Hello, i was wondering if someone could help me with a physic tool issue im having.
So my issue is this. If I try to add physics animation to my custom models, they just explode all over the place. It works if i just use a cube and run the same comands in keyshot.
So i can make it work like this:
But when i try to import my own shapes it all goes a bit wrong:
Anyone had this issue and would be able to help?
Thanks in advance!
Luke
It looks like you have a number of hearts layered on each other, which are then patterned into 25 stacks, is that right? If that’s the case, make sure that each stack has some space between each heart. I think that if they are overlapping you can get this result, as they collide and has to move away from each other, which can happen fast. I’m not sure but I would assume that if they are layered in another software, with mates in a CAD software for example, Keyshot might still consider them as overlapping.
If that’s not the case I’m not sure I can help, but I do know that the bounding box of models can cause issues sometimes if it doesn’t match the look of the model. I’m not sure if it affects the physics sim though. I think there’s a display mode that shows the bounding box of models, might be worth checking out just to rule it out.
Good luck!
Joakim mentioned the right way. But before, I would recalculate the normals of the part and check the normal direction. Then let this one part fall (You can try to use max gravity factor of 200). If this one part falls correct, the pattern this part and re-run the physics simulation.
Can confirm that this would be a bounding box issue. In other apps (cineme 4d) you can choose to use the bounding box for the sim, or the mesh itself. The mesh method just takes way longer to calculate than the bounding box method. Marco has the right way, try one instance of the heart then expand to more and more until you get the effect you want. Its a way of troubleshooting what the problen really is. Most of the time this behavior is due to overlapping meshes or in this case the bounding box that is being used for the sim.
Hey guys thanks for your help, I will spend this evening seeing if I can get it to work. The bounding box makes sense to me so will try that first and let you know the results
Still no luck, could it be a issue that im importing from Rhino straight into Keyshot, the heart ever just drops straight down with no movement or explodes!
for sure try to export as any other file, fbx, obj and see what happens.
I’m not sure what you mean with ‘no movement’. If you just have one heart it will just fall straight since there is no way in KeyShot to give it an impulse other than the gravity what pulls on an object. So if you’ve only one heart which drops it will just go straight downwards in the actual position.
Like I said, not sure if I understand you correctly. What I once to get some diamonds tumbling down instead of dropping straight was to fix a simple construction with a few cylinders so they collided with those on the way down giving it a more natural effect.
Anyway, not sure if it helps you but this is the construction I made
sorry, for the late reply, this was starting to get the better of me so stopped for a while! Your video is showing what i want to achieve, but the model just explodes as my previous video i posted. I tried using a modeled funnel to let them flow down a channel but the same thing keeps happening.
Are you using your 3D software to link with keyshot? Or are you just importing straight into Keyshot.
Ok so ive broken it down into indvidual sections, it appears that as soon as a collison happens the parts scatter wildly instead of making a nice pile of hearts on the floor, which is my desired outcome. In these gifs you can see that as soon as they touch the issue happens:
First Test 1 Heart:
Second Test 2 Hearts:
Third Test 4 Hearts:
Forth Test 5 Hearts:
As soon as the 5th heart is added to the physic sim, which means that there is a collision it shoots off widly in any direction.
The model of the heart is imported as an .stl then in keyshot made into a pattern.
Could there be a reason that the settings are off, because also i notice that with the physic test done with a cube created in keyshot the animation is alot smoother as shown in the cube gif below. No default settings have been changed from cubes to hearts.
Clearly there is somthing wrong with my gemometry which is made in Rhino3D, but ive no idea what!
Hope this explains well enough my situation.
One more test, so I created a cube in rhino which is red, a cube in keyshot which is blue, and then imported a different custom model from Rhino3D:
Hi @luke.orford,
I can imagine it can be a little frustrating if it doesn’t really work. But I think you’re getting closer. What I did with the dropping diamonds was really slow down the entire animation. I might even have a screenshot somewhere of my settings but not sure.
So basically you don’t let the gravity pull like it normally does (the 9.something). This gives also more steps to calculate so the calculation itself will be much slower but more detailed. At least, I think it works a bit like that. It gets more precise and with enough rendered frames you can always speed up in post.
I didn’t use any link to other software. I did actually the same as you did. I did use normal polygon models so it might also help to convert the NURBS models to polygon models in KeyShot. I’m not sure if that has an impact but I think it needs some kind of bounding box for the collisions and that box will be polygons anyway.
As I mentioned, the settings are really important and I remember I really had to test a lot to get the diamonds not bounce off the cylinders as well. It’s bit late in Dutchieland so I’m off to bed but I can check if I somewhere saved the settings I used in the end. I often do so when I puzzled for a long time but not sure.
Maybe you already get far by really lowering the gravity to something like 0.1 or so. If you want you may also upload your scene to f.e. wetransfer.com and I can check tomorrow morning if I can figure something out.
Ah well that really is a bounding box issue I think. The cute fishes have a pretty hard shape to calculate while the boxes are way easier, it will just use a box collider which makes calculations super simple. I see there’s a bit of difference with the red cubes and the KS ones but it’s not that big. Not sure how it will tesselate the cube from Rhino.
The hearts though are a more simple shape than this fish so I think that if you give it more calculation time it can help a lot. Don’t have KS open now but there was also some kind of precision slider but sometimes it gave me a bit of opposite results of what I expected.
Thanks for the response, im gonna keep on working on it, tweek the settings more, hopefully get some changes!
Thanks for all your help! Hopefully tomorow you will see something awesome!
heres the final test for this evening, lowered the gravity to 0.1 its definatley changed the outcome but still having the same issue!
I haven’t done tons with this tool, but could it have anything to do with scale or some other settings?
Also, I never work with STL files… I believe Rhino can export STEP. Can you give that a try? If not, can you use the ‘simplify geometry’ tool in KeyShot to make sure there’s not some other issue in the geo coming in from Rhino like an artifact that’s too small to see?
Finally, can you simplify and just do a single stack of say 10 pieces? See if that has a different outcome?
Will has a good point about the scale. I just loaded that diamond scene and I see I’ve scaled it 10x a single diamond is now like 16mm.
I also noticed it remembered the settings I used for the physics simulation and here they are:
To be sure I deleted the existing animation but this seemed to work really well in my scene.
The suggestion to use ‘simplify mesh’ is also a good one. You can do it before you create the pattern and if you do it after creating the pattern be sure to not ‘right click > simplify mesh’ but use the button ‘tools > simplify mesh’. If you would use the right click version it will deselect all but one which doesn’t make any sense but it does.
Ok here are some tests:
The model has been directly imported via Rhino3D
1: Deafult Settings not changing anything:
2: Simplify heart geometry in keyshot, gravity at 0.1
3: Simplify heart geometry in keyshot, All settings the same as Oscars.
so using settings from the 3rd test, i went big, unfortunatley we are back at square one!
Try the last one again but without putting in other settings first. I’ve sometimes the feeling it caches certain things. They also fall much faster it seems than it shows at the 3rd example.
And again, if you like I can try to fix the scene if you want.
