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Posts Tagged ‘Movies’

Hi everyone! I hope you all had a good weekend and avoided making wacky searches you may soon regret. I spent some time of my own weekend toying around with PhotoWorks and the Motion Manager, trying to create some cool animations using lights.

I learned from the book Creating Animations with SolidWorks that using lights in animations is not really hard to do. Basically, you have your lights set up in SolidWorks, then you create a new motion study and the lights show up in the Motion Manager tree. Then, you can move them around, change their properties or even turn them on and off throughout the animation, creating all kinds of different effects.  Like with many other elements in the animation, every time you change something about a light, a key point will be created and you can drag the key point to a different location in the timeline, copy it, or even change its interpolation mode (the way it changes from key point to keypoint), just like you would do for a motor or a change in color or appearance.

So I started with this model of a flash light that I found at the 3DContent Central. The model was made by someone named Matthew Nestor and the moment I saw it I knew it was just perfect for my purposes. My idea was to add a spot light and locate it in such a way that the light seemed to be coming from inside the flashlight, like the light bulb was really on.  Notice the light in the image below.  I made it visible in SolidWorks so you can appreciate what I’m talking about.

 

While you don’t need PhotoWorks to add a spot light to the animation, you do need to have PhotoWorks for what I did with this particular light in this animation, so I’m going to assume you understand that none of this is useful to you if you don’t have PhotoWorks as an add-in and activated.

To create the effect I wanted with this particular light, I made it a fog light. What this does is create an effect similar to what it would be having some fog, mist, or light rain, allowing the beam of light to become visible. I won’t go into much detail on this, but you can learn more about how to use fog lights in the book PhotoWorks, a step-by-step self study guide, also available from the SolidWorks online shop.

 

If you notice, there are other lights, as well: there’s the ambient light, and a couple of directional lights that came with the choice of scene. I turned Directional 1 off and diminished the brightness of both ambient and Directional 2, so they wouldn’t overpower the spot light.  At zero seconds in the animation, ambient, spot1 and Directional 2 are on and Directional 1 is off.  At 1.5 seconds into the animation, however, Spot1 is now turned off, as you can see in the image.  As soon as you turn the light off  in the animation( by dragging the time bar to 1.5 seconds, selecting the light, right clicking on it and selecting Off), a key point will be created at 1.5 seconds. If you hover your mouse over this key point, you will see all the light’s properties at a glance.  The empty light bulb icon indicates the light has been turned off; if the light was on, the light bulb would be colored yellow.

 

Something else to keep in mind is that, unless you specify otherwise, the interpolation mode is always linear, which means that the light will go from on to off in a linear fashion, little by little, instead of turning off all of a sudden at 1.5 seconds. This will become an important factor for this animation. You’ll see that in a bit.

Due to the amount of time invested in rendering every frame for the animation in PhotoWorks and the fact that there’s 7.5 frames being generated for every second of animation, I meant for it to be very short. This particular one lasts less than two seconds, but it took close to 40 minutes to render and complete. I added an extra key point at 1.8 seconds, that was basically a copy of the one at 1.5 seconds. I just wanted to have at least a fraction of a second to appreciate that the light had, indeed, turned off.

One thing to keep in mind is that you will not be able to see the effect of the fog light on your screen when you calculate and run the animation in SolidWorks. You will only see it when you either render the image at a particular time in the animation or produce the animation as an AVI file using the  PhotoWorks buffer.  Taking this information into account, I set up all my options in PhotoWorks and test rendered the image at zero seconds and again at 1.8 seconds. I liked the way the renderings looked, so I decided to save the animation as an AVI file and this is what I got.

If you notice, right at the end of the video, after the flash light has turned off, it almost looks like it’s turned on again.  I tried a few things, tweaking the other lights in the animation and such, but it didn’t help, so I decided to change the interpolation mode for the Spot1 light, instead, from linear to snap. This new interpolation mode makes the Spot1 light turn off instantly, instead of linearly.

 

I rendered and produced the AVI file one more time.

Unlike before, now the flash light turns off instantly and it doesn’t look like it’s turned on again. I don’t know about you, but I think this animation looks a lot better than the previous one.

I know, I know… This is getting long for a blog post, but just before I go, let me show you just one more of my whimsical experiments with lights in animations. Some of you may remember this model. Some time ago I made a cute rendering of some holiday lights using PhotoWorks.  Now I’m going to use the same model to animate those holiday lights. As you can see in the image below, there are four point lights of different colors, strategically located to make it look like the light is actually coming from the light bulbs. I’ve made them visible for you to appreciate them; they appear in the graphics area as dots of color over the light bulbs. The black dots are lights that are turned off at that moment.  I’ve altered the color of each of them to make them look like holiday lights. 

As you can see, these are also fog lights, just like the previous one.

 

For my animation, I alternated turning a couple of them off and leaving a couple on every 0.5 seconds. First, the green one and the orange were on.

 

Then the red and the blue were on, while the other two were turned off. I used Snap as the interpolation method for all the lights.

 

I copied and pasted some of the key points to turn the lights on and of again and make the animation last for 2 seconds, then checked my PhotoWorks options, did sample renderings at zero and 0.5 seconds,  and produced the AVI file. This is what I got.

Not bad for an experiment, huh? There’s tons more to learn about lights and animations in SolidWorks. If you’re curious, check out the books offered by your local VAR or go to the SolidWorks online store and start experimenting today.

This is a very short post with the only intention of showing you a little video where I’m driving movement in an animation using only an angle mate. The video was also made made using SolidWorks 2010 Motion Manager and it’s the same model of the scissors that  I used before, but  it kind of didn’t fit well with the other two examples, so I decided to make a separate video about it. There’s also a little something on changing views during the animation. Hope you find it useful!

 

Hey everyone!  I know it’s been almost a month since the last time I blogged.  I also know quite a few of you still visit. Thank you!  Contrary to what the rumors may say, I’m still alive and this blog is still active, just not as active as before.  I’m sorry! Truth is this summer – this whole year – hasn’t been exactly one of the best ones for me and I’ve been seriously tied up with family responsibilities and other mundane activities. Bo-ring… I know.  Precisely for that reason I considered having a friend of mine as a guest blogger every now and then, just to keep the ball rolling during those times when I can’t come up with something to write about or when I just can’t find the time to do it, but he’s not convinced this is something he may want to do.  I guess I haven’t nagged enough.

As I mentioned a couple of posts ago, I’ve been reading the new book Creating Animations with SolidWorks and I’m already halfway through it.  At the risk of sounding like a bad commercial, I must say that this book is really worth the time and effort.  It is very easy to read, straight forward, and will quickly provide you with the tools you need to create really cool animations without complicating your life.  

I think one of the most important things I’ve gotten from this book so far is the understanding of what making an animation in SolidWorks is really about. You see, I started the process backwards, attempting to understand SolidWorks Motion first, before learning about animation, and I was confused because all three kinds of motion studies use the same interface: the Motion Manager, although they are definitely not the same thing . This book has helped me finally understand why many of my previous attempts failed, and find different ways to get the movement right.

I’ve learned that sometimes you may get the results you need by dragging parts, sometimes you may drive the movement using distance or angle mates and yet some other times you may use one or several motors to accomplish the same.  And you can combine these elements too! Reading chapter seven I learned how to apply motors, how to turn them on and off throughout the timeline, reverse their direction, change their speed,  and change the interpolation mode to affect the way they operate, thus ultimately changing the way the whole animation looks like. I also tried one kind of motor I hadn’t tried before in an animation: an interpolated motor, driven by a tabulated set of values. This sort of motor is pretty cool, because it’s easier than trying to keep track of several key points throughout the animation, especially if you have other motors that you are trying to synchronize.

Anyway,  I put something together really quickly, trying to answer the second question from the same reader of the chain. He wanted to know how to animate screws so it looks like they are actually being screwed or unscrewed during the animation of an assembly exploding or collapsing. I tried two different things, based on examples I found in the book.  If you want to know more, I recommend you get a copy of the book Creating Animations with SolidWorks from your local VAR or the SolidWorks online store.

For the first method, I created a manual animation of the explosion of a pair of scissors. By manual I mean that I didn’t use the Animation Wizard, but dragged and positioned the components myself, instead.  Notice that, in order to do this I had to suppress a few of the mates in the assembly or else the components wouldn’t budge at all.  For the second method, I used the Animation Wizard to create an animation of the assembly explosion first and then tweaked the animation a bit.  In both cases, the rotation of the screw was achieved by using a screw mate. Please, forgive me because these two animations are extremely rough. I didn’t pay too much attention to details and views, etc., so they may not look as nice as they could had I spent a little more time working on them. Anyway, to watch the video simply click on the image below.

I had mentioned in a previous post that I was working on a motion study using a model of a pair of friction grabs. Here I have a short video of that motion study, demonstrating the use of friction when defining 3D contacts for motion analysis.  

When defining 3D contacts for motion analysis in SolidWorks Motion, we have the option of acknowledging there’s friction between the components or not. Sometimes, no friction works fine for the kind of model we are working with, but there are other times when our simulation won’t work at all unless we add friction to the 3D contacts between the components.  My friction grabs, as you will see in the video, are one of those models that need the friction in order to work.

Dry friction, also known as Coulomb friction force is calculated based on a couple of coefficients:  the static coefficient and the kinematic coefficient.

The static coefficient is a constant related to the force necessary to overcome friction when the body is at rest, as expressed in this formula.

Fm = µs N

Where Fm is the maximum value of the static friction force, µs is the static coefficient and N is the normal component of the reaction force acting on the body.

The kinematic coefficient is a constant related to the kinetic friction force, which is the one acting on the body once it’s already in movement and its magnitude is usually much smaller than that of the static friction force. The magnitude of this force remains pretty much constant as the body’s velocity increases.

Fk = µk N

Where Fk is the kinematic friction force and µk is the kinematic coefficient.

Both coefficients usually depend on the nature of the surfaces that are in contact, but not really on their shape or size. Some values have been obtained experimentally and organized in tables. To use these coefficients all we’d need to do would be to determine what kind of materials would be in contact and find the coefficients for that particular combination from the tables. SolidWorks simulation has a small collection of materials for contacts available. When we choose materials from this list for our 3D contacts and mark the option to use friction in the 3D contact property manager, the coefficients for that particular combination are already determined for us. However, we can always clear out the option of using materials from the list and enter our own values for the coefficients, if we know them from some table or from experimentation.

In this little video of the simulation that I put together, I run a simulation first without friction and then with friction added to the 3D contacts between the grabs and the block.  Notice that, in my model, the tongs and block are made out of steel; however, since I choose rubber (dry) for the material in my contacts, it is the coefficients for this kind of material that will be used in calculating friction forces and not the coefficients that would apply for a combination of steel on steel.

Enjoy the video! And in case you have trouble seeing it, it will also be availabe at Viddler.com, just follow the link: http://www.viddler.com/explore/lainge96/videos/20/

I stayed up late last night watching a long collection of sheet metal related videos. Some were tutorials on how to bend metal by hand or with simple tools, with a hammer, a leaf brake or a box and pan brake; some others dealt with the design of tools and dies. I know this doesn’t replace visiting a real shop and (hopefully) getting a try at bending a piece of metal myself, but the videos were extremely detailed, with lots of close up views, and at least I got to see different kinds of presses in action. This one is one of my favorite ones. Just wanted to share with you here, for those that, like me, had never seen one this before.

Maxform Press Brake on MachineTools.com