one like working in millimeters unless the site is very large in which case I switch to meters. I have had some problems in the past with Vue regarding scale and I have read that some renderers work better in centimeters for instance.

What are your thoughts, problems and observations on the Max scale thingy.

[Pixelab]

Centimeters for system unit, but general units for display (to modify the values easier) I did never encount problems in my scenes, but had some when importing from other programs (sketchup or autocad) where the models were drawn in meters or millimeters...

[Candelero]

I personally work in centimeters (for interiors). For EXT, if it is huge, may switch to meters.

Best regards,
nikki Candelero

[GALACTUS]

So any reason why you guys work in centimeters as opposed to millimeters or feet etc? or is it down to the system of measurement your used to using in your respective daily lives.

Does VRay have any scale preference when doing its calc internally for things like lights for instance and the way their size and power is computed or irradiance map calculations.

I know does not matter.......or does it

[thablanch]

Whatever the base plans are. Way easier for future import if ever the CAD layout changes.

Yep, one thing I learned quite fast... Never change the baseplan emplacement, never change the base plan units.

[Neilg]

I always change the units and rescale the cad, I trust my judgement more than their consistency

I'm a millimetres man. Mainly because I dont like having to use 0.~ in my units, I like to stick to whole numbers.

[vlado]

The display units do not matter for V-Ray, however it does matter what the actual numbers are when converted to generic units. In general V-Ray works reliably with numbers on the scale from about 0.001 to 10000, that is, about 7 significant digits - this is more or less the maximum capacity of the single-precision floating pointing numbers used to represent vertex positions in 3d space. Of course, these are not absolute limits - smaller or larger numbers will mostly work fine, but the chance for artifacts in the rendering due to precision loss becomes higher.

Also, one thing that you should avoid is to have detailed objects far away from the origin.

Best regards,
Vlado

[GALACTUS]

Am with cubicleganster, dont like me zero's before me decimal point.

0.001 to 10000 is quite a large range which is great.

I would scale in cad before bringing into max as its easier for me.

Avoiding detailed objects far from origin is hard cos we leave the cad info as the architects have sent it, the position that is. This is better for us, as it saves us having to transform data sent everytime there is a change. As a result sometimes the damned structure is miles away from the origin. I think some architects have their 0,0,0 set to the damned north pole, I mean when you get coordinates of 324235285425425.04574, etc (slight exarggeration)

My was that a rant, sorry damned architects and forever changing stuff, opps sorry again

[ShaunDon]

We're in the states, so everything we do is in imperial. As a rule we stick to inches. All our content is created in inches, so we keep those units for consistency in all our jobs rather than have to have max scale back and forth. Also wreaks havoc to scale rigged bipeds and such. So I say do whatever is going to cause you the fewest headaches.

Shaun

[Dynedain]

We use CM as our "system unit" for better compatibility with VRay, but use Feet w/ Decimal Inches for our display units.

[paulison]

millimetres for us. We would get shot at uni in australia (well for architecture anyway) for using anything else other than 'mm' so i guess its just stuck.

I've always thought we have a bit of a scaling issue coming from archicad but when i look at my display units, everything looks to scale... Like today we had some spotlights with inverse square decay which seemed to decay waaay too quickly to the point where the scene wasnt receiving any light

I don't understand why max has generic units...what are they?. how big is 1 generic unit?. I've always ignored generic units thinking that the display units was correct...am I wrong?. I've stuck with our method for importing scenes but it gets confusing sometimes because maybe there is a better way?

[tct70]

mm all the way. The UK went metric (except on building sites) over 30 years ago, so all architectural drawings are in mm.