Making Trail effect is easier now in Blender 4.0 | Geometry nodes tutorial

Hello friends in this video we are going to make this Trail effect in blender 4.0 because of its new node now let's me go to the viewport and delete everything first let me make a simple animated Cube and set the size to 1 M I want to give it animation in Geometry nodes so I'm going to use transform geometry and I want it to move in this direction so I type hash sign frame ided by 7 and also let me bring up the timeline and I also need to rotate this this Cube so type hash frame divided by 7 like this okay this will be my input from this point I'm going to make my trail effect first let me convert these two points mes to points Noe and yeah now in here I need to capture these points at each frame I mean for having the trail effect I need to capture these points at each frame and somehow join them together and then we want to have control over the data among the frames we can think about the simulation node so bringing the simulation Zone and now let me play it nothing happens because this simulation is getting the points from here at frame one and nothing is happening in here so it goes back at the next frame and nothing happens again and it comes back at the next frame and nothing happens so I will have this aesthetic points in here so for catching the points at each frame to have something like this I need to join these moving points at each frame to the previous points I mean the points in the previous frame so I can say join and now let me check that's it I have my trailing effect that's pretty simple just like this by the way in the previous tutorials I talked about the simulation in depths and details I'll put the link in the description and if you like you can check them and in The Next Step I'm going to connect these points with lines so there is a new node in here blender 4.0 which is points to Curves this node by default it is doing something like this it's connecting all the points together it's acting like this for example if these are my points with the index of 1 2 3 4 it will connect them like this by default so this is what we have as the result and I don't want that there's another option for this node it can also connect groups of Point together if I have some points like this I want to make two groups of these points and connect these points of the group to each other for this I should give all of these points a group of points actually a similar ID like all of them should have the ID of one also these points should have the ID of for example two they should only have similar IDs this node is actually connecting the points with similar IDs pretty simple so in here for example I have three points with the idea of 1 2 3 at the first frame and at the next frame they will come to here and they will be added to the previous points so I don't want them to have the idea of uh four five six I also want their ID to be like this 1 2 3 to be able to connect these points to each other right so at each frame before joining the new points to the previous points in here I should set their ID by their index number and after having that I can bringing the ID in here and after connecting this ID to this node it will connect the points with the similar IDs now let me play it from beginning yes you can see I have my trail effect and also if you want to trim the end of these curves like in here if you want these points to fade at the end at a certain amount of time we should Define AG attributes for them so I can say capture attribute and set it to integer because I want to Define age by the past frames and before connecting this to here I should add this by one because I want the age to grow during each frame by one now that I have my age I can say when the age is greater than this is a compare node which gives me the control for selecting points so in here I said when the a input is greater than my specified value like 20 the result will be true it means in here the points with the AG greater than 20 will be selected to be deleted I'm using delete geometry in here and give it to the selection now let me check it yes they are being deleted but 20 is a constant number and I want some random numbers for having more pleasant effect so I use random number random value and set it to integer like between 30 and 50 check it again yes I can convert it to line like this right beautiful now after that I'm going to convert this line to mesh so to mesh curve to M note um I need also a curve Circle filling the Caps you can see although the radius in here is 1 M but this is so small that's because of this uh mesh to points note the radius in here is 05 and for having the real number in here I'm going to change the radius curve set curve radius and set it to one now I have my real number in here I can set it to like 02 and the resolution is too much six is enough I think at the end of this explaines I need the radius to be about zero actually the both ends of this curve so I'm going to use the spline parameters it has a factor well each curve has a factor of 0 to one and by this I can have control over my spline and play with it so I want to connect this factor to the color ramp and connect this to the radius now you can see when the factor is one the radius is one and when the factor is zero the radius is zero also want to do this for the both ends so something like this nice and At Last Of course of course you can set the material for it and yeah that's our Trail effect you can in here connect any kind of animated objects to this input so in the next part I'm going to import my character and like this I want to select some points manually on this mesh to have the track of them okay in here here is my character and I want to hide the cube first and I want to select some points on this character I'm going to select the mesh and add a Vertex group in here and call it Trail after that I should go to the edit mode and select some points which I already selected some of them okay after having them selected and also this Trail is selected I should press assign to make my trail vertex group and here is the animation of it okay I'm going to unhide the cube in here and in this Cube uh I should bring in the character mesh instead of using this Cube object I want to use the cube as as my trail object so I can bring the mesh the character machine here set it to relative and connect this to this input but if I just simply connect this to input it will convert this node will convert all of the all of the mesh to the points like this and let me turn off the amature let me reduce use the size of it you see it is just showing all of the points but I only want my selected Point group the trail so I can say name attribute and in this name attribute I should type my vertex group name Trail and since a Vertex group is a selection of the point I should connect this attribute to the selection now here they are the points the selected points let's go to the animation and also turn this off again okay I I don't want this fading effect in here I want to mute this Noe and again okay these curs are a little bit thick I want to reduce this to like 0025 okay so thin now but first let me show you something you can see that they are not so smooth and look little bit Jagged that's because of the low frame rate I should before converting these curves to mesh I should change this spine type to nerves so I use say the spine type node and change this to nerves now you can see there are so much rounded and beautiful in the Shader editor uh for having this effect I gave it um the geometry nodes the tangent in the emission I gave it the tangent to the color of the emission and set the strings to something like 10 okay and also for having a b better control over the radius you can say group input and simply connect this radius to the input and you can have control over this in here 025 right beautiful it's like this also for having this a ha effect you can just simply turn on the motion blur and I rendered this with cycles and please keep in your mind that when you want to render your animated object you should make sure that you are caching your animation especially when you have motion BL at least to one frame more than your render frame to make sure have a nice motion and yeah I think that's it and that was pretty easy the main part of this trailing effect was these few nodes and also this one I hope you enjoyed the video and wish you all peace

Channel: Blender Path

Views: 7,508

Keywords: blender, blender 4.0, simulation node, geometry nodes, blender tutorial, tutorial, simulation tutorial, geometry nodes tutorial, beginner

Id: Ir1qGy5ycdA

Length: 15min 30sec (930 seconds)

Published: Fri Oct 13 2023