archive-edu.com » EDU » H » HWS.EDU

Total: 727

Choose link from "Titles, links and description words view":

Or switch to "Titles and links view".
  • CPSC 324, Fall 2002, Lab 4
    the Invert command turns a selection into its exact opposite What was outside is now inside and what was inside is now outside This is useful if it s easy to select the part of the image that you don t want in a selection Just select the part you don t want then invert There are commands for shrinking and growing a selection by a specified number of pixels The Feather command has an especially interesting effect It makes a border around the selection in which the amount of transparency increases gradually You don t actually see the effect until you cut out the image or copy and paste it somewhere else For the flower image I scaled flowers jpg to about 0 6 of its original size made an elliptical selection feathered the selection by 25 pixels did a copy and then a paste onto a white background Once a selection has been made you might decide that you want to reposition it To do this position the cursor inside the selection then ALT click and drag In KDE this will only work if you have configured KDE to ignore ALT click as described at the top of this page If you simply click and drag inside the selection without using the ALT key you will actually move the pixels contained inside the selection The selected region becomes what is called a floating layer If you have the Layers dialog box open you will see that a new layer has been created Floating layers are also used with cut and paste so its important to understand how they work In Gimp when you paste something the pasted image is placed into a new floating layer so that the original image is still there below the pasted image This allows you to drag the pasted image into position without messing up the original image in the underlying layer Before you can proceed with any other editing of your image you must o decide what to do with the floating layer You can either anchor it which will merge it into an existing layer or can make it into a new separate normal layer Normally you will want to do the latter so that you can come back and move or otherwise edit the layer later All you need to do is select New Layer or Anchor Layer from the Layer menu at the top of the image window Note When you drag a selection with the grab tool without holding down the ALT key it is exactly the same as Cutting it and Pasting it into a new floating layer in the same image Exercise 2 Use a feathered selection and cut and paste to make an image similar to the flower image shown above Use a different image as a starting point If you want you can make your image from pieces of several different images Post the image on your Web site with an explanation of how you made it Working with Selected Regions When working with Gimp remember that when there is a selection any operation that you apply to an image painting erasing filtering color adjustments etc will apply only within the selected region Also it will only apply to the currently selected layer This can actually be very useful Here for example is a picture taken at a talk given by Leya Tesmenistky in Lansing 300 The picture is dark and indistinct except for the projection screen I would like to brighten the background colors without changing the colors of the screen To do this I need to select everything except the screen The easiest way to do this is to select the screen and then invert the image using the Invert command in the Select menu There are several ways to select the screen For example you could use a combination of the magic wand plus the lasso tool to capture regions missed by the magic wand Remember to use control click with a selection tool to add to an existing selection But the easiest tool in this case is the magic scissors tool To use this tool you are supposed to click on points around the boundary of a region the tool is supposed to figure out the exact path of the boundary between points As I said it doesn t work all that well in most cases However here it does work well To use the scissors tool just click on the four corners of the projection screen in the image then click again on the point where you started This makes a path around the screen click inside this path to change the path into a selection You should find that the screen has been neatly selected Now invert the selection to select the background Once the background is selected you can use the Levels tool to brighten the colors The Levels tool was covered in last week s lab Look for it under Tools Color Tools After adjusting the levels of the background I decided to sharpen up the image a bit by applying the Unsharp Mask filter to the entire image Look for it under Filters Enhance and maybe decrease the Amount in the dialog box for this filter Finally I cropped away part of the image using the Crop tool Exercise 3 Enhance the picture of Leya s talk leya orig jpg as described here and put the enhanced image on your Web page Include the original image if you like You can take a look at my sample solution to this exercise leya modified jpg More Advanced Selections Getting a selection just right can be difficult you should understand that an artist might spend hours just making a selection One way of increasing the quality of a selection is to work on a magnified view of an image The and keys can be used to quickly zoom in or out on an image The 1 key

    Original URL path: http://math.hws.edu/eck/cs324/s04/lab4/ (2016-02-07)
    Open archived version from archive


  • CPSC 324, Spring 2004, Lab 5
    the grid For rotation you can drag the center point of the grid to change the center of rotation Then to apply the same transformation to the image that you have applied to the grid click a button in the extra window The name of the button such as Scale depends on which transformation you are applying It would be nice to see the image transformed as you drag the handles but transformation is presumably too slow an operation to allow that The perspective tool allows you to drag each corner of the grid independently In the picture at right the upper right and lower right corners have been positioned to transform the rectangular image into a trapezoid This transformation simulates a change of perspective it will look as though the right side of the image is farther away than the left side Sort of this is not true perspective just an imitation that often works OK The tool options for the Rotate Scale Shear and Perspective tools contain an Interpolation option I suggest changing this from Linear to Cubic to get the highest quality image after transformation Note that transforming an image distorts the image and loses information because transformed pixels do not match up one to one to the original pixels If you want to experiment to find the correct transformation it s not a good idea to apply a series of many transformations to the image Undo each transformation before trying another one or your image will gradually turn into mush The Measure Tool The measure tool which can also be found in the Gimp toolbox window can be used to measure distances and angles on an image It s very easy to use just click on one point drag to another and release A line appears on the image The length of the line in pixels and the angle that the line makes with the horizontal are shown at the bottom of the image window The measure tool can be helpful when you need to scale one image to make it fit into a region in another image Use the measure tool to measure the height of the image and of the region where you want to put it Use a calculator to divide the region height by the image height This gives a scaling ratio that you can use in the Scale Image dialog box Similarly measuring angles might help you to figure out how much rotation to apply to an image Layers and Layer Masks Layers are one of the most important features of the the Gimp Almost any image composition task will involve creating and manipulation layers Whenever you are using layers it s a good idea to keep the Layers dialog open on the screen This dialog has many features for working on layers Clicking on a layer name will make that layer active All paint operations will apply to the active layer Double click on a layer name if you want to type a new name for the layer Right click to get a menu containing many layer operations Some of these operations are also available as buttons at the bottom of the window Above the list of layers are a few general control The opacity slider can be used to make the layer more or less transparent When the Keep Transparency toggle is off you can paint or otherwise modify the transparent sections of the layer If this toggle is on it is impossible to paint on the transparent regions Each layer is represented by a small thumbnail image To the left is an eye Clicking the eye will make a layer invisible Click again to restore the layer to visibility A layer can have a layer mask This is a grayscale image that can mask out parts of the image so that they are invisible or partly transparent This can be better than simply erasing part of the image because you can always edit the layer mask to change the visibility of any part of the image In fact a layer mask is essentially an alpha channel for the layer in editable form To add a layer mask to the image right click the layer s name and select Add Layer Mask from the pop up menu The layer mask appears as a new thumbnail next to the image thumbnail Layer masks can get confusing so pay attention Click the layer mask thumbnail if you want to edit the layer mask In this state any painting operation that you apply to the image window actually affects the layer mask rather than the image You will see the changes in the layer mask thumbnail Click back on the image thumbnail to edit the image Sometimes you want to see the layer without the effect of the layer mask Control click on the layer mask thumbnail to disable the layer mask You will see a red border around the layer mask thumbnail Control click again to turn the effect of the layer mask back on Sometimes you want to see the layer mask in place of the image Alt click the layer mask thumbnail to do this You will see a green border around the thumbnail Alt click the thumbnail again to see the image again Note that Alt click won t work in KDE unless you have configured KDE to ignore Alt clicks as described in the previous lab In the Layers Dialog shown here the Pasted Layer has a layer mask I have ALT clicked the layer mask thumbnail so that the image window would show the layer mask rather than the image The layer mask in this example is one used in the next project Winter To Spring Project Here is an image that I made by combining two photographs of the entrance to Hobart and William Smith Colleges one from the Colleges Web site taken in the Spring and one taken by me in the Winter The

    Original URL path: http://math.hws.edu/eck/cs324/s04/lab5/ (2016-02-07)
    Open archived version from archive

  • CPSC 324, Spring 2004, Lab 6
    display the image as it is being produced The image stays on the screen only while POV Ray is running After it is finished you can still use the display command to view it POV Ray produces a PNG image by default which as you know uses lossless compression and therefore doesn t lose any of the image s details But ray traced images are photo realistic and so the PNG images are rather large For posting on the Web you should prefer JPEG images Linux has a nice command line utility convert for converting graphics files from one format to another You can use it to convert starter png into a JPEG image with the command convert starter png starter jpg This makes a new file named starter jpg it does not delete starter png The Scene Description Language The main point of this lab is to use POV Ray s scene description One reason for doing it now is to give you some experience with thinking in terms of three dimensional coordinates Open starter pov in a text editor You will see that a POV Ray scene description looks a little bit like a C program For example comments in a pov file have the same syntax as C programs curly braces are used for grouping and the scene description starts with some include statements The file begins by including two files colors inc and textures inc These files define names that can be used in the scene description to represent certain colors and textures such as the color name White and the texture name PinkAlabaster All the standard include files can be found in the directory usr share povray 3 5 include so you can take a look at them if you like The remainder of the scene description consists of a sequence of object light camera specifications that set up the scene The first object is a camera camera location 3 3 6 look at 0 1 0 This shows the general format of object definitions The name of the type of object is stated camera in this case followed by the information needed to define the location size appearance etc of the object This information is enclosed between and In this case the information consists of the location of the camera and the point that it is looking at In POV Ray points are specified using angle brackets and so 5 10 3 would be the point with x coordinate 5 y coordinate 10 and z coordinate 3 The positive direction of the z axis points into the screen This is the opposite convention from OpenGL This means that negative z coordinates are in front of the screen and positive z coordinates are behind the screen The camera location 3 3 6 places the camera 3 units to the right of the center of the screen 3 units up and 6 units in front of the screen Following the camera two light sources are specified

    Original URL path: http://math.hws.edu/eck/cs324/s04/lab6/ (2016-02-07)
    Open archived version from archive

  • CPSC 324, Spring 2004, Lab 7
    cc This program shows a very simple wireframe car with the word CAR behind it You can rotate the scene using the arrow keys and the Home key If you press the A key an animation will start showing the car tumbling in space Stop the animation by pressing the A key again Exercise The exercise for the lab is to modify the program open gl wireframe starter cc to make it draw a different object Your object should be made up of at least six sub objects It should not be a car or anything too similar You could for example make a four legged table with a teapot on top Or make an airplane with body wings wheels and propellor You can do this work entirely inside the drawObjects function unless you decide that you need to change the projection or viewing transformations Furthermore you should modify the animation that is done by the program Instead of tumbling the object as a whole the animation should show parts of the object moving within the object For example you could have objects sliding around on top of the table or you could make the airplane wings flap or the

    Original URL path: http://math.hws.edu/eck/cs324/s04/lab7/ (2016-02-07)
    Open archived version from archive

  • CPSC 324, Spring 2004, Lab 8
    that is being tracked Suppose that you want a spotlight to shine directly on some object Select the spotlight by right clicking it Then SHIFT right click the object that you want the light to shine on This adds the object to the selection It is important that you do this in the right order The object that you right click first will track the object that you shift right click second Now hit CONTROL T This is the command for setting up a tracking relationship between two objects You will be asked to verify that you want to set up tracking This will make the spot light point at the object Whenever you move the object the light will turn to follow it If you animate the object the spotlight will follow the object as it moves If you try to make a camera track an object you will find that the camera rotates when you move the object but the camera doesn t point directly at the object This is because a camera starts out with some rotation already applied to it To make it point directly at the object you have to delete this extra rotation To do this select the camera by right clicking it and hit ALT R This is the command for resetting the rotation of an object to zero Once you do this the camera should point directly at the object that it is tracking You can clear tracking by selecting the object that is doing the tracking and hitting ALT T Sometimes you want to make a light or camera point at a position where there is no object You can achieve this by adding an empty object to the scene and setting the light or camera to track the empty object Add an empty object to the scene by using the Add Empty command It will appear as a set of xyz axes You can move an empty object just like any other object You can also animate it A nice trick is to animate an empty object that is being tracked by a camera or light Animation Blender is designed to do animations When working with animations you see only one frame at a time in the World Window Frames are numbered 1 2 3 Which frame is visible is controlled by the frames button as shown at right which just displays the current frame number It can be found at the top right end of the buttons window You can change the current frame with the arrow keys The left and right arrow keys move to the previous or to the next frame The up and down arrow keys increment and decrement the frame number by 10 Shift left arrow will return you to frame one You can also click and drag on the frames button to change the frame And perhaps most conveniently you chan shift click the frames button if you want to type in a particular frame number If you hit ALT A while the World Window is selected the frames will be played in sequence until you hit ESC To animate an object you just have to assign it different positions sizes and or rotations in different frames You don t have to assign a separate value for each frame If you assign a value for frame number 1 and frame number 30 for example Blender will interpolate values for frames 2 through 29 A frame to which you explicitely assign values is called a key frame and animation that uses key frames is called key frame animation You can have as many key frames as you want and each animated object can use different key frames if you want To set up a key frame for an object go to that frame using the frames button that was mentioned above Set up the object s size position and rotation as you want it to appear in that frame Then hit the I key The I stands for insert key frame You will see the pop up dialog shown at the right Just click on the type of data you want to animate If you are just animating the size of the object click Size If you are animating size position and orientation click LocRotSize The bottom entry in the menu is for animating the shape of an object in edit mode The Layer entry can be used to make an object appear or disappear by moving it from one layer to another assuming that one of those layers is not turned on Bonus Info Layers You can use layers to organize your work in blender These are not layers in the sense of being stacked up to make the final view Objects in different layers are all mixed together in the final image Layers in blender are used to organize your work You might set up your lights in one layer and your objects in another layer for example You can turn layers on and off using the group of 20 little buttons near the left end of a World Window Use a SHIFT click to activate more than one layer at a time You can also activate layers with CTRL 1 CTRL 2 etc or with SHIFT CTRL 1 SHIFT CTRL 2 etc to activate multiple layers To move an object to a particular layer select the object and hit the m key To have an animation you need at least two key frames so go to a different frame move or otherwise change the object and use the I key again to insert another key frame Once you ve done this you can use the arrow keys to move from frame to frame You should see the object s animation If you want more key frames just repeat the process Warning Once an object has been animated it gets is transformation from the animation data This transformation is applied every time the

    Original URL path: http://math.hws.edu/eck/cs324/s04/lab8/ (2016-02-07)
    Open archived version from archive

  • CPSC 324, Spring 2004, Lab 9
    four vertices around one of the quadrilaterals Then skip the next two vertices in the ring Then select another four vertices And so on Switch to a side view Keypad 3 and do the extrude Move the new vertices upwards about 1 unit Hold down the control key or click the middle mouse button to make sure the vertices are moved directly upwards with no sideways displacement Alternatively use the arrow keys to move the vertices instead of the mouse Rotate the view to see what you ve made if you want Now you should select just the original vertices in the ring This is easy to do with a box select in the side view Still working in the side view extrude them directly downwards five times After the second extrude scale the vertices down to make a smaller circle and after the fourth extrude scale them back up You have your rook Now you might wonder why my rook has nice smooth sides while yours is faceted If you use the Set Smooth button on the rook it will look really terrible because blender will try to smooth edges that should really look sharp For my rook I first turned on the Auto Smooth option in the Edit buttons and then hit Set Smooth Blender will then smooth only those faces that meet at a relatively small angle without trying to smooth the sharp edges between faces that meet at a large angle The cutoff angle is specified by the Degr button below the Auto Smooth button Unfortunately you will only see this smoothing in the final rendered image not in the preview and whether it works well depends on the exact shape of your rook the angles between the layers on the rook must be larger than the cut off angle To model a pawn you can use lathing Lathing refers to rotating a curve around a line to generate a surface of revolution Lathing in Blender is a touchy process and it is unlikely that you will memorize the exact steps that you need to go through If you want to make the pawn follow the steps carefully To begin start working in the top view Keypad 7 Hit SHIFT C which will move the 3D cursor to 0 0 0 It s important that the 3D cursor lie in the xy plane since we need to draw a curve that lies exactly in that plane Add a Bezier curve Extend it by selecting one endpoint and using CONTROL left mouse and shape it into half of the outline of a pawn something like the picture I used snap to grid SHIFT S to get the two endpoints exactly on the y axis select the endpoint hit SHIFT S and choose Sel Grid from the pop up menu to say that you want to snap the selected object to the grid This is also important To make the sharp corner at the bottom right I selected the control point there and hit the V key to make it into a corner We are going to spin this curve around the y axis to make the pawn Exit from edit mode Select the curve and hit ALT C You will be asked if you want to convert the curve into a mesh Confirm this This is important since lathing only works on meshes Now left click near the y axis and use snap cursor to grid SHIFT S again to make sure that the 3D cursor is exactly on the y axis The 3D cursor specifies the line that we will spin the curve around Select the curve and go back into edit mode Select all the vertices in the curve Switch to a front view Keypad 1 so that the y axis will be perpendicular to the screen and go to the Edit buttons Find the button labeled Spin In the row of buttons beneath the Spin button change the Degr to 360 and steps to 20 The 360 says you want to spin the curve in a complete circle The 20 says you want to make 20 copies of the curve as it spins Now you are ready to do the lathing Click the spin button If all has gone well you will now have a nicely shaped 3D pawn If you have more than one World Window then when you click the Spin button the cursor will change to a question mark and you will have to click on the World Window where you want to do the lathing There is one problem with lathing in blender You get an extra set of vertices at the final position and this can make an unsightly seam in the object To eliminate this in edit mode select all the vertices in the pawn Then click the Rem Doubles button in the Edit buttons This will remove the extra vertices by combining any pair of vertices that are very close together As a final step hit the Set Smooth button to give the pawn a smooth rather than faceted appearance This might work better if Auto Smooth is used I forgot to do this so the base of my pawn is not quite right That should do it As you can see lathing is a complicated affair but the results can be very nice SubSurfaces One cool feature of Blender is something it calls subsurfaces This feature uses a mesh object generally with a relatively small number of faces to establish the basic shape for a more nicely curved surface inside the mesh In effect the mesh acts as a set of control points for this surface and it s only the surface that is drawn The picture shows a subsurface inside the mesh object that defines it The picture is in Edit mode The vertices that define the mesh are only visible in Edit mode The mesh in this case was created by starting with a

    Original URL path: http://math.hws.edu/eck/cs324/s04/lab9/ (2016-02-07)
    Open archived version from archive

  • CPSC 324, Spring 2004, Lab 10
    setting Xrepeat to 5 five copies of the brick image are stretched across the wall rather than a single copy This makes the bricks five times smaller Earth Egg The image on the egg at the front left is home cs324 blender textures earth jpg This image is designed to be wrapped around a sphere or in this case a near spherical object You can find similar spherical projection images of other planets at http gw marketingden com planets planets html If you apply this object to a sphere or egg using the default settings it will look terrible The default for an image texture is simply to project it down onto the object This is called a flat projection It works great for a plane but not for a sphere and not for many 3D objects You can change the type of projection that is used for the image The change is made in the Material Buttons F5 not in the Texture Buttons Near the center of the Material Buttons window you will see buttons for the four texture projection types Flat Cube Tube and Sphere The Earth Egg was set to use Sphere projection by clicking the Sphe button The Cube projection projects 6 copies of the image from 6 directions and is suitable for use on a cube and some other 3D objects The Tube projection is similar to the Sphere projection but the north and south pole will look different After I applied the Earth image to the egg using spherical projection it was still not quite right the north pole was at the front of the egg instead of at the top To fix this I had to switch the axes used by the projection This is done with the X Y Z buttons shown in the above picture Marble Egg It is possible to apply multiple textures to the same object In the texture buttons you will see a set of eight buttons next to the texture preview Each of these represents a possible texture Click on one of these buttons to work on a particular texture For example to add a second texture click the second button and then create the second texture as usual In the picture the second texture is selected Some textures layer naturally A layered image texture on the other hand will simply cover up the image below it unless you make the image texture somewhat transparent We will see later how to do this For the marble egg at the front center I applied two different marble textures This layering works well because a marble texture simply adds some bands of color to the object It s possible to layer a second set of color bands on top of the first The basic egg color is very pale green The first marble texture layers a darker green on top of this It uses the Sharp and Soft Noise settings of the marble texture The second marble texture is an even darker green that uses the Sharper and Hard noise settings which gives narrower dark veins Remember that the way textures are applied is adjusted back in the Material Buttons The whole right hand side of the materials button window is devoted to these texture controls The eight buttons across the top of this picture select one of the eight possible textures that can be applied to an object Here two textures have been applied and the second texture is selected The other controls apply to this texture If you turn on the SepT toggle button at the top right you will only see the selected texture in the Materials preview if it is off you see the effect of all the textures The picture shows how I have adjusted one of the textures on the marble egg I have set sizeX sizeY and sizeZ to 2 00 These values affect the size of the texture but for technical reasons increasing the values of the size parameters actually decreases the size of the texture The size values actually act like the Xrepeat and Yrepeat values in the Texture buttons Next to the size buttons are the color controls for the texture here set to a very dark green You should understand how procedural textures like marble work The texture actually just assigns a value between 0 and 1 to each point on the object This value can be used in various ways but the default is to use it as a blending factor between the basic material color of the object and the secondary color that is set by the sliders shown in the picture above How the value is used is determined by the remaining texture controls on the right side of the above picture Note that I have clicked the Neg button above the color sliders This inverts the texture values so that 0 becomes 1 and 1 becomes 0 For my marble texture it switched the texture from narrow light bands on a dark background to narrow dark bands on a light background Wooden Egg The wooden egg back right was also created by applying two textures In this case two copies of the wood texture were used Both used the Band Noise option of the wood texture and for the second one I set the Turbulence to be rather high I also set the sizeY in the Material button for that texture to be 10 which squashed the texture down to give the small scale horizontal graininess on the egg Bumpy Purple Egg The purple egg is the first example of using a texture to affect something besides color In this case the texture was applied to the normal vectors of the surface The normal vector is used in lighting calculation to determine the direction in which the surface faces By varying the normal vector from point to point you can make the surface look bumpy Note that the geometry of the surface isn t

    Original URL path: http://math.hws.edu/eck/cs324/s04/lab10/ (2016-02-07)
    Open archived version from archive

  • CPSC 324, Spring 2004, Lab 11
    these out on the plane If Norm is positive and Rand is zero the particles will move straight up from the plane To see the animation easily go to frame 1 Shift Left Arrow then hold down the right arrow key Now if you change Rand to a positive value you will get a picture more like the one shown above If Rand is positive and Norm is zero you will get a cloud of particles To see the effect of Ob you will have to animate the plane Make it move from left to right between frames 0 and 100 You will also have to click the Recalc All button at the top of the particle system controls Otherwise Blender will not necessarily recalculate the particles motion to reflect the new animation You should use Recalc All to force a recalculation whenever you modify the emitter s animation The particles motion is automatically recalculated when you change any of the settings of the particle systems controls The Damp button adds friction That is it gives the rate at which moving particles slow down The X Y and Z Force buttons apply a force to each particle that that will gradually accelerate it in a given direction For example a negative Z force will act like gravity pulling the particles downwards An X force will act something like wind blowing the particles horizontally If Tex is non zero the velocity can be affected by a texture which can add effects such as turbulence but I haven t tried this You should try some of the velocity controls For example You can make a fountain if you use a negative Z force along with Norm Rand and perhaps Damp Try a moving emitter with high values for Ob and Damp and perhaps a negative Z force smoke coming out of a smokestack might behave like this Halos and Objects for Particle Systems The little white particles that you see in the 3D window are not visible in a rendered image However if you add a Halo material to the emitter then each particle will appear as a halo in the rendered image You can get various effects by using different settings for the halo properties The smoke shown in this image is a particle system with relatively few particles and rather large halos A Cloud texture is used as a HaloTex on the halos to give each halo some variation in color The texture just uses two slightly different shades of gray The animated version of this is pretty effective See smoke avi 950K The Blender file for this is home cs324 lab11 smoke blend This example uses material animation to improve the smoke effect As each particle ages it gets smaller This is accomplished by inserting animation keys for the HaloSize material property When you hit the I key in the Material button window this property is listed as HaSize in the menu You could also animate the color or transparency of the halos Note that the halo on each particle is animated separately over the lifetime of the particle For halo animations the frame number has a peculiar meaning Frame 1 corresponds to the beginning of the particle s life and frame number 100 corresponds to the end This is true no matter what the actual lifetime of the particle As an alternative to halos it is possible to place a duplicate of an object at each particle In the image particles are emitted from a large vertical plane located at the left There is a red cone at the position of each particle This is not very difficult to do Create the object that you want to duplicate Make that object a child of the emitter Right click the object shift right click the emitter press CONTROL P and confirm that you want to Make Parent Now select the emitter Go to the Animation buttons F9 Find the button named DupliVerts and click it You will see a duplicate of the object at each particle As noted in a previous lab DupliVerts can be used on any mesh not just on meshes being used as particle emitters one copy of the duplicated object is made for each vertex of the mesh An animation of the flying cones can be found in cones avi 1 7M In an alternative version cones with x force avi 1 3M I used a small initial velocity with a large force in the X direction to make it look like the cones were appearing on the left then accelerating rapidly to the right You can find the blender file in home cs324 lab11 cones blend For the cones example I subdivided the emitting plane several times so that cones would be emitted from more points on the plane However I still had the problem that the cones were emitted in a very regular pattern In a particle system the vertices of a mesh take turns emitting particles If the vertices are ordered in a regular pattern then the particles are emitted in the same pattern To fix this I randomized the order of the vertices Select the mesh go into edit mode and select all the vertices Go to the Edit buttons F9 Find the button named Hash and click it Bonus Info Generations of Particles A more advanced aspect of particle systems is the use of multiple generations of particles You are not required to know how this works When a particle reaches the end of its lifetime it can give birth to one or more new particles It is possible to assign a different material to each generation You can even have a third generation The picture is from a particle animation that uses two generations The emitter in this example is a mesh circle that is moved along curve by path animation dropping off particles as it goes About 1 4 of these particles will bloom at the ends of

    Original URL path: http://math.hws.edu/eck/cs324/s04/lab11/ (2016-02-07)
    Open archived version from archive