violalyu 10 Posted November 12, 2016 Hi Houdini friends, Does anyone know how to use mask field in DOP net? I'm doing a simulation of leaves on the ground reacting to a car passing by. I need to control the wind force to affect only where the car is passing, where other leaves remains more still. Is there any way to mask out the affected area and have the wind force only affect that area and have dynamic change on the mask object? Or if there's other ways to do this? Thank you so much!!! Share this post Link to post Share on other sites
fencer 183 Posted November 12, 2016 check DOP_mask_field.hip 1 1 Share this post Link to post Share on other sites
Atom 1,208 Posted November 12, 2016 Cool, that is a nice example file. You can also plug the mask in to gravity, reverse the gravity direction and have particles rise up only when the box passes through them. Share this post Link to post Share on other sites
violalyu 10 Posted November 12, 2016 4 hours ago, fencer said: check DOP_mask_field.hip Thanks Fencer! I've checked the file, I'll see if this setup will work in mine too! Share this post Link to post Share on other sites
violalyu 10 Posted November 12, 2016 3 hours ago, Atom said: Cool, that is a nice example file. You can also plug the mask in to gravity, reverse the gravity direction and have particles rise up only when the box passes through them. Thanks Atom, that's a nice idea! Share this post Link to post Share on other sites
violalyu 10 Posted November 13, 2016 On 11/12/2016 at 8:44 AM, fencer said: check DOP_mask_field.hip Hi fencer, I have another problem of this. After the leaves rise up they need to be not affected by the force anymore, but this method it continue to affect the leaves, so they never fall on the ground again. Is there any solution to that? Thanks!!! Share this post Link to post Share on other sites
Atom 1,208 Posted November 13, 2016 (edited) It seems to work for me, there is a gravity force following the wind. You do have to play with the numbers on the Wind Force. This GIF shows the windforce adjusted so the Scale Force is 6, was 60 and the Velocity in the Y-AXIS is 10, was 1. So the overall force is similar, 6 * 10 i.e. 60 but it is split between the input channels in a different way. Edited November 13, 2016 by Atom Share this post Link to post Share on other sites
violalyu 10 Posted November 13, 2016 33 minutes ago, Atom said: It seems to work for me, there is a gravity force following the wind. You do have to play with the numbers on the Wind Force. This GIF shows the windforce adjusted so the Scale Force is 6, was 60 and the Velocity in the Y-AXIS is 10, was 1. So the overall force is similar, 6 * 10 i.e. 60 but it is split between the input channels in a different way. Thanks Atom! I'll try this! Share this post Link to post Share on other sites
JDee 12 Posted December 15, 2016 (edited) Hey guys I'm trying to modify the fencer hip example by adding some noise into the box volume, so what I need is to make kind of noisy shape of the mask to affect the particles I simply put volumevop with some noise after the isooffset but all the setup is not working this way, the particles start moving out of the box mask. Does Sop Scalar Field allows me to do it basically ? thanks Edited December 15, 2016 by JDee Share this post Link to post Share on other sites
fencer 183 Posted December 15, 2016 25 minutes ago, JDee said: Hey guys I'm trying to modify the fencer hip example by adding some noise into the box volume, so what I need is to make kind of noisy shape of the mask to affect the particles I simply put volumevop with some noise after the isooffset but all the setup is not working this way, the particles start moving out of the box mask. Does Sop Scalar Field allows me to do it basically ? thanks DOP_mask_field_v02.hip 1 Share this post Link to post Share on other sites
carloshs93 1 Posted March 11, 2020 Still works on 2020 17.5 ;D thanks from the future 1 Share this post Link to post Share on other sites
Dubtronics 2 Posted May 28, 2020 Thanks guys this was really handy, I was also wondering how can we mask forces by other attributes. Say you wanted gravity only on particles that had reached a certain velocity. Share this post Link to post Share on other sites
oaschwab 1 Posted September 11, 2020 Is there a way to blur the mask so that it has a soft falloff? Share this post Link to post Share on other sites
fencer 183 Posted October 5, 2020 On 2020-09-10 at 6:52 PM, oaschwab said: Is there a way to blur the mask so that it has a soft falloff? Sure, just multiply input volume values. Make gradien 0 to 1. Share this post Link to post Share on other sites