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Everything posted by anthonymcgrath

  1. when use houdini engine, alpha attribute problem

    Hi I'm not 100% sure with redshift I use vray in Maya as my char anim stuff is rendered there too. I export out my particles as alembic (promote to vertex before rop alembic export). In that export is my Cd and Alpha I bring in my particle sim from hou using the import proxy tool. I usually need to use a node to connect the Cd attribute to colour on my vray shader. I use a userdata node and enter Cd into that and then plug that into my shaders colour value. It's picked up. The same thing happens for my Alpha plugging a userdata node in and setting that to "Alpha" (capital A) Those are my main ones for my particles. I can also poop out pscale to control particle radius too There may be a similar option in redshift I heard it's very similar to vray.. Worth a bit of a twiddle to see what nodes are in there to do the job?
  2. okay so i've got a little issue here... I have FINALLY (After 30 hours of twiddling) got a really nice fairly stable sand grains anim going that interacts nicely with my char. so i've got my node network which is a basic off the shelf grains upres... i'm trying to wrap my head around whats happening in setseed_adjust_scale attribute wrangle node but i cant suss it out anyway what i want to do is vary the scale of my upres particles making some bigger and some smaller. so in my head i drop in a new attribute wrangle node (circled red in the pic) and i add the following: float @pscale = 1; @pscale = rand (0.002, 0.006); and BLAM! my pc fan after 30 seconds nearly ran out the window screaming!!!!! Its done this twice now and just locks up hou and the pc! so i'm properly stuck here - i cant figure out how to vary the scale of those upres particles - they are all the same size Anyone got any ideas on how to adjust this? ta ant
  3. Hey all ok I have a simple joint chain anim done in Maya.. 4 bones and a tube animating to bend the tube. I've imported it as fbx (merged into scene).. it all comes in as a subnet package with joints and skinned mesh. All looks good. So I've been testing the muscle sim and basically I'm connecting the muscle start and end points to joints in the subnet. Right now it seems to work fine.. joints animate.. muscles follow. However I now need to update the anim on the 4 joint system. This is easy enough Maya side.. animate.. export fbx.. job done. BUT.. now I want to replace the existing bones/skel animation data with the one from my new fbx. And I've no idea how to do that. Can anyone help here please? Id be a bit miffed if I need to keep reparenting all those muscle nodes each time an anim changes lol. Ta! Ant
  4. Hi yeah this is pretty cool and makes sense. So basically I would have my target skeleton at base pose and my animated skel.. and I transfer the anim to the target skel. The target skel will have extra stuff on it e.g. muscle sim perhaps. I've not much clue how to set that up in chops.. I imagine it's ok for one node but getting it to work with 100+ bones could be monotonous. Is there by documentation or tutorials for such a thing ?
  5. Hey guys can anyone offer any advice on this? It has to be possible surely? I've been banging my head in this.. if I can't replace an fbx things like like a muscle sim become a total nightmare to keep reconnecting

    can anyone tell me how to use this same trick with height in the mountain SOP please? I'm bashing my head off a wall here again - i figured i could adjust the wrangle for height instead of width but nope :/ sussed it - needed to plug a uv texture in with rows/columns.. pic for anyone interested! so with this setup my mountain node width is controlled to the middle part of the curve with falloff.
  7. creating chips WITH FLEX - fem sim vs grains vs rbd vs something else?

    yeah proper chuffed with this technique its going to come in very useful for a few things i want to do! yeah that geo source "second context geometry" isn't in v16 ...I added my path into the SOP path beneath it. The new option must be a 16.5 thing. gotta splat a load of ketchup and mustard over this burger and chips yet too hehehe. then a small sprig of leafy green garnish thanks again!
  8. hey chaps i'm trying to create a sim of some chips. I want a big heap of them to fall on top of a burger sim i've done! I've tried a few routes and just wondering what is the best way to go about this. I've attached a scene - its a basic setup of some chips model. I've made them packed and they fall. however they are rock solid and just clearly dont have an air of bendyness to them. what is the best way to go about this? I tried FEM ....making one chip... solid embed... multiple copies then run that. It seems to work in a fashion but soon as i turn up the amount of chips it becomes quite sluggish and also if some interpenetrate then you get wildly exploding meshes. I tried a wire solver but found the wires just seemed to do their own thing and not hold a shape or length. I have got the rbd packed working but of course its just simple shapes and they dont bend. I wondered if it might be possible to create a chip that comprises of maybe 5 simple boxes connected together with constraints? attached a scene file below - theres a fem setup in there and rbd packed.. chips_sim_v003_rbd_for_odforce.hip
  9. creating chips WITH FLEX - fem sim vs grains vs rbd vs something else?

    just posting a little pic so you can see the result - shaders and lighting need work but its on the right path
  10. creating chips WITH FLEX - fem sim vs grains vs rbd vs something else?

    omg it was actually a really simple fix - i just pointed the constraint network path to my primitive and they showed up with nice little cone guides too which i've never seen before working nicely as you can see below!!! thankyou so much for your help and advice - i'm still not 100% sure how you set this up but i'm starting to understand that ability to create your own constraint network with wires and lines - which i guess is what the glue network does overall but this gives much nicer control!
  11. creating chips WITH FLEX - fem sim vs grains vs rbd vs something else?

    hmm i'm still having issues here - is this a H16 vs H16.5 thing because i open that fix scene and it just does the same thing sadly the other thing is that i checked my dopnet and the constraint network and it is definitely plugged in as per your fix scene. I just had to set scale to zero on the primitive node but beyond that i honestly cant see any difference in that constraint network unless i'm doing something wrong? I'm so close to this and yet so far lol
  12. creating chips WITH FLEX - fem sim vs grains vs rbd vs something else?

    hey thanks for your help - this would be literally PERFECT for what i need wow thankyou except i'm getting a different result here (houdini 16)... its like my chips just seem to break apart and dont hold together like they do in your gif. I actually did a full rebuild of your scene and i've clicked all the stuff i need to but still getting this prob - any chance you can take a look at my scene and see where i went wrong please? :/ (I dont have 16.5 as yet if thats the issue ) chips_sim_v006.hip
  13. hi all i'm trying to add a way to rotate each of my pieces of my burger randomly - but i cannot suss it for love nor money can anyone help please? @mestela - i found a simple wrangle from you to shift all the pieces upwards (burger exported from maya!) ... now i just want to add a little rotation but i cant figure this out tried primitive wrangles and pasting expressions into transform nodes - no idea
  14. trying to roate pieces of my burger randomly

    hey thanks for the reply - this works and is quite fast... but the pivots for all the pieces seem to be at the bottom. i added a slider in to control the amount of rotation... you can see in this pic below that the pieces rotate from the origin. Anyway to centre the pivots on these pieces?
  15. trying to roate pieces of my burger randomly

    okay managed to get it sorted - seems to be something H16 is happy to do but 15.5 (which i was using) doesn't want to play ball. I also was given this cool tut by @Farmfield - cheers good sir!
  16. trying to roate pieces of my burger randomly

    was having some probs - my entire burger bun was rotating as one piece... keeps giving me an issue with the use of "-1" in that expression in the rotation channel. anyway just tried the exact same thing in H16 and it works fine... weird.
  17. trying to roate pieces of my burger randomly

    hey @Noobini thanks - this makes sense - but how did you add that seed and spare input parameter to the transform node? I was able to do edit intterface but cant find a spare parameter option or seed? edit - never mind - just did edit interface on your transform node in your scene and was able to find out what they were heh!
  18. trying to roate pieces of my burger randomly

    ah yes thankyou! yeah they are/were packed. I run a convert (to polys), transform to scale it down, drop in a normal sop and then i ran my connectivity/partition combo to get groups of primitives (are they called "details" ?) so: 400 primitives in _0 800 primitives in _1 962 primitives in _2 etc It would be great if i could just simply random rotate those primitive groups there.
  19. trying to roate pieces of my burger randomly

    hmmm not sure now - how do i know if my alembic is packed or not?
  20. so my thoughts are if i can sort each leaf so one point is the start and the other is the end i can get a line or a vector. then i can copy my leaf instance to this line Then i can use points 1 and 8 (in this pic above) to orient my leaf copy correctly (near as dammit) But no idea how to do that also each leaf has different point numbers - i need to figure out how to get each leaf to have the same point numbers?
  21. Hi all i've got a bit of a query here - i built a tree in speedtree and exported it to houdini to do a sim. I've got a tree trunk fracture, but i want to work on the leaves having them scattered now. the prob is when i separated out the leaves and try to run that through a sim it just died a death - prob because each leaf was unique. so my thought is if its possible to copy a leaf instance to each leaf - that way i can use packed geo potentially? I'm a bit lost here - i dont even know how to transfer one leaf onto the other leaf positions. i included my basic scene and the meshes - is anyone able to help me with this please? ta! ant tree_leaves.zip leaves_for_odf.hip
  22. so here are my leaves (scene file above) - each of these is a sep geo leaf... i tried throwing this into a sim and it blew up houdini i think... so i'm wondering if its possible to get one leaf and roate and translate it to the posiitions of others and use that leaf as a packed instance copy or something? i dont know how to edit and work with those polys or primitives - can anyone offer any advice please?
  23. Deform Object By Curve

    old post i know but i was banging my head against a wall till i found this thankyou
  24. tree destruction - getting that "bendyness" into it ?

    Hey thanks I didn't find this. I did a search on here but dunno how I missed this. I added a cone twist constraint into mine but it didn't appear to do much. I'll try what there suggesting with substeps and other values.. May get lucky!
  25. hey chaps, been a while since i was on here but i've been keeping myself busy! i'm having a little problem with my setup... i've got a tree (modelled in speedtree) and i've brought it into houdini. I've done a pre transform fracture to get 'splintery' pieces. I've set it up so a ball hits it (its a dragon in my scene but its quite heavy geo so dont want to include it!). now overall it 'works' ...as in the ball fractures the tree on impact. But its just lacking that splintery 'connected bendy' feel... eg if you load the sim and play it you'll see the lower half just kinda crumbles away... It would be nice for that to bend in the direction of the impact as if the tree itself is bendy - right now it feels like crumbling chunks of brick that all break apart - it would be nice to get some kind of bendyness in any branches that stay together? another thing is the pieces seem to lack some sort of 'inherit velocity' from the impact. I've followed a heap of tuts online but i just cant figure anything out - is anyone able to take a look at my scene (attached) and see if anything is possible? ta! ant scene included below - tree alembic also included.... i will shower you in MAOAMS sweetys if you can help me with this scene because i'm really lost tree_destruction.zip