Differential Mesh Growth - The Quick Way

[@komaz67]

how would u extend this concept to animated geometry?

[@artofnick]

The group doesn't have group by expression in it anymore. Using a group expression node doesn't work because of possibly an hscript / vex issue. I'm not sure what to do here.

[@b105cz]

The problem seems to be in the Smooth node, because it looks for a primitive group, not point group. The walk-around is to switch the operation expression from < to > (@pscale < 0.005). Now you have the point group that is not going to be smoothed. Then in the Smooth node, leave the Group blank, but set it in the Constrained points as group1.

[@pereriand8778]

Hey there! This is awesome! Is a differential growth with collision/obstacle handling possible? It would be great if the differential growth could dynamically grow around objects.

[@cosmosunited]

So nice. Mine grows everywhere, it's not emitting from a single point, I don't know why. I'm planning to use this as a model for landscape deformation with custom textures instead of noise. Would that be possible?

[@twodumbocreatives2627]

Hi, I used your method get up to 6:57 where you introduced group sop and add the expression as @pscale > 0.005, but there is no such 'group by expression' option for operation within my group node, and my result turned out as a chaos, apparently I see my group node settings not exactly the same as yours, is it because of different versions? And if I don't have this group by expression option with that VEXpression @pscale > 0.005, are there ways or nodes to do the same thing to achieve the same result that can replace group node?

[@twodumbocreatives2627]

I only have learned Houdini less than half a year, really looking forward to your reply and help

[@charlesnyiha4641]

Two Dumbo Creatives The Group nodes changed in Houdini 16. There is a separate Group by Expression node now. You can use that.

[@twodumbocreatives2627]

@@charlesnyiha4641 thanks!

[@isoutoforbit]

@@charlesnyiha4641 I'm new too, I can only see GroupExpression, not Group by Expression, and it looks very different, so I can't follow from there :/ any advice?

[@noisenoise9600]

@@isoutoforbit A bit late but I managed to create a work around: Add the Group Expression node, group type = points, | group = group1 | vexpression = '@pscale > 0.001' now create an attribute promote, original name = pscale | original class = points | new class = primitive now copy the first group expression node and put it under the attribute promote, all you have to change is group type = primitives Now add a smooth node, group = group1 and now it should work without errors. The reason you have to do this workaround (at least for me) is because the @pscale expression somehow wont work when the first group expression node is set to primitives, and the smooth node will just smooth the entire mesh. By first selecting the points with the first group expression, then promoting those points to primites, you can then select those primitives with a second group expression thats set to primitives, which the smooth node now accepts. Hopefully this is a good workaround, as i've been only using houdini for about 1 to 1,5 months now, but it seemed to work for me :)

[@excessoats]

How would I preserve the uv map on the parts that aren't receiving the growth?

[@hutchinsonpatrick]

Would love to know this also, have you had any success?

[@dottormaelstrom]

You could calculate them at the beginning separately and then use an attribute transfer on the mesh after it's been processed maybe

[@hutchinsonpatrick]

@@dottormaelstrom ay thanks!

[@dottormaelstrom]

@@hutchinsonpatrick let me know if that works, I'm a total beginner, that was just the first thing I thought!

[@zakirali8721]

what sorcery is this !@🤯 . im new to houdini . this is so cool

[@alexgithiora6228]

awesome tut but why do you guys use H15

[@Entagma]

This is an oooold tut. Like 2016 old. Cheers, Mo

[@yhi228]

Hi, is it possible to use audio for the noise input?

[@Entagma]

Yes, you could do that using CHOPs. Cheers, Mo

[@uzaykisi1863]

Please tell me or advise a tutorial to render it in redshift? As in your example

[@Entagma]

Hey hey, we've got a whole premium course on rendering here: entagma.com/courses/rendering-101/

[@JohnDowson100]

Super interesting result! Is the workflow still the same in 19.5 or has it been updated? 😀

[@fuckingdrummachinez]

pretty much the same

[@shmuelisrl]

In the line differential growth you did collisions over here you didn't.

[@LightninK1ng]

Can you please remake this in blender

[@animationspace8550]

Can you guys do more stuff on differential growth? Found this cool video and got inspired by it all: kzbin.info/www/bejne/b3msaXmbp7ClbLM

[@DOVEDELS]

It's a great tutorial you made here, but when I start the simulation it just starts to smoothen whole mesh. Im a beginner with Houdini btw😅

[@DOVEDELS]

Maybe it's because I started this with not a Houdini generated geometry, but imported my own fbx. file and then subdivided it? I'm on H18 BTW.

[@aw_artwebanimation]

@@DOVEDELS No same thing is happening to me with houdinis geo!

[@Thimer132]

Make sure that inside solver you are putting pointvop and Input_2 (not Input_1!) into attributetransfer.

[@jihadakoury7442]

Super late to the party, but this might help someone someday. When he switches the group type inside the solver from Points to Primitives it clears the selection, because it is looking for a pscale attribute at primitive level which does not exist. And therefore the smooth SOP later will apply to the entire mesh. Instead keep the group type at "Points" and add a groupPromote node after and convert the already existing group from Points to Primitives

[@nikolaykirchev9672]

@@jihadakoury7442 I love you