More stupid questions....

(Rhysy 2) #1

Sorry - I hate to waste forum space but I have looked for the answer but I can’t find it. Anyway :
How do I set EXACT numerical values ? I know you can alter quantities by clicking and dragging along buttons, but this isn’t very precise. I ask because I read in a reflection tutorial that the empty object must have the same x and y but -ve z co-ordinates as the camera… do these values need to be exact ?

(theeth) #2
  • Hold Shift and left click.
  • Hold Ctrl while dragging.
  • Hold Shift-Ctrl while dragging.


(Zweistein) #3

mark your object (or the empty) and then press “n”. You can look or change the coordinates then. Sorry i am german, i hope you meant that :wink:

(Rhysy 2) #4

Thanks everybody ! Just what I needed.

(Rhysy 2) #5

Another question to which I can’t find the answer, but one I hope is just as easy :
How do I make animations smoother, i.e. stop the object (in this case a camera) from accelerating and decellearating between key frames ? I tried using the IPO thingyamejig and setting the location curves to vector handles modewhatsit, but it still seems jerky. Should I have done this BEFORE I started animating ? Ideally, I need the camera to increase its speed throughout its flight, although I could probably do this easily enough if I could stop the automatic accelaration/decelleration thing.
Any ideas ?

(Rhysy 2) #6

PLEASE help ! This is really bugging me…surely smooth camera movement is easy enough to do ?

(Schlops) #7

Well, it’s easy to do but hard to explain (at least for me). First of all: You can modify the IPO-Curve of your camera any time you want, so you don’t need to worry (too much) about your animation before you start.
Let’s explain it by example: Assume you want your camera to accelerate along the (positive) x-axis from frame 1 to frame 100 and you have already an IPO-Curve (the standard blender one) for it. Select the LocX-Curve of the camera in the IPO-Window and switch to edit mode. Change the righmost-handle to Vector (V-Key). Now select the left “leg” (rightclick on the left cv of the handle) of the rightmost-handle (frame 100) and grab it until it is parallel to the y-axis. You’re curve should now look parabolic. Check your animation, et voila.
I hope you understand what I mean. Try playing around with the IPO-Curves a lil bit (eg. increase the size of the handles), and you will see how to handle the handles (OUCH).
Further explanation for the standard blender IPO-Curve: First it accelerates, then goes on with constant speed and slows down in the end until it stands still.

(Rhysy 2) #8

Thanks, Schlops ! I think I understand what I should do… but I’m afraid I don’t know how to go about it. Everything you say makes perfect sense, but in my ignorance I do not understand the terms “vector handle” and “leg” (well I might… I’ve played around with the IPO curves, but I don’t know the definitions). One other thing - the course the camera follows must be quite precise - I am making it fly through a wormhole and so it must remain inside it at all times. Will altering the shape of the curves affect this ?

([email protected]) #9


here this tut may take care of the ride through the worm hole for you:

after you parent the path to the camera, then open an ipo
window and look at the windows bottom header and press the
button with the little wiggly arrow(display curve ipo)

here you can set your speed with the “handles”, just play around you`ll
get it:)


(Rhysy 2) #10

Thanks for the tutorial, I’ll let you know how I get on.

My friend is having a severe and irritating problem - every time he adds something to a model, Blender apparently turns it into triangles. Any idea what’s going on ?

(Rhysy 2) #11

Okay, this paths idea is working well, but… how do I change the endframe of the animation ? When I first render it, the camera automatically stops moving at the end of the animation, but altering the endframe of the animation doesn’t seem to alter the endframe of the movement. I looked on Blender Knoweldge Base which told me I could alter the IPO curves (uuurrrgghh !!! Ghastly things…) except I don’t seem to have any. I’d prefer not to use these unless I have to - what can I do ?

(theeth) #12
  • Select the curve
  • Go to the Animation Buttons window (F7)
  • Change the PathLen setting

But, this only modifies the time it takes to go from one end to the other, it doesn’t change when it starts and end moving. You’ll have to fiddle with the IPO to do that.


(Rhysy 2) #13

Thank you ! That sounds like it should work… except it doesn’t. The length of frames it takes the camera to travel from start to finish in unchanged. Also, when I go to IPO curve screen, I don’t see anything. I’ve tried selecting both the camera and the path but to no avail. I am probably doing something daft… but it’s got me mystified.

(tordat) #14

Ok, now I have a try. :wink:

If I understood so far, the problem is a path animation with number of frames to set and varying speed to set.
That’s what I would do.

-Create path (menu) or bezier curve.

  • make curve parent of the camera or whatever should move.

  • select curve

  • in anim buttons (F7) select curve path (curve follow, if needed)

-on the Path len: button adjust the desired number of frames and - that’s important - enter the same frame number in the Map new button (dont’ know why this is necessary, but it is.)

  • this should give a uniform movement of the object with the adjusted frame rate.

  • to make non uniform movements one has to work with a time IPO.

  • the time IPO is created by selecting the moving object, than leftclick Time in the IPO window (turns white), move the cursor over the grid and create the IPO by Ctrl + left mouse button.

  • shape the IPO as you want but take care not to have values below zero (that dosen’t give sense in time)

  • horizontal IPO or negativ values = no movement

  • incresing IPO = forward movement, speed depending on the gradient

  • decreasing IPO = backward movement, speed depending on the gradient

Hope this works

(haunt_house) #15

your questions are not stupid at all. The way you named the topic (more stupid questions) was less clever. Since this is a questions forum…

Try a short description.


(Rhysy 2) #16

Thanks, HH !
Maybe I should have called it “obvious questions”… the first one is probably obvious to everyone, but it seems the later ones are not. Ah well, never mind, I’d rename it if I could but I can’t.
I’ll put my future questions as seperate topics… I was hoping there would be an easier way to alter the way Blender moves objects in frames (seems to be like it would have to be a lot more complicated to do the auto accel/decell thing than just to do constant speed so I expected an option to turn this off) hence I foolishly thought the answer would be obvious.

Tordat :I’m making progress now, thank you ! I now appear to have constant speed along the path. Now fot the tricky bit… continuous acceleration. Let me see if I understand what you are saying :
The time IPO curve determines where my object is along the path at any given time, with its displacement on the vertical axis and the frame number along the horizontal axis. Hence, a steep part of the line means its moving very fast - forwards if the line is going up, backwards if it’s going down. A curve in the line determines acceleration, the rate of curvate corresponding to the exact value. So, if I want smooth, continous acceleration I need a nice parabola as Shlops says.

All well and good, I hope, but once more I encounter a problem. I made a smoothly curving upwards time curve as you described, while the camera was selected. Yet this did not alter the acceleration or the position of the object along the path at any given frame at all. Am I missing something ?

Also, what are the units along the vertical axis in the IPO screen ?

Thanks for the help, people… nearly done.

(tordat) #17

Hi Rhysy_2.

I propably mixed something up and what I wrote is wrong in parts. :frowning: (But it worked somehow).
You are right when you miss something. It is the glue between path animation, Speed IPOs, Time IPOs ,LocXYZ IPOs, and time mapping by blender.
Finally it will be quite easy, but first I have to mix up all this and give it an order again. I’m curious about it.
I’ll post may results within the next 24 h and than your problem should be solved in an acceptable way, If you didn’t it anyway, meanwhile or somebody else.

Sometimes good questions make the :-? “teacher” :-? learn something,
even if the topic is not realy good :wink: .

(haunt_house) #18

Please Do not be angry, everyone. I´ll do it all over again. Is easier to me:

Create a camera
create a nurbs curve (press F9key and click endpoint U) and shape it, then leave editmode.
Select the camera, then shift-select the path.
Hit Ctrl-Pkey to make the path parent of the camera.
If needed, select the camera and hit Alt-Okey to clear its origin.
hit F7-Key for the animation buttons.
select the curve and press curvepath (maybe curve follow).
Map new is not important to me.
If you use a speed ipo, pathlen is also irrelevant.
select the camera and adjust the trackx y -x-y a.s.o. keys, so that your camera is looking into the right direction.

(Normally I set a second curve with an empty and give the camera a trackto constraint to the empty)

select the curve and split the window. Make the second window an ipo window.
in the ipo window, press the little button resembling the animbutton.

the word speed should appear.
Make two leftclicks with ctrl on different locations into the window.
now adjust the curve as you would a normal curve with Tabkey and select or Nkey a.s.o.
put the first vertex to the desired startframe and 0.0, the second to the endframe and 1.0

Shape it as a parabolic curve by selecting the left handle of the right vertex. Press Gkey and move it down.

This should work.

If it doesn´t, I shave my head and become monk.


(tordat) #19


haunt_house’s answer is the right one for your problem.

path animation with nurbs curve as path (smoother movement) and Speed IPO (anim button in IPO window)
for tuning accerleration and deceleration. Second path animation for an empty
tracked by the camera for a better control of the view.

That’s what I figured out. Hope that’s kind of what it is all about.

I’m graetful for every correction.

Speed IPOs (for path animations)

Determines path speed.
Values for the vertical axis 0 -1.
Unit of the vertical axis is fraction of the path length.
if the Speed IPO has the value 1 for frame X your object is at the end of the path at frame X
if the Speed IPO has the value 0 for frame Y your object is at the start of the path at frame Y
if the Speed IPO has the value 0.33 for frame Z your object is at the first third of the path at frame Z

Acceleration, deceleration, and direction of movement are determined by the shape of the IPO.
Positiv slope: forward movement
Negativ slope: backward movement
increasing gradient: acceleration
decreasing gradient: deceleration

Absolute path length is determined with the PathLen Button (Anim Button menu)
The complete animation is displayed only if the animation length set in the Display buttons (F10) equals the path length or is larger.

The overall speed of the animation can be set with the MapOld and MapNew buttons in the anim buttons menu.
Important is only their proportion not the absolute values.
MapOld (100) / MapNew(100) = 1 ; default speed
MapOld (100) / MapNew(200) = 0.5; half speed; meaning a path animation with Pathlen=100 needs 200 frames to complete (one has evt. to adjust values in Display buttons)
MapOld (200) / MapNew(100) = 2 ; double speed; meaning a path animation with Pathlen=100 needs 50 frames to complete
These settings are global and effect the global time mapping and therfore all animations in the scene.

To adjust the speed for a single movement out of different animations in the scene one uses Time IPOs
Time IPOs give an object its own clock or time mapping relative to the global time mapping.
Time IPOs can affect every movement of objects including non path animation which have no Speed IPOs
(e.g. KeyFrame animations, particel systems)

Time IPOs

Determine individual time mapping relativ to global time mapping
Values for vertical axis 0 and every positiv number
Unit of the vertical axis is individual frame


individual frame = 100, global frame = 100 object is displayed in the global animation at frame 100 with its state at frame 100 (normal)
individual frame = 50, global frame = 100 object is displayed in the global animation at frame 100 with its state at frame 50

Acceleration, deceleration, speed, and direction of movement are determined by the shape of the IPO.

Speed: determined by the absulte value of the gradient (gradient = 0 = no speed; gradient = 1 = normal speed; gradient < 1 = slower, gradient > 1 = faster)
Positiv slope: forward movement
Negativ slope: backward movement
increasing gradient: acceleration
decreasing gradient: deceleration

(haunt_house) #20

I hereby declare wise and mighty


the unchallenged master of this thread!

so time ipos and speed ipos are not the same?

oops, found the time ipo. Never used it before…

Blender, deep and mysterious

good explanation

humble servant Haunt_House