Search found 9 matches

by sebjf
Wed Aug 23, 2017 3:52 pm
Forum: General Bullet Physics Support and Feedback
Topic: What is the physics server?
Replies: 0
Views: 954

What is the physics server?

Hi, I want to use Bullet over the network. We have our own shared scene graph protocol. I am looking at the examples in Bullet 3, and see that there are a number of existing server applications, but can't find any documentation about them. 1. Is the new 'shared memory' api meant to be *the* api goin...
by sebjf
Sat Feb 25, 2017 7:02 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Damping oscillations in PBD?
Replies: 2
Views: 2343

Re: Damping oscillations in PBD?

Hi mobeen, It is my own framework. The system is very simple. The cloth particles are constrained with edge constraints. The solver performs weighted-averaging over projected positions similar to Weiler el al's Projective Fluids. The weights of the projected positions are scaled by an energy potenti...
by sebjf
Sat Feb 25, 2017 1:11 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Damping oscillations in PBD?
Replies: 2
Views: 2343

Damping oscillations in PBD?

Hi, In my PBD system, some of the particles are oscillating. I captured a few frames worth of the position buffers and put them into matlab to plot how the positions evolve over time and through the solve. The green lines connect each sample to the next in time. The plot looks a little odd on first ...
by sebjf
Fri Jan 06, 2017 11:31 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Trying to get a rough idea how many particles I can simulate
Replies: 2
Views: 2305

Re: Trying to get a rough idea how many particles I can simu

but I Just need a genera idea if this is something that would increase the processing by 100 fold or not. Short answer: no. Having first learned to program on an 8051, I still find it jarring when confronted with languages which 'do more' being as performant as those which run closer to the metal. ...
by sebjf
Tue Dec 27, 2016 11:11 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Suggestions for colliders passing between vertices?
Replies: 0
Views: 1578

Suggestions for colliders passing between vertices?

I am looking to handle the case where narrow colliders will pass between vertices of a low enough resolution mesh in a position based dynamics simulation system. So far the only technique that seems to address this is Fuhrmann et al .'s edge-center technique that was designed to handle trapped verti...
by sebjf
Fri Jul 01, 2016 7:43 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: How does the Strain Based Dynamics material transform work?
Replies: 6
Views: 3419

Re: How does the Strain Based Dynamics material transform wo

Hi mobeen, My thinking for the tangents went like this: The authors placed no constraints on the UVs, so we could say that uv1 = [1,0] and uv2 = [0,1]. This case would lead to the tangents being the edges of the triangle. The appendix says To make sure tu and tv are normal to each other, the latter ...
by sebjf
Thu Jun 30, 2016 9:28 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: How does the Strain Based Dynamics material transform work?
Replies: 6
Views: 3419

Re: How does the Strain Based Dynamics material transform wo

Thank you mobeen, That was helpful again! Now from our knowledge of triangles, we know that we can use a set of parameters (u,v or s,t) texture coordinates to linearly interpolate an attribute in the u,s (weft) and v,t(warp) direction on the triangle. OK I think I have this. So rather than thinking ...
by sebjf
Tue Jun 28, 2016 10:27 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: How does the Strain Based Dynamics material transform work?
Replies: 6
Views: 3419

Re: How does the Strain Based Dynamics material transform wo

Hi mobeen, Thank you very much, that was quite helpful. I have written an implementation of strain based dynamics chapter 12 in a new book Game Engine Gems 3 Yes I have a copy thank you :D - it was actually that book that helped me get this far! I have looked at others' source code, and it has helpe...
by sebjf
Mon Jun 27, 2016 9:59 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: How does the Strain Based Dynamics material transform work?
Replies: 6
Views: 3419

How does the Strain Based Dynamics material transform work?

Hi, I am working on an implementation of strain based dynamics, but am stuck understanding how one part of it operates. In Strain Based Dynamics a constraint is derived so that Green's Strain Tensor is a function of the relative locations of the points of a tetrahedron or triangle, and this then dri...