It seems that the path C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\Hostx86\x64 is a path found in VS 2017. Does anyone know if VS 2017 should be used to build plug-ins for Houdini 17 ? As far as I can tell, VS 2015 should still be the correct version…

Hi everyone
I am trying to build a custom HDK plug-in for Houdini 17 but I can't get it to work even though I have been able to do this for earlier versions of Houdini without problems using both cmake and hcustom following the instructions in the HDK docs and setting the MSVCDir.

I have also tried to build the SOP_Star example using cmake but the plug-ins wont load in Houdini even though the solutions seem to build just fine without error. The plug-in is not visible within Houdini.

I use Visual Studio 2015 with update 3 and Houdini 17.0.459 .

I have also tried to use hcustom, but then I get this error:

Failed to run C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\Hostx86\x64\cl with error 2: The system cannot find the file specified.

This path does not seems to exist but when I use cmake it targets this dir:

CProgram Files (x86)/Microsoft Visual Studio 14.0/VC/bin/x86_amd64/cl.exe

And creates the solution which builds just fine in VS.

Any help would be greatly appreciated

Hi everyone

I'm trying to write a DOP with the HDK and I want to implement collisions. So to do that I need to get the attached collision geometry data. My question is: How could I get a list of collision geometries with the HDK from within a DOP solver ?

I have looked in the documentation but to no avail so far. The closest thing I have found is the implemnetation of constraints but I have not been able to figure out how to use this for collisions so any help would be greatly appreciated

Hi everyone

I was wondering if it is possible to iterate over fields and geometry at the same time using the openCL gas solver. I know it is possible in SOPs where you can merge geometry and volumes, and then get thread id's for both the voxels and points, but in DOPs you seem to be stuck on one or the other. I can't get id's for both voxels and points.

Alternatively i thought about using a SOP solver with an openCL node inside, but will the data be copied back to the CPU at each time step in this case, or will it stay in GPU memory ? If the data goes back and forth it kind of defeats the whole purpose…

BTW. I used hcustom to compile

Hi everyone

I wrote a HDK plug-in for Houdini 15.5.673 which works in that version but I can't compile it in Houdini 16.0.600. It throws all sorts of errors. I have updated the libraries and can't detect any errors in the code itself, so I tried to compile one of the sample files and that did not work either. Any ideas ? The errors look like this:



CPROGRA~1/SIDEEF~1/HOUDIN~1.600/toolkit/include\UT/UT_PageArray.h(751): error C2143: syntax error: missing ‘;’ before ‘&’
CPROGRA~1/SIDEEF~1/HOUDIN~1.600/toolkit/include\UT/UT_PageArray.h(726): note: see reference to function template instantiation ‘void UT_PageArray<DATA_T,0x03,true,false,0x0a,GA_Offset>:pVector<1,float,0x03,false>(IDX_T,const UT_FixedVector<float,0x03,false> &)’ being compiled
with
[
DATA_T=float,
IDX_T=GA_Offset
]
CPROGRA~1/SIDEEF~1/HOUDIN~1.600/toolkit/include\UT/UT_PageArray.h(726): note: see reference to function template instantiation ‘void UT_PageArray<DATA_T,0x03,true,false,0x0a,GA_Offset>:pVector<1,float,0x03,false>(IDX_T,const UT_FixedVector<float,0x03,false> &)’ being compiled
with
[
DATA_T=float,
IDX_T=GA_Offset
]
c:\program files\side effects software\houdini 16.0.600\toolkit\include\ga\GA_Handle.h(396): note: see reference to function template instantiation ‘void UT_PageArray<DATA_T,0x03,true,false,0x0a,GA_Offset>::addVector<float,0x03,false>(IDX_T,const UT_FixedVector<float,0x03,false> &)’ being compiled
with
[
DATA_T=float,
IDX_T=GA_Offset
]
c:\program files\side effects software\houdini 16.0.600\toolkit\include\ga\GA_Handle.h(396): note: see reference to function template instantiation ‘void UT_PageArray<DATA_T,0x03,true,false,0x0a,GA_Offset>::addVector<float,0x03,false>(IDX_T,const UT_FixedVector<float,0x03,false> &)’ being compiled
with
[
DATA_T=float,
IDX_T=GA_Offset
]
c:\program files\side effects software\houdini 16.0.600\toolkit\include\ga\GA_Handle.h(390): note: while compiling class template member function ‘void GA_RWHandleT<UT_Vector3F,void>::add(GA_Offset,const T &) const’
with
[
T=UT_Vector3F
]
c:\program files\side effects software\houdini 16.0.600\toolkit\include\ga\GA_Detail.h(228): note: see reference to function template instantiation ‘void GA_RWHandleT<UT_Vector3F,void>::add(GA_Offset,const T &) const’ being compiled
with
[
T=UT_Vector3F
]
c:\program files\side effects software\houdini 16.0.600\toolkit\include\ga\GA_Detail.h(2333): note: see reference to class template instantiation ‘GA_RWHandleT<UT_Vector3F,void>’ being compiled
CPROGRA~1/SIDEEF~1/HOUDIN~1.600/toolkit/include\UT/UT_PageArray.h(751): error C2461: ‘UT_PageArray<DATA_T,0x03,true,false,0x0a,GA_Offset>:pVector::<lambda_47ea463578c9571ff4fab648d63ab596>’: constructor syntax missing formal parameters
with
[
DATA_T=float
]

Hi everyone

I am trying to print out the entries of a sparse matrix in the HDK but no luck so far. I created a UT_SparseMatrix and tried to use printFull() like So:

UT_SparseMatrix elm(16, 16);
std:stream stream();
elm.printFull(stream());

I have tried to include <iostream> , <sstream> and <ostream>, and <UT/UT_SparseMatrix.h> of course, but when i try to compile it with hcustom it complains about unresolved externals. Any ideas ?

I am pretty new to the HDK so this might be a complete noob question

Hi everyone.

I need to do some low level changes to Houdini's finite element solver for a project I am working on. So I need to get at the source code for the finite element solver DOP, in particular the source code or functions where the stiffness matrix is assembled and inverted. So far I have not been able to find the correct directory but it must happen in there somewhere. Could anyone point me to the correct path in the Houdini directories ? Any help would be greatly appreciated

Thanks so much matthias_k It works perfectly ! It was the attribute rename sop I was missing. And you do have to use a reverse sop at the end to flip the ptex. Awesome

Here is the result in Houdini btw …

Maybe this could help. It should work in indie with renderman installed. I applied a test ptexture to a generic mudbox sphere. The jpeg image is how it should look. It definitely seems as though the ptexture is getting tiled pr polygon so I am almost certain that missing face indices are to blame for the problem. But I have not found a way to apply them in Houdini.

Hello everyone

I have encountered a few problems when transferring ptex textures from Mudbox into Houdini. I am using Renderman in Houdini, but loading ptex textures through a pxrptexture node into the diffuse channel of a BxDF yields weird results. The textures seems to be tiled so my guess is that something is wrong with the face id's.

I simply exported the geometry from mudbox as an obj. file along with the ptex texture created in mudbox and used a file-node in Houdini to import it. I applied a pxrDisney material with the pxrptexture hooked into the base color slot. Any ideas on how to set it up correctly or what I am missing would be greatly appreciated.

cheers

Hi everyone
Is it possible to resize the voxels in a field in the middle of a DOPS simulation ?

I have a bunch of particles moving away from each other but I would like to create a field where the number of particles in each voxel stays roughly the same.

So I am looking for something similar to the “gas resize field” - node but I would like to set the voxel size at each time step based on the current state of the geometry, not just the size of the field.

Any help is greatly appreciated :wink:

Hi all. A real noob question but no luck finding an answer so far.

How do i access the different components of a matrix or vector volume in a volume wrangle or a volume VOP. I have tried using the group property in the volume wrangle and referring to the variable created. For instance @name=density.zz and then using the variable @name in the vex-snippet but to no avail. It seems straight forward. any help is greatly appreciated

Hi all

Is there a way of getting the positions of particles within a specific voxel in a volume. I know there is a solver returning the particle count in each voxel, but i would like more specific info such as the particles' native voxel as well as their position / index.

Any advice is greatly appreciated

Hi all
I was wondering if it is possible to create a voxel grid with variable voxel density. I am relatively new to houdini but i have made lots of numerical simulations before and i wanted to try that out in houdini. The goal is to simulate crack propagation but the density of voxels needed near the crack tip must be very high. This is not needed through the rest of the volume however. I have seen some simulations where the resolution of octree grids increases near boundaries. What i would need is a grid that does the same thing based on some particle attribute.

I would be able to code it in python or matlab but i'm not sure how to implement this in houdini. If anyone knows how one might approach this problem I would be very grateful

best wishes