[kraemerJK]

Since I am into archviz the "real scale" option for materials sounds very fascinating for me. I just can´t get it to work. But maybe it is me, because after searching through the forum I found nobody else reporting problems.

Here goes : I have a material with a texture map. The Map equals 3 x 35 cm in reality. So I activated real scale in the material editor, entered 0,03 and 0,35 for x and y and used the standard material scene to check it. The Sphere in this scene is said to be 7.46 cm in diameter. So my material should be mapped twice.

What I see is a heavily mapped version, very small texture.

I then changed it to .3 and 3.5 for x and y. THEN it is the right scale. What I don´t understand is : It says

real scale (m)

and in the manual it says :

For example if you want to create a material with 25 cm tiles, check the Real Scale Box, and set the tiling to both X and Y axis to 0.25.

But my settings indicate that it is not in meters, but in decimeters. Is it me or the real scale function ??

[Mihai]

I think it depends also what size the projector is. It should be set to 1, as in 1 meter. I think though there are some issues still with real world scale. It seems to behave correctly with cubic projections. In case you have imported the object with uv's already, it might be using that projector and things mess up. However if you make a new projector and set it scale to 1, things should work ok. Speculating a bit

Btw, if you can, delete your post here and post it in the maxwell forum instead.

[kraemerJK]

I thought real scale was MXM related ? No ?
Well anyway, I can only speculate myself, somehow I got it to work, except that it doesn´t follow my logic. Since I do not use studio a lot but use the c4d plugin, there might be some trouble ahead when I switch from the standard material scene to using the mxm in c4d.....

[Tim Ellis]

I use real world scale all the time.


I open the texture map in Photoshop. Open the Image>Canvas size dialogue and change from pixels to cm.

For a 400x523 pixel image, this gives me 14.11x18.45 cm image.

Enter this into the texture dialogue in MXED once ticked the real scale box, as 0.14x0.18.

This gives me correct mapping for objects that are to scale, even if I use my own UV projectors (Locked).

Hope this helps.

Tim.

[lllab]

hi tim,

based on what dpi setting do you get your cm scale in psd?

thanks cheers
stefan

[EONA]

How about a grid in the MXM image loader that can be switched on and off, a setting that you can change this grid to whatever measurement your image is mm cm m km. the grid can be scaled up or down (so you can change the grid size to fit whatever you know or believe your image should be) So when you use your projector in the default 1 scale it will represent the correct scale you created in the MXM unless you want ....lets say object two to have the same texture but it's to be twice the size and therefore you would set its projector to be 2x
I see Tim's method working in a fashion but lets face it you could have two images of 800x 600 one of a mountain range representing several KM and another of a zoomed in wood grain representing a few cm.

[Tim Ellis]

hi tim,

based on what dpi setting do you get your cm scale in psd?

thanks cheers
stefan

Whatever the texture map is preset to. For my own textures 300dpi from memory, but for all others pre-made by whoever, then I use their dpi.

From memory it's usually 72dpi. Could this be bad practice on my part, or does this seem correct to you?

Tim.

[lllab]

very wierd tim, i dont get it???

never heard a texture can have dpis? how you would measure that. texture scale is in space. i thought a texture can have meters or centimeters or feet etc...you need the info of course- with arroway p.e. you know how big the textured part is (somehting like 9x9m).

but how can i have that in maxwell. i can press the checker button real scale but it seems not to do that. i still have to manulally set 9x9 m uvw in my host app.

so i dont get the real-scale feature....

maybe someone of the programmers could explain how they meant it?
thanks & cheers
stefan

[Fernando Tella]

Rescue me from my ignorance. What is Real Scale option supposed to do? Assign a 1unit projector?

[Tim Ellis]

Rescue me from my ignorance. What is Real Scale option supposed to do? Assign a 1unit projector?

Real scale
Checking this box will make Studio use a 1mx1mx1m projector for this texture, regardless of what other projector is applied to the object.
This is very useful for creating reuseable materials which you can simply drag and drop on any size object.
eg.:- If you want to create a material with 25cm tiles, check the real scale box, & set the tiling for both x & y to 0.25. Now you can drop this material onto any size floor & your tiles will always be 25cm.

very wierd tim, i dont get it???

never heard a texture can have dpis? how you would measure that. texture scale is in space. i thought a texture can have meters or centimeters or feet etc...you need the info of course- with arroway p.e. you know how big the textured part is (somehting like 9x9m).

This then is my mistake, when I open a texture in Photoshop, it uses the standard 72dpi which I've interpreted as what the texture is. This is obviously not correct.
On reflection, how did Arroway come to the 9mx9m values for their textures? Using the same method as myself, but with knowing the initial dpi?

but how can i have that in maxwell. i can press the checker button real scale but it seems not to do that. i still have to manulally set 9x9 m uvw in my host app.

so i dont get the real-scale feature....

maybe someone of the programmers could explain how they meant it?
thanks & cheers
stefan

Check the quote above from the manual, your uvw mapping is ignored when the real scale box is checked.

This is how I understand it:-

I have this texture & want to use it as a real scale material.

So I open in PS & open the image size dialogue:-

This is where I get my real scale values for the texture & the dpi setting. This is where I mistook the dpi as set by the texture map.

So from this, I use 0.22 in the x tiling box & 0.24 in the y tiling box. Which when applied should give me 22x24cm tiles regardless of any uvw projector I previously applied.
(It is neccesary to round up the decimal places due to Maxwell only having 2 decimal places for the textures.)

It is very important that the mesh object is at the correct scale, otherwise the tiling will be correct for the world space, but maybe incorrect for the mesh object.

Hope this helps,

Tim.

[kraemerJK]

Well, since arroway did the intial photography for the textures, they obviously know how big the patch was that they used.

Regarding dpi : Could it be possible that there is indeed a resolution factor ? Maybe that 72 dpi is standard, and if you use a 150dpi map that the size would differ ?? I do not know, and I would not think that way.

[Tim Ellis]

Well, since arroway did the intial photography for the textures, they obviously know how big the patch was that they used.

Regarding dpi : Could it be possible that there is indeed a resolution factor ? Maybe that 72 dpi is standard, and if you use a 150dpi map that the size would differ ?? I do not know, and I would not think that way.

From what I remember the dpi increase is proportional to the resolution decrease. Or something like that.

If you used a 150dpi map, at the same resolution, then yes, but a 150 at a larger resolution might not.

Please forgive me if I'm now typing rubbish, it's the end of a long night at work.

I'll try some tests today if I have time.

Tim.

[Fernando Tella]

I don't think you should be touching dpis or size of the image but the tiling of the image.

Dpis has to do with printing size and resolution and not with what the image represents.

If you know that what your image represents is 20cmx20cm you should tile it 5 times. If it is 5x5m you should tile it .2 to make it look ok with a 1x1x1m projector.

[kraemerJK]

DPI can´t change anything because it is more of a concept than a size, maybe the pixel count would change something.

I am not going to use real scale anymore until I find some time to do some tests. The way it is working now, I can´t seem to control it. But that might just be humble me.

[Fernando Tella]

DPI (dots per inch) and the lenght in pixels (dots) gives you the printing size of the image. The thing is that this size has nothing to do with the size of the things showed in the picture.