All posts related to V2
User avatar
By Half Life
#338460
UV's do not change the scale of the Geometry... the easiest way I can explain it is the geometry exists in a coordinate system of XYZ and every vertex/point has a particular coordinate within a larger XYZ world -- so the concept of scale for geometry is really only a concept of how big the faces that are defined by those vertex/points are in relation to the world system.

2D graphics also have a coordinate system which is XY, but because those mean something specific in the 3D world system the program needs to use different letters to assign to the 2D coordinates the letters UV are it.

So basically what it amounts to is the geometry can have any "scale" and the UVs can have any "scale" and the tiling can have any "scale"... so to be able to have a frame of reference for scale and tiling at least 2 of them must be normalized.

We already know that your geometry should be correct in scale and we know what that scale is and it is equal to 1m =1m, or if you prefer 1cm=1cm... it's a 1 to 1 ratio with real world essentially (but may not be if you are using scaled components as they remember their transformations from their original size).

The problem here as I see it is you seem to not have your UV's normalized and you also seem to have your tiling not normalized -- one of them needs to be 1 to 1 (square as you say) to be able to accurately scale the other.

From where you are now I would say the simplest thing would be the set the tiling in MXED to 1 and 1 relative and scale the UV's until you reach the correct size... since you have a dedicated UV editor this should be possible.

However, My preference would be to set the UV's to 1m x 1m and set the tiling in MXED to meters and use the correct size (.0676m x .0298m) there -- the reason you use one meter by one meter UV's is because the tiling in MXED is based on that same meter scale, the UV's being square is a good thing because is gives you a constant coordinate system that is not distorted to tile your 2D graphic on.

1m = 100cm = 1000mm so the fact that you are wanting to set your tiling in mm is not problem at all as the conversion is easily accomplished... and Maxwell can easily accommodate your desired precision by simply typing it as .0676m x .0298m.

IF your UV's are in fact .0676m x .0676m then you are correct your current tiling settings should work -- however since you are only assuming that they are they very well may not be unless you explicitly set them that way, because as I said earlier they can be any scale or aspect ratio and you won't know what it is unless you set them explicitly.

I don't use your UV editor so I don't know the particulars of how it works -- but if the setting of displacement size is giving wrong results then one (or more) of the 3 variables (geometry, UV, tiling) is the most likely culprit... based on the feedback you are giving here it is either geometry or UV scale (or both) is not correct.

The fastest way to know if your geometry is out of scale is to normalize the UV's (1m x 1m) and set the tiling in meters to .0676m x .0298m -- if the results are wrong then your geometry is not to scale because the other 2 variables are accounted for.

If all 3 variables are to real world scale then displacement height in cm (mm) should work perfectly.

Best,
Jason.
User avatar
By Burnum
#338496
Thanks for fighting through this with me.

I'm going to link my test model so you can also see it if you wish. At the moment I have no way of checking the scale of the UV system, other than to say i know for a fact it is square. UVlayout is very powerful, but it's primary focus is video games and organics, not engineering. the developer however is VERY responsive and even added a feature at my request just for this project! :) I will talk with him and see if any of the setting a scale to the UV system makes sense to maybe add to his software. as it stands nobody else cares, they are painting monsters and people mostly, and without any regard to true scale.

I'm hearing what you are saying, however I have another issue I don't think you picked up. The depth box on my system at least will not accept numbers smaller than one decimal place... my depth is .21844cm all I get to enter is 0.2, and in the tiling of the UVs I can only enter 0.067... when working with such small things, that amount of rounding makes a huge difference.

My second issue now makes me think the SketchUP 8 Plugin has a bug. things exported to MXS from there come into Studio at .025 scale... vs importing an OBJ also exported from SketchUP 8.
User avatar
By Half Life
#338499
You can increase the amount of decimal precision in Studio by right clicking the field of interest and selecting decimal precision -- in the Sketchup Plugin you can do the same via the context button next to each field.

That potential bug should definitely be posted down in the Sketchup forum to see what JD thinks.

BTW, I'm only trying to help -- I'm far from the UV master myself I'm just going by my experiences working with Maxwell and "Realscale"/"normalized" UV's and setting up Maxwell materials to tile at the proper scale within that system in reference to displacement. I've had my fair share of UV shenanigans working with Sketchup and Studio trying to get a process for easily repeatable results but as I say I have no experience with your particular software (although I have seen it before) it looks like a very capable software for organics and the developer certainly knows more about UV's than I ever will.

Best,
Jason.
User avatar
By Burnum
#338501
I can't find any way to measure this model... SketchUp lets me export OBJ, but I can't re import it to make sure it didn't change...
User avatar
By Burnum
#338502
WOOO! right click to choose precision, good one to know! :)

I'm always felt Maxwell would do well to have a measuring tape tool... you could do things like measure from camera to several points, or check dimensions of an object for texturing. etc...
User avatar
By Half Life
#338504
I bring in your OBJ into Sketchup with this plugin: http://forums.sketchucation.com/viewtop ... 90#p172790 and the units set to meters the radius of the cylinder is .3m (for a circumference of 1.88m) which is very close to what I calculated it would need to be to need a displacement value of 7.7cm to reach the target look you wanted (my calculated radius was 0.38m BTW).

I think the OBJ file is coming into Maxwell with the scale set to meters and that is the source of the issue...

BTW what units were you using when you created this geometry? (I'm guessing feet or inches...)

Best,
Jason.
User avatar
By Half Life
#338506
The easiest way to get what you want seems to be to scale the OBJ down to .125 (.127008 to be precise) after import into Studio.

BTW you can set the grid in Studio to any size and it shows up is all the orthographic camera views -- which can often serve as a measuring system.

Best,
Jason.
User avatar
By Burnum
#338508
I feel like a moron at the moment... I built my test model back in January when I was hunting for a tool to get usable UVs on it... I totally forgot that I had only estimated the outside diameter at that point... The model I sent you has a diameter of 0.6" in the original SU file... (radius .3")

I do work in inches and feet, and then convert to metric when I need to in Maxwell. So basically (aside from my face plant oops of not using a tube with the correct dimensions), when I exported it to an OBJ, it got interpreted as .6 meters OD rather than keeping it's true scale, or becoming 1.524cm OD...

Thank you for your help! :) I just don't get to do this stuff often enough yet...
User avatar
By Burnum
#338511
I'm going to have to get the plugin to import back to SU.

I also dug around and figured out that my OBJ export settings had it set to Model Units rather than Inches!
User avatar
By Burnum
#338862
I STILL CAN'T GET THIS TO WORK!...
User avatar
By Burnum
#338876
here is the state of things so far...

First it seems Maxwell imports as Meters, period. So when I export as meters it seemed to come in at 1:1 scale yet fits to the Sketchup plug-in exported parts with the scale of 0.02540. (i'm not messing with UVs on those, so I created my master document from there.)

You suggested I use MXED UV tiling set to meters and use the correct size (.0676m x .0298m) there, but if the UVs exactly fit the circumference of the tube, how can using meters rather than relative work? I tried this, and things got so small you could not hardly see anything... I think to do it that way I would need a way of normalizing my values for the tiling to 1 meter...???

I'm still convinced that everything would be perfect if only Maxwell let us set the depth based on the U or V tile scale rather than on some random % of the biggest bounding box edge size. That makes no sense to me...
User avatar
By Burnum
#338877
I think ultimately I need to forget the real scale of my model since i'm forcing the UVs to fit the Circumference of the model it will be 1m no matter what if I set things to meters. so assuming that, i think this is what I need to do.... going to test...
  • Circumference (texture width) 1004px = 1m
    texture height is 442px = 0.44024m
    depth is (the hard one) .0021844m (based on .06759) = 3.23195cm (relative to 1m)
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