He goes over the technique in the video quite well so i’m assuming you’re not super familiar with unreal 4 and you’re struggling with the execution?
basically i would start with setting up a mesh with a material on it that uses Parameters to gives you control over the type of effects he mentions in the video - mainly the Deformation and Alpha Erosion:
For the Deformation you just need to have a Noise Texture and use a Panner to move it over your mesh, then if you plug a Scalar Parameter into the Time value you’ll get something where different values gives you different shapes.
For the Alpha Erosion you again need to use a Noise Texture and a Scalar Parameter but this time add them together and the Clamp 0-1 and plug that into Opacity Mask (make sure you’re on the right blending mode.) Now if you input a value of 1 you get White everywhere, -1 you get Black everywhere, and nice random dissolving around the 0 input.
A noise pattern on a sphere, which can be done in several ways, Simon just suggests one possible option.
A dissolve / erosion / alpha test shader, which is as trivial as setting the material blend mode to Masked and adjusting the alpha value up and down by +/- ~0.5.
Some minor lighting adjustment to fake translucency. The talk says he used a small amount of emissive, which he looks to be changing based on the scene’s ambient lighting color. I haven’t worked with Unreal recently enough to know the best way to go about doing that.
So basically there’s two parts to how things are rendered in a game engine - firstly it draws all the vertex positions (the vertex shader) then it fills in those vert locations with pixels (the pixel or fragment shader) - some of the nodes can’t be used in both places (until DX11 you couldnt use a texture in the Vertex Shader for example) and that’s what this error is saying i believe.
I’ve done a quick test and it’s working for me though:
Thanks again for replying! I have no idea what I did wrong before, however I recreated the Material and it works fine now with the dynamic parameters woop! Now on the the particles system haha this should be funny
did you re-uv the mesh with a spherical wrap? or check that you have soft edges everywhere - you’ll get errors like this with either of those things (the vertex normals are split at hard edges and UV seam edges.)
you probably cant get rid of every seam but a spherical wrap should minimise it and you shouldnt be able to see it too much when its in motion and eroding etc.
Yes I definitely used a spherical wrap, but I haven’t checked the edges so I will take a look.
@simonschreibt thanks for the videos, your GAT#65 video on youtube was really interesting and has taught me a bunch of stuff… I also took on board the comment about imperfections being lost in the full effect, once I started spawning more meshes and putting the full behaviour together for the smoke, seams were lost in all of the activity very cool techniques man.
First Thank you for recording this and following up with the community. Great Work!
Second, I am working on learning the technique you explain @ 39:26 Could you explain a little further on the material set up for this moving threshold.
Third, I am having a difficult time to just have a mesh plane spawn in cascade that is always camera facing. I feel like I am going insane and the solution must be right in front of me. ( I am thinking of having the alpha erosion splashes play out on these planes) I assume that if they are not locked facing the camera, the look will break with strange volume losses on the splatter at different angles.
I familiar with this technique, his method seems even simpler. Lowering the values of the height map to get those drop shapes over time without extra masking using the masked blend mode. Maybe I am overthinking it, they could just be running it this way.