rule distance 3ddistance

[albertoromano]

Greetings to all.
work with proa14 based on autocad 14, the command 3ddistance works as the zoom and does not adjust the focal distance of the virtual room that is the view; also the online autocad guide that is part of this sw describes the command as a zoom. the previous version I used instead (it was adt but I don't remember the number) allowed to vary the focal distance of the view "by widening or tightening" perspective views, for me it is very important in the drawings of furnishings. to get this result I am forced to create cameras with appfot and on these perform the adjustments. is much more slender than not act directly from the orbital command and the subcomanto regulates distance. Does anyone know if this change is regulated by a variable or autodesk decided this change and so should it remain?
good work and good study at the whole forum. a.

 

[GP.]

if you do not want to use appfot or room (they are the same thing) you can set the focal distance with the old view -> zoom

 

[albertoromano]

thanks gp for the answer, it is a regular menata the focal distance in this way, in acad 2004 adt was immediate with the active orbit command in the context menu adjusted the view while acting on the zoom and the focal distance. the command as it works now makes no sense because it is a double zoom and it is definitely a step back because it fails a useful functionality, vabbè, we will make a reason. Greetings to all. a.

 

[GP.]

...the command as it works now makes no sense because it is a double-seat zoom. . .

no, if you are in perspective mode (perspective = 1) that zoom changes the focal distance.
look that even the 3dorbita command is obsolete, shift+rotellina premutase allows you to rotate in 3d space without recalling any command.

 

[Tristus]

It's normal that a command that regulates the focal distance (in the specific case apofot) is a little bit more than a simple zoom. because of things, it is. you will have different results (visually, in the perspective) if you use a room with a small focal length (es 16mm) than a large focal length (es 80/100 mm). Moreover the room should at least simulate a camera. The zoom only serves to frame the final scene if necessary.
in the photographic field it is said that low focal lengths give to the more 'tridimensional' subject (very between quotes) than the high focal points. and in fact in photography, a high focal length tends to "flatten" the scene, so I would continue to use the appfot command, because it simulates the physics of a real room. all the controls that adjust the simple zoom is good to use them right when you need to give a final shot.
Moreover, with a wise dosing between f-stop, focal length, focal distance, number of blades of the diaphragm (but probably autocad does not have these advanced functions regarding the room), etc. you can even decide to activate the depth of the field, useful for really photorealistic rendering, especially for outdoors.
.

 

[GP.]

....all the controls that adjust the simple zoom is good to use them just when you need to give a final shot.

I repeat.

the "zoom" option of the "vistad" command does not adjust the zoom, but sets the focal distance, both dynamically that you digitandone the value

command: vistadselect objects or <utilizza vistadblocco="">: specify opposite angle: </utilizza>found(s) 18select objects or <utilizza vistadblocco="">:
type an option</utilizza>[APpfot/Mira/Distanza/PUnti/PAn/Zoom/Torsione/Ritaglio/Nascondi/OFf/ANnulla]: zspecify focal distance <50.000mm>: 28I swear

 

[Tristus]

But they called it zoom. autocad is not the best for these things. However, we do not confuse the zoom with the focal length (focus distance is another thing still, but in many confuse them).
What I want to say is this, example, I could zoom in a scene framed by a 16 mm room, and said zoom would only affect the total shot. adjustment of the frame to better focus on video.
this "zoom" of autocad (option of the command viewd) should, in theory, produce the same effect that you would have on a real room going to vary the focal length, that is going to choose, for example, a 16 mm or a 35 (depending on what I have to frame). zoom is all another thing. but I repeat, the autocad room is not the maximum.

 

[Tristus]

I repeat.

the "zoom" option of the "vistad" command does not adjust the zoom, but sets the focal distance, both dynamically that you digitandone the value
I swear

and would you also swear that by changing the focal distance that would affect the scene? It seems strange that going to "focus" one point rather than another, you would have significant changes regarding the zoom. If you have the depth of the field activated, this change of focal distance could at the limit produce blurring in case the combination between f-stop and focal length is congegnal to this purpose. In fact the focal distance is the focus distance. but re-repealed, autocad is not exactly the maximum in the management of the room.

 

[GP.]

if we talk about camera unfortunately I am not able to say something appreciable.
instead of autocad "vistad" is the only tool, even if obsolete, to adjust the angle of recovery with alternative methods to those in use in the last versions.
Moreover it was introduced almost 25 years ago (two geological ages) to regulate the v3d in maniera dInamica. adjusting the zoom as we mean it now with the distance option, while with the zoom option adjusting the focal length (length.
autodesk had decided so...

 

[Tristus]

Yes, that of autocad is a spartan management of the room. 3ds max has features that allow to simulate the real physics of the lenses. I intervened because when I read the post of Albertoromano, in which he said he had the need to frame a scene of interiors, then it is necessary to spend a little more time 'smantling' on the room, because a proper frame contributes to obtain a nice rendering.
in the interior above all there is the need to choose a goal that allows a wide view. so you need to go to the room and set an appropriate focal length, for example a 16mm.
with a 35 mm you'd be very short. for outdoors a 35mm is fine, for indoors no.

choosing a focal length rather than another, can sometimes contribute to a good rendering. Small focal lengths from 16 to 35mm are able to give more ' three-dimensionality (photographers speak of three-dimensionality of the scene') to framed objects. For example, if you frame a building with a 18mm lens, and make the same shot with a 110mm lens (clearly moving away to have the whole framed building) you will notice that the 110mm shot is flatter. It is the same effect that can be seen during long shootings, such as taking f1 cars from far away with lenses that have large focal lengths, from 600 mm and beyond.
So when you want to make an interior or exterior rendering, it's good not to rush into the room setting. It's good to have some photography. also because autocad, with mentalrays bakes bei renderings very realistic, which have nothing to envy to vray or maxwell.

 

[Tristus]

Anyway, I see that compared to so many years ago, autocad made some progress. you can also manage the depth of the field.https://www.autodesk.com/products/f...ngs-make-your-renderings-look-more-realistic/3ds max goes much further, it is possible even to establish the fstop (the width of the aperture) and the number of blades of the diaphragm itself (when the need to exalt the vents (clearly with the depth of activated field) in particular renderings.http://www.fotografiaxtutti.it/2016/07/22/sfuocato-sfocato-bokeh/

 

[albertoromano]

Good morning, everyone. I thank you for the interest in the matter, in particular tristus centered in full the core of the problem, we do not discuss objectives from 16,35 or 600 but of dynamic regulation of the opening or closing of the scene that is an internal setting. the closest thing to what I mean is the zoom subcommand in the view command, as correctly says gp. Now the question is:
"what is the macro of this subcommand?" the view command does not appear in the list of the customization window and let alone the subcommand, I would use it to create the key to insert in the toolbar so as to avoid the click turn every time. a greeting, good study and good work at the whole forum. a.

 

[Tristus]

I press that my last rendering with autocad dates back to more than 20 years ago (without mental ray, only in ray trace) so I'll have to take a look at the autocad room to help you better.
Now, in principle, I would say that the focal length is very important with regard to the frames, where the focal length is defined as the one indicated in the lens.
with a fixed 50 mm lens you will hardly be able to frame half the room (you will score much less). And there's no zoom that I'm gonna hold that will allow you to frame more than you're in 50mm.
unless you mean the focal length change that so many goals allow. but it is not a true zoom, although visually we notice an extension of the visual.
Many goals in fact, turning the wreath, can pass from one focal length to another.
for example the basic goal in the entry level of the nikon, which ranges from 18mm to 55 mm simply by turning a wreath in the target. Bringing it from 18mm to 55mm you notice an image enlargement but you will also have a reduction of the framed space, effect that in a narrow environment like a room will be even more evident than outdoors.
Unlike those fixed objectives, which do not have the "zoom" (impropriately called zoom) and have only one focal length.
the same speech applies in room management in programs that simulate cameras.

 

[Tristus]

only a small premise, even at the cost of being prolixally repetitive, because in this field it makes a lot of confusion, moreover a good rendering (and mental ray on autocad sforna bei rendering) can't ignore an appropriate choice of lenses, (expressed in focal lengths) positioning of the room, choice of lights, materials, mapping etc.
in autocad we have the "focus distance", but in my opinion it is a mistake to call it this way because that can cause confusion. In reality with that term autocad means focal length, in fact said value of "focus distance" is expressed (in autocad) in mm while in real photography the focal distances are always expressed in mt, and correspond to the focus distance, so that of autocad is not a focal distance.
It's a focal length that autocad calls improperly focal distance.
so going to adjust (by autocad) only that value to adjust our frame is as if we went to photograph a building and noting that in the frame the building is too small we went to change goal (that is, going to vary the focal length) instead of approaching the building. This could cause a loss in perspective in case we used a large focal length.

This is done, on 3ds max there is something that allows you to adjust the room a little more dynamically, but if you look at any tutorial, who makes rendering uses little and nothing these options. They establish which goal to use (focus length) and place the room with the mouse, also moving the target room if necessary. the "dynamic" option that is used most is a lower right icon that allows, once selected the room, to rotate the perspective by acting on the movements of the room. in practice rotate the perspective and the room rotates accordingly, but it is used in maximum frames, or for small adjustments. The "film gate" (on 3ds max) (personally never used) is also used for small adjustments, which zooms but without changing the focal length (as on autocad, acting on the "visual field" which also makes the focal length vary. In any case, once they have established which focal length to use, they try to leave that and act with the mouse on the position of the room.
Therefore, in my opinion, the best thing to do, even in autocad, is the same: to establish the "focus distance" in mm (16/18 mm for interior and 35/50mm for outdoors, and to move the room with the mouse or the target room. As far as I could see, there are no commands that allow dynamic adjustments comparable to those of 3ds max, in any case they are not fundamental.

 

[albertoromano]

thanks tristus for the exhaustive explanation, I will definitely try to follow your suggestions. Greetings to all. a.

 

[Tristus]

However, the fact that autocad has that appfot preview suggests that it does not have any dynamic regulation of the room, where the dynamicity of the regulation is meant that moving the room, this will return the real-time vision of what it is setting. to have this vision in real time it is necessary to keep the preview active. and this is very uncomfortable, unless you set the preview window in a way that covers a separate pane entirely. But the trouble is that if you go then click on another window, that of the preview disappears and it is necessary to reclick it. All this is very uncomfortable.

 

[Tristus]

However, the fact that autocad has that appfot preview suggests that it does not have any dynamic regulation of the room, where the dynamicity of the regulation is meant that moving the room, this will return the real-time vision of what it is setting. to have this vision in real time it is necessary to keep the preview active. and this is very uncomfortable, unless you set the preview window in a way that covers a separate pane entirely. But the trouble is that if you go then click on another window (such as the view from above) that of the preview disappears and it is necessary to reclick it. All this is very uncomfortable.

 

[Cristallo]

tristus allow me dissertation, even if we talk about sophisms.

focal distance (or focal length) are two terms that are equivalent to the fact that the first is often elusive and remains only the term "focal", and represents the distance between the center of the lens and the plane (representing the lens) on which the image of an infinite point is on fire. the focus of a subject that is not infinite is obtained by approaching or removing the lens from the plane (film or sensor)

the focal distance is not the focus distance, which in reality in an optical system does not have a real sense, since depending on the opening you have a different "field depth", an area where the subject is on fire even if the focus is not exactly on the focus distance.

in autocad (as in other software) the concept of fire is not applicable (but seen a render with the blurred background or with the first blurred plane - something absolutely indispensable in a photograph), but the concept of focal is used to represent (more or less) the perspective deformations due to the use of a given objective.
It should be said that the focal values used by the programs refer to the (old) photographic format 24x36, today called in digital as "full frame".

According to this reference, a 50mm focal lens returned an image with distortions and amplitude (field angle) very similar to normal human vision.
therefore all the values below 50mm went towards the wide angle, all the above went towards the telephoto lens.
the field angle (size of the framed portion) directly determines the geometric distortions necessary to re-enter this portion in the size (fixes) of the sensor/film.
The less focal point has the objective, the more distortions are accentuated, so much so that below certain focal points (16mm for 24x36) the distortions are so extreme to assume a special name (fish eye - fish eye).
less focal has the objective, the more lines that are not parallel to the recovery plan converge towards one point.

with the adoption of sensors of different sizes, the "focal" assumes different values, in modern cameras with aps-c sensor the "normal" objective (50mm) instead becomes 35mm.

said this, in autocad as in other program, if you want to represent an object with a point of view close to normal human vision, you stick to a focal point of 50mm.
If you go 15-18mm indoors, show you more space, but you will also give to those who look at the image the impression that the interior is much bigger than what is actually not.

 

[Tristus]

I respond with great delay to the post due to some inconvenience to the computer.

in autocad (as in other software) the concept of fire is not applicable (but seen a render with the blurred background or with the first blurred plane - something absolutely indispensable in a photograph), but the concept of focal is used to represent (more or less) the perspective deformations due to the use of a given objective.

in fact to call "camera" that of autocad is a little exaggerated. with autocad you can still get those perspective distortions you talk about, however, that you do not vary the focal length to adjust the frame, because the risk that you run is to lose those distortions (which give the scene more 'rotondity) risking you have a flat frame. I am not talking about the exaggerated prospective distortions of so-called fisheyes (those from 10mm down), but those inevitable prospective distortions typical of the most 'used focal points in photography, when you want to represent buildings both inside and outside the vision of a building resumed from 50mm to 50 meters away will not be the same as the same building taken from 200mm to 150mt.
the frame should always be adjusted by moving the chamber physically once the focal range is established within which to keep. if you have a software that allows you to make it dynamically so much earned, especially in time. in any case it is almost always the camera that moves. You can also adjust the frame by changing the focal length, but it is important to know how much you go to disconnect from the focal value that we imposed ourselves, just to avoid losing those perspective distortions thus avoiding an image too flat.

speech aside should be done for blurring. It is not necessary, but in my opinion, if you want to make a nice rendering of a building with, for example, trees in the background, give a hint of depth of field to make sure that the trees at a certain distance from the building are slightly blurred, helps in understanding the scene.

If you go 15-18mm indoors, show you more space, but you will also give to those who look at the image the impression that the interior is much bigger than what is actually not.

We must not overdo it. for interiors, a 18/24mm go well. an interior of a 4x4mt room is good to approach it with a 24mm lens up to 18mm if you want the room to frame more than one wall. the speech changes if you are making a representation of a 10mt x 9mt salon, you can use a focal length up to 35mm. depends on cases.
in any case, any real photo (i.e. taken with a real camera) responds to lens physics, so in any case (rendering or real photo) you will never have the exact representation of the real size. for this reason, in order not to have unpleasant surprises in the picture, when you prepare the room for a rendering, it is good to do it as a photographer would, knowing big way what focal to use.

 

[Tristus]

(never seen a render with the blurred bottom or with the blurred first floor - absolutely essential in a photograph)

Yet the vast majority of photos are hardly set on fire properly.
today, with the use of the compacts, or even with the use of our smarphone to take our photos, we still have sharp photos. or better, they're sharp, but if you go zoom in on the photo you notice all the compromises that make these machines to give you a "nitida" photo.
for how they are conceived (focal and fstop) have a high field depth and therefore you see almost everything sharp even if you did not look at where to focus. Moreover they are made to take pictures quickly, rightly without thinking about it.
the speech gets complicated if you have a reflex, with various goals, and you do not know the hyperfocal and its rules.

said this, all the photos never give objects focused, apart from the object on which we really focus (that's why the importance of focal distance). Everything in front or behind that object will be in a field of sharpness. field of sharpness whose dimensions (usually expressed in mt) are determined by the focal length of the used objective and the f-stop used when shooting.
this in real photography
with software what happens?? if you do not activate the depth of field, everything will be perfectly on fire. perfectly sharp and perfectly on fire, even if behind the construction we whip a very high distant road km. the difference is that in the photo taken with the machine you have the exact perception of what you are looking at. Hardly the software will give you that same perception, because that traliccio will seem to you a few meters from the building.
benign, the depth of field is not indispensable, and it also increases rendering times, but in certain cases it can help in understanding the scene