MotionTrail3D: Sword Trail Tutorial

Dialogue: This tutorial is for those who wanna make a sword trail effect. I use my motion trail addon to create the mesh from animation, but it’s only a convenience. If you wanna follow along, go download the Sword Trail Material. It’s Free to Download. The nodes will not be explained in this video, only how to use it. First, we can use the motion trail to create a mesh from the animation. We create the first tracker point at the tip, the second at the base. Then go to the Tracker Points panel and click on the “Mesh From Tracking Points“ button. Exit the motion trail. Now, both meshes have a vertex per frame. Join the two meshes. To smooth it out, convert to Curves. Set the spline type to Bezier and Handle types to Free. You can modify the handles to smooth out the trail. Be careful not to change the location of the main Co controls since that’ll change the length of the trail. Auto handles also works pretty well if you don’t want to smooth it out manually. When its all good, remember the resolution value of the curve. Mine is set to 16. Now convert the curve to Mesh. Go to edit mode, select all vertices and Bridge Edge Loops to create the faces. Notice that there are now 16 faces per frame. Onto the UVs. Select the first Face. Reset it’s texture coords. Go into the UV editor, set the pivot to bounding box, and flip the coords across the X axis. Keeping the first face as the active selection, then select the rest of the faces. UV unwrap using “Follow Active Quads“ so the rest of the faces to follow the first Face and account for it’s flipped UV’s. Be sure edge length mode is set to Even so all UV’s are the same size. Recall the Bezier “Resolution Preview U“ value. That determines the number of faces created per Sword Trail Frame. So, we have to scale the UVs by that number. In my case, the resolution was 16, so I scale by 1/16th from the origin. Finally, set the material to the Sword Trail Material. On the Sword Trail Node, Key “Current Frame“ at the start and end frames, set the interpolation type to Linear with Linear Extrapolation. Set “Frame Start“ and “Frame End“ to match the range trail. In the texture node, make sure it’s set to the gradient texture or whatever sword trail texture you have. The right side of the texture leads the trail. Done. Now you have a sword trail. If you prefer to have a focal frame for the sword trail, I’ve made an alternative sword trail node. Everythings the same. There’s just 3 added properties. Set the brightest frame along with darkest frames. If your texture is a gradient, you can use the output UV based Alpha as the UVs for the texture node. You can change the Trail Tail Size to change the duration of the trail, in Frames. __ sword trail material: more info: get: more animation addons: twitter: __ MotionTrail3D allows you to author arcs in 3D world space. The 3D-controls are implemented as normal Blender objects. They’re selectable and transformable through normal Blender means. Keys can also be added and deleted through normal Blender means. As you modify the local channels, the 3D trail will also update in real time, even if the animation is playing.