Hello! So, I’m making a vortex-like material in Unreal to use as a particle and I’m having some issues with the final result:
How can I get rid of these lines? I think the problem is in the texture I made for this, cause I can see some tones separation in the radial texture and Unreal smooth the hard edges in the texture.
Here’s the nodes:
try changing your texture to NoMipmaps
I think for this kind of effect you should use a mesh with radial uv coords. Similar to this this: Shannon McSheehan - LoL FX + Knowledge Share - #14 by ShannonBerke
Ok, the NoMipmaps worked and removed the excess. The line is still there, but it’s not perceptive. Thanks! 
Amazing thing, but I don’t know if I can set the Particle Mesh to always look to the camera. Is this possible?
Try setting your Screen Alignment under your REQUIRED tab in Cascade to “PSA Facing Camera Position”. This should work with meshes in addition to particle sprites
Dont set nomips. Never set no mips on anything other than very specific UI textures 
. Instead set the mipvaluemode on the texture sample to “derivative”, then take the UVs for your sprite before you rotate them and pass the derivitives into the sampler.
Sorry but, where can I read or study about these things? I don’t even know why you’re using DDX and DDY. Btw I suppose to use it in the 2Vector that modifies the UV Texture Sample or in the image with the distortion? Also got some errors here:
lol it’s kind of vague of my part showing this print
What’s the error say?
You can use VectorToRadial for UVs instead of a texture, then pan that at a few different speeds,
DDX, DDY are detailed here:
I’m getting the same error when I connect the nodes from the Texture Sample to anything in the Result Node
Hmm, the problem appears when I set the Mobile Stats on.
Well, it’s ok I guess. Thank you guys for the help
Sorry, old thread but very interesting stuff, do you know if this makes your material/FX significantly more expensive. or is it barely noticeable?
Hi guys. I wonder if someone has a good idea about preventing the very obvious center of polar-uv’s from appearing in the final result:
Here I add a radial gradient in combination with smoothstep but:
(a) this gives a center-area which is 1.0 and this means a gradient-map would not catch nice gradients to colorize the center. it would be only 1 constant color.
(b) the radial gradient is still noticable.
Does anyone has a better idea?
You could also have an additional texture for the center and blend it in I suppose, but that’s kinda the same idea.
You could add a second layer of movement, scaling up a texture with regular uvs, and crossfading back to the original scale, like we do with flowmaps
