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CAD

Posted: Tue Dec 09, 2003 12:26 am
by dEs_iGn_eR
In addition to features already mentioned, I would like to see better co-ordinate manipulation features. Perhaps integrating the current rotate and pan with a numeric fine tune would be a nice touch, click to define origin, a more visual approach to Autocad's ucs wcs. Solidworks fails in the co-ordinate manipulation area, especially for large projects.

Also, a scalable tablet overlay printout, once you setup your preferences, hit overlay print? or something... just an idea.

Re: CAD

Posted: Tue Dec 09, 2003 11:12 am
by thorwil
dEs_iGn_eR,

could you please explain in as much detail as possible what you're talking about? I guess most Blender users and developers know nearly nothing about CAD. And others like me know only 1 or 2 apps and their terminology.
Personaly, I know Solidworks but not Autocad.

With all the stuff mentioned here, we should collect it and work it out to one consistent proposal. It must be clear how everything is supposed to work, what it's good for, how it fits into Blender and what it shoud look like.

I might put up a page for this later on, but right now I have other priorities. But if somebody else is willing to organize this, I will surely contribute.

Re: CAD

Posted: Tue Dec 09, 2003 2:51 pm
by matt_e
dEs_iGn_eR wrote:In addition to features already mentioned, I would like to see better co-ordinate manipulation features. Perhaps integrating the current rotate and pan with a numeric fine tune would be a nice touch
Theeth added numerical input for transformations in 2.3. Enter your mode (grab, rotate, scale, whatever) and just start typing. You can switch between the X/Y/Z by pressing Tab. There is also the N key Object-> transform properties panel. is this what you were after?
click to define origin
You can make transformations use the 3D cursor as an origin by changing the pivot point to '3D cursor' in the 3D view header, or by pressing the . key (period). if you want to be precise, you can snap the 3D cursor to various locations, using Shift S (Object -> Snap).

Posted: Wed Dec 10, 2003 12:28 am
by steve_t
I agree with 'Knoxer' that we need real units. It would be really nice to be able to model using inches and cenitmeters instead of generic units. Being able to measure the distance between two points and being able to constrain the distance between two points to a specific value would be useful not only for more accuracy in modeling but for a modeling tool in general as well.


- Steve

Posted: Wed Dec 10, 2003 4:37 pm
by xand
i'm solidworks and autocad user beside blender.
to explain some terminology point : the ucs and wcs are user/world coordinate system are local and world axis.
i've already a script to 'emulate' this. take a look at realign_axis in the script list on elysiun
http://www.zoo-logique.org/3D.Blender/b ... axis.blend

the cad functionnality which are really need are :
-snapping
-dimensioning
-relative positioning : placing an object at a distance/angle from another object (exist directly in autocad, through the definition panel in solidworks)

+++

Posted: Wed Dec 10, 2003 5:21 pm
by thorwil
xand wrote:... the ucs and wcs are user/world coordinate system are local and world axis.
i've already a script to 'emulate' this. take a look at realign_axis in the script list on elysiun
http://www.zoo-logique.org/3D.Blender/b ... axis.blend
From the script list:
Script to align axis of a mesh to the axis of another objects without rotating mesh.

Could you please explain what's the point in doing that? I'm sure it's useful, but I can't think of a scenario. Better make sure it's clear for what a feature is useful when requesting it.
the cad functionnality which are really need are :
-snapping
-dimensioning
-relative positioning : placing an object at a distance/angle from another object (exist directly in autocad, through the definition panel in solidworks
I guess with snapping you mean alignment help like lineends snapping to a position vertical to another point. We need graphics to explain stuff like that. (I might take care of this, but not this year, I think. But anybody should feel free to come up with something here.)

About dimensioning and relative positioning: It would be nice to have an unified system. Using the same tools in sketches and assembly. Does anybody know an application that does that? (Solidworks is fractured in this regard.)

Re: CAD

Posted: Wed Dec 10, 2003 5:30 pm
by koxinga
broken wrote: Theeth added numerical input for transformations in 2.3. Enter your mode (grab, rotate, scale, whatever) and just start typing. You can switch between the X/Y/Z by pressing Tab. There is also the N key Object-> transform properties panel. is this what you were after?
It's not possible to enter decimel point ? I would be better with it

Posted: Wed Dec 10, 2003 6:22 pm
by bleber
koxinga

for enther a decimel point you can press the point key (.) in the normal keyboar, no in the numerical zone. 8)

Posted: Wed Dec 10, 2003 8:16 pm
by xand
thorwil
in my script, there are objects in ready to try.
how it works : you select a first object (mesh or empty) and a second (mesh), you issue alt+p; the axis of the mesh selected in second turn to be align with the axis of the first one but the vertices don't move.
if you use r, axis and vertices rotate;
with ctrl+alt+a, the vertices stay in place and the axis come back to initial.

the initial size and location of the mesh are not affected against ctrl+alt+a.

+++

Posted: Wed Dec 10, 2003 8:23 pm
by thorwil
xand,
I know how it works, but I don't know why one would want to align the axis of one object with that of another.

Posted: Thu Dec 11, 2003 12:49 am
by xand
so you can use all the power of local axis constraint for grab, rotate and size.
imagine you want to move your mesh 2 units at 35° from horizontal.
you create an empty rotated at 35°, turn the axis of your mesh, grab in local axis. and if you've first create an empty to store you initial orientation of axis, restore it.

another case is when you've made multiple extrusion or pet, the axis could not be align exactly as you need (for example for armature), use the script to correct this.

it will better if it was hardcode as ucs in autocad.

+++

Posted: Thu Dec 11, 2003 1:58 am
by theeth
You mean something like Ctrl-C -> Rot which copies the rotation from the active object to the selected object?

Martin

Posted: Thu Dec 11, 2003 10:18 am
by xand
exactly, you add an option 'axis only' in ctrl+C->Rot and that's what the script does.

+++

Posted: Thu Dec 11, 2003 3:11 pm
by theeth
Axis only is fun until a gimbal lock occur and you're fed phoney values.

Martin

Posted: Sun Dec 14, 2003 11:15 pm
by knoxer
NOOOOOOOOOO!!!!!! Please don't implement those stupid UCS/WCS concepts in "BlenderCAD tm" :shock:

Has anyone else here used Autodesk Inventor? I hear it's a lot like SolidWorks, but I've barely used SW. I've used both AutoCAD and Inventor for thousands of hours each, and I really like how Inventor works. I like it because you NEVER have to worry about where your axis are (I've even turned off the little 3-arrow indicator because I don't need it)

This is going to be a little hard to explain without being able to show you, so bear with me... I'll see if I can work up a little web page to try to make this concept clearer later....

For part creation:

Basically you start a new "part" (new document) looking at a blank sketch on the x-y plane (by default - you can change this). You can start sketching there, or choose a different plane to sketch on.

When you're done with the 2-D geometry and you've created a 3-D solid from it (using extrude, revolve, loft, sweep, etc) you can make another sketch on any existing plane (including any planar surface on the existing solid) simply by clicking that plane and hitting "new sketch". Or you can create a new plane by revolving or offsetting from one of the existing planes or surfaces... I told you it would be confusing...


For putting together parts (making assemblies):

I didn't mention anything about needed assembly features in my previous post... so here's how it should work.

You insert 2 or more parts into a new document, and then simply start putting them together like you would in the real world. If "Peg-A" goes in "Slot-B", you just click the mate command, click on a feature on "Peg-A", click the corresponding feature on "Slot-B" and boom, they move together. You can assign several different 'constraints' like this, including mating surfaces, planes, or axes; offsetting surfaces or planes a certain distance; and setting an angle between surfaces or planes.

Then, anything that isn't constrained can still move... EXAMPLE: You have two parts, one is a cylindrical peg, one is a block with a hole in it.

You 'mate' the axis of the peg to the axis of the hole, then you 'mate' one end of the peg to the bottom of the hole. The peg is now 'stuck' in the hole, if you try to move the peg it won't come out of the hole, but it can still rotate in the hole....

ANYWAY... Now that I've babbled for so long, I'll leave you with an example of what proper 3-D constraints can do:

Image