Hi

I would like to suggest the following as a request (thats assuming i haven't overlooked and its already in there!).
When i work from background images i usually start off with the top, side and front views in a pshop file. I then cut up into separate images; top, side front etc.
I then import the front image into the front window and so on. My request is that when you hit the image tab you are able to set the size of the image(s) by a percentage. This way i could make all images the same size percentage i.e. 134% and know they were all the correct size in each view.

Matt

Hi Matt, I'm not sure if I really understand the request.... Images are made up of a bunch of little pixel dots and so their natural size is "number of dots across" which does not really have any direct correlation to a specific width and height in a 3D environment.

So I'm not sure how putting in 134% could work - there has to be a well defined base size first before you can have 134% of that size...

Currently you may want to initially draw in a rectangle and then make copies of that aligned to the different views and then use that to snap on to.

- Michael

Yeap, that's what I do Michael, and it works every time for me. Effectively my unit size becomes pixel size. However I can appreciate the original request, but again it should be easily remedied by using original pixel size of image and then doing something like size+size*perecentage/100 should give the perecentage increase required to the box created to anchor the image to, something like that anyway.

Martin Spencer-Ford

Hi Martin, I'm not very sure about using the pixel size as if it were a unit size, those are pretty different things and would result in things like a picture from a high density image coming in at 3000 units across or something like that as being its preferred unit size, it just seems like that would be pretty weird.

- Michael

Hi Michael - I guess I am not coming across very clear again.

I always start my projects as "No Unit System", so if I do need to be using a background image as a tracing template I then draw a box to the same dimensions as the image, so if the images is 800 x 600 the box is drawn to the same scale as the image. The box is then positioned as mid point or centre point to origin and the image is then loaded and placed using the snaps provided by the box geometry. Once placed the box becomes locked or hidden or just plane old deleted, but once drawing/tracing commences I am still using no units system and effectively speaking the scale becomes 1 pixel of the image = 1 no scale unit of MoI, hence me saying that I am using the pixel size as a unit size. Once all the drawing is done, you can scale to what unit of measurement you need or just plane change the unit of measurement to whatever you need, feet, inches, mm etc.

All of this works fine for me right up to the point of export when the OBJ files, no matter what the unit size is, are exported as huge mesh objects. Once the object gets imported into other rendering packages they come in as massive objects, but again this can be fixed in the export mesh options by using the scaling tool provided in the OBJ exporter. If on the other hand you are using rendering engine such as KeyShot that does not seem to have a world limit until any objects are imported in then you don't even need to worry about the scaling of the exported object

I hope I have made a little more sense this time with my rambling - All the best

Martin Spencer-Ford

Hi Martin,

> <...> hence me saying that I am using the pixel size as a unit size.

Ok, but I'm not really aware of this being a common practice to base your entire model size upon the pixel size of the background images... And doing this is what is giving you the side effect of using a fairly large numbers for your objects causing the "huge objects" problem that you mention.

Instead of setting up your entire model as if it was all made of pixels, it tends to be better to instead assign some distance inside the bitmap like along one line in it to be a particular unit size, then you can use the Image align tool to pick the reference points on that bitmap line and then set that to a matching line in the model, there's a demo of that here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1982.9

- Michael

Nifty little trick that Mr. Gibson .... This will help a lot when it comes to vehicle modelling and creating 1:1 scale model. Thanks ;) appreciated!

Martin Spencer-Ford

hi probably didn't explain myself too well.
I wanted the BG image to work as Modo. When i add an image it comes in at 100%. I would then draw a circle say 100mm dia. to match the 100 mm dia. flange on the image. At this point i would scale the image of the flange to match the circle i just drew. Now i am drawing at the correct unit size.

At this point i would need to add the other images in the other views, but instead of going thru the process again it would be good to know at what percentage i scaled the first image so i can simply set the remaining images to exactly the same scale. Then would just have to worry about getting the image into the correct location.

Hope this clearer . . .

matt

Hi Mattj - Wonderful idea but I am not sure because i have not tried it yet, but by using the scaling trick showed by Michael, once you have that first image in place, as long as all the other images are the same scale, then you should be able to select the show in all views option in the image menu, then once you place and scale that first image in place, there will be visible lines in the other views that you can use as snap and reference points.

Does that help ?

Martin Spencer-Ford

thanks martin s

i will try that.
matt j

Hi matt,

> I wanted the BG image to work as Modo. When i add an image it comes in at 100%

So you mean you don't get to place it by "drawing" a rectangle for like you do in MoI? It just comes in at some fixed predefined 3D size?

MoI's background images do not work like that - instead of an image coming in at some fixed size, you tell MoI the size by drawing a rectangle. Since there is not some automatic predefined size used, there isn't anything in MoI for a percentage value to be based off of.

Just in general the "generate new object" philosophy in MoI is to allow you to draw the object directly where you want it when it is first created, so for example in MoI's sphere command it does not stick in a "default sphere" and then make you move and resize it in order to get the actual sphere you want, instead you get to draw the sphere where you want when it is first created, and so the background image mechanism is set up in that same way.


But check out these examples for how to snap images together in various ways, that may be useful for what you are asking about:

http://moi3d.com/forum/index.php?webtag=MOI&msg=2501.14
http://moi3d.com/forum/index.php?webtag=MOI&msg=2501.15
http://moi3d.com/forum/index.php?webtag=MOI&msg=1982.6

- Michael

Ok I will try your method. Thanks for all the contributions, much appreciated as ever!

Matt