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Houdini Indie and Apprentice » Creating POPs with unique source geometry
- david_aiken
- 86 posts
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Thanks. I looked about in the docs/tutorials before posting and didn't find a mention but it seems reasonable. I'll look at another way to do this….
Houdini Indie and Apprentice » Creating POPs with unique source geometry
- david_aiken
- 86 posts
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I'm trying to create a large number of POP networks, each using unique source geometry. I gave it a try using the ForEach SOP to create sweep geometry using a passed-in curve and use this geometry as a POP source. In my experiment (attached) only the particles at grid point 0 flow freely. The particles at 99 also flow a bit. All of the other POPs are generating particles but after a brief surge on frame 1 they stop.
I simplified it by just creating a POP in the ForEach, but the source at grid point 0 didn't generate particles.
I'm using Houdini 11.0.504 on 64-bit Ubuntu 10.04.
I'll submit a bug if someone can reproduce it.
If there is a workaround or a different approach please let me know.
I simplified it by just creating a POP in the ForEach, but the source at grid point 0 didn't generate particles.
I'm using Houdini 11.0.504 on 64-bit Ubuntu 10.04.
I'll submit a bug if someone can reproduce it.
If there is a workaround or a different approach please let me know.
Houdini Indie and Apprentice » Dust Effect
- david_aiken
- 86 posts
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The fxphd HOU 101 course features dust kicked up by dragon wings hitting the ground. Perhaps your director might consider introducing a dragon 8). This is great for larger effects, but footfalls take up less screen. District 9 did dust impact from footfalls in comp.
Houdini Indie and Apprentice » ptex sampling
- david_aiken
- 86 posts
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hi all..
I'm mapping a texture map to a sphere represented as a polygon quad mesh. If i do a UV Project using polar project and vertices it's fine. When i switch the projection to points a seam appears. I'm using texni() farther down the pipe to sample the texture for a given point so the seam is a problem. I could brute-force it by calculating the uv coordinates myself, but maybe someone knows a better way.
Of course this may be moot. Is it possible/reasonable to use ptex to avoid seams altogether? I've been poking around and got a simple demo running, but actually taking a 2D texture, projecting it onto a sphere, then exporting it as a ptex, and sampling it in VEX or via something like texni() in an expression seems like Work currently. Does anyone have experience with something like this? Just curious at this point i think.. seems like 3D Coat might be able to do it.
thanks!
I'm mapping a texture map to a sphere represented as a polygon quad mesh. If i do a UV Project using polar project and vertices it's fine. When i switch the projection to points a seam appears. I'm using texni() farther down the pipe to sample the texture for a given point so the seam is a problem. I could brute-force it by calculating the uv coordinates myself, but maybe someone knows a better way.
Of course this may be moot. Is it possible/reasonable to use ptex to avoid seams altogether? I've been poking around and got a simple demo running, but actually taking a 2D texture, projecting it onto a sphere, then exporting it as a ptex, and sampling it in VEX or via something like texni() in an expression seems like Work currently. Does anyone have experience with something like this? Just curious at this point i think.. seems like 3D Coat might be able to do it.
thanks!
Houdini Indie and Apprentice » Deep Camera Map compositing
- david_aiken
- 86 posts
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hi all..
Is there a recommended workflow for Deep Camera Maps? I was hoping to combine them in arbitrary combinations in COPS since they are volumetric (Seurat 3D!), but the DSM Flatten COP wants to work on a single DCM file rather than multiple files at once so overlap relationships are lost. The DSM Merge ROP will handle multiple DCMs, but it wants to do so at render time so i think it loses some flexibility.
Is there a way to work with multiple DCMs at comp time? It seems like it would be useful since Nuke users have many passes (with many names :shock: ) incorporating depth/colour/primitive geometry information.
thanks!
Is there a recommended workflow for Deep Camera Maps? I was hoping to combine them in arbitrary combinations in COPS since they are volumetric (Seurat 3D!), but the DSM Flatten COP wants to work on a single DCM file rather than multiple files at once so overlap relationships are lost. The DSM Merge ROP will handle multiple DCMs, but it wants to do so at render time so i think it loses some flexibility.
Is there a way to work with multiple DCMs at comp time? It seems like it would be useful since Nuke users have many passes (with many names :shock: ) incorporating depth/colour/primitive geometry information.
thanks!
Houdini Indie and Apprentice » VEX behavior
- david_aiken
- 86 posts
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Houdini Indie and Apprentice » VEX behavior
- david_aiken
- 86 posts
- Offline
hi all..
This VEX code stashes the point number in a string point attribute using Houdini 11.0.504:
sop
vexeg(
string pcloud_texture = “op:`opinputpath('.',0)`”;
float maxdist = 100.0;
int maxpnts = 10;
)
{
int src_number = ptnum;
int handle = pcopen(pcloud_texture, “P”, P, maxdist, (int)maxpnts);
string tst_str = “”;
while (pciterate(handle) )
{
tst_str = tst_str + sprintf(“%d;”, src_number);
}
addattribute(“tst”, tst_str);
}
The resulting “tst” attribute value is as follows:
Node tst
0 0;0;0;0;0;0;0;0;0;0;
1 0;1;1;1;1;1;1;1;1;1;1;
2 0;2;2;2;2;2;2;2;2;2;2;
So somehow i'm getting an extra entry after point 0. The compile reports success. Is there something wrong with the code? It seems tst_str is not getting initialised to “” for each node.
thanks!
This VEX code stashes the point number in a string point attribute using Houdini 11.0.504:
sop
vexeg(
string pcloud_texture = “op:`opinputpath('.',0)`”;
float maxdist = 100.0;
int maxpnts = 10;
)
{
int src_number = ptnum;
int handle = pcopen(pcloud_texture, “P”, P, maxdist, (int)maxpnts);
string tst_str = “”;
while (pciterate(handle) )
{
tst_str = tst_str + sprintf(“%d;”, src_number);
}
addattribute(“tst”, tst_str);
}
The resulting “tst” attribute value is as follows:
Node tst
0 0;0;0;0;0;0;0;0;0;0;
1 0;1;1;1;1;1;1;1;1;1;1;
2 0;2;2;2;2;2;2;2;2;2;2;
So somehow i'm getting an extra entry after point 0. The compile reports success. Is there something wrong with the code? It seems tst_str is not getting initialised to “” for each node.
thanks!
Houdini Indie and Apprentice » VEX SOP shared variable
- david_aiken
- 86 posts
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hi all..
This may be a FAQ.. not sure. I'm iterating through a point cloud in a VEX SOP and would like to keep a counter variable for each point which contains the number of times that point has been modified.
I've tried doing this by creating a point attribute upstream in the SOP chain via AttribCreate then using a pcimport() to read it followed by an increment and a pcexport() but it states that a “read-only channel has been passed to pcexport()” and the attribute isn't updated (Attached).
I've got several alternatives, but if anyone knows a good approach it would be appreciated.
thanks!
This may be a FAQ.. not sure. I'm iterating through a point cloud in a VEX SOP and would like to keep a counter variable for each point which contains the number of times that point has been modified.
I've tried doing this by creating a point attribute upstream in the SOP chain via AttribCreate then using a pcimport() to read it followed by an increment and a pcexport() but it states that a “read-only channel has been passed to pcexport()” and the attribute isn't updated (Attached).
I've got several alternatives, but if anyone knows a good approach it would be appreciated.
thanks!
Houdini Indie and Apprentice » .rat texture read examples
- david_aiken
- 86 posts
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FYI there is a lot of helpful info in the HDK docs - “Getting Data In And Out Of Houdini”.. i missed it in my initial google search .
Houdini Indie and Apprentice » custom ROP integration with flipbook
- david_aiken
- 86 posts
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Thanks Mark.. i think that is what i was looking for.
Rafaels - some people find ip useful for convenient, quick, iterative preview to polish up the image - typically at lower resolution. The intent isn't usually to watch each tile as it renders. For final render it often goes out to a farm.
Rafaels - some people find ip useful for convenient, quick, iterative preview to polish up the image - typically at lower resolution. The intent isn't usually to watch each tile as it renders. For final render it often goes out to a farm.
Houdini Indie and Apprentice » custom ROP integration with flipbook
- david_aiken
- 86 posts
- Offline
hi all..
Probably not a FAQ, but if a custom ROP outputs an image file how can it get the flipbook and/or Render View to display the image during the render?
thanks!
Probably not a FAQ, but if a custom ROP outputs an image file how can it get the flipbook and/or Render View to display the image during the render?
thanks!
Houdini Indie and Apprentice » EXR channels in COPS
- david_aiken
- 86 posts
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Houdini Indie and Apprentice » .rat texture read examples
- david_aiken
- 86 posts
- Offline
hi all..
I would like to be able to determine the RGB value at a particular pixel within a .rat file (this particular one, according to MPlay, is RGB 8-bit integer, no interlacing, single plane, 2D raster). It looks like the HDK classes IMG_File and PXL_Raster may be suitable. If so, are any examples available?
thanks!
I would like to be able to determine the RGB value at a particular pixel within a .rat file (this particular one, according to MPlay, is RGB 8-bit integer, no interlacing, single plane, 2D raster). It looks like the HDK classes IMG_File and PXL_Raster may be suitable. If so, are any examples available?
thanks!
Houdini Indie and Apprentice » EXR channels in COPS
- david_aiken
- 86 posts
- Offline
hi all..
Does anyone know if it is possible to do multi-pass with specific (non-standard) EXR channels within COPS?
I can load up an EXR image in the File node, but “There are no input options defined for the OpenEXR format” appears in the dialog. Not a problem as I can always render separate EXRs or jump to Nuke.
thanks!
Does anyone know if it is possible to do multi-pass with specific (non-standard) EXR channels within COPS?
I can load up an EXR image in the File node, but “There are no input options defined for the OpenEXR format” appears in the dialog. Not a problem as I can always render separate EXRs or jump to Nuke.
thanks!
Houdini Indie and Apprentice » VRAY_Procedural args
- david_aiken
- 86 posts
- Offline
Houdini Indie and Apprentice » VRAY_Procedural args
- david_aiken
- 86 posts
- Offline
In fact, i'm having difficulty running the VRAY_DemoBox sample. I've run hcustom and the .so is in $HFS/houdini/dso and the VRAYprocedural in $HFS/houdini has a reference to it. When i start houdini it complains:
/opt/hfs11.0.446.9/houdini/dso/VRAY_DemoBox.so: undefined symbol: _ZTI15VRAY_Procedural
If i run an nm across the .so files under $HFS i find a weak reference to it in libHoudiniRAY.so, but nothing seems to provide it. Is it available in Houdini 11 Apprentice?
/opt/hfs11.0.446.9/houdini/dso/VRAY_DemoBox.so: undefined symbol: _ZTI15VRAY_Procedural
If i run an nm across the .so files under $HFS i find a weak reference to it in libHoudiniRAY.so, but nothing seems to provide it. Is it available in Houdini 11 Apprentice?
Houdini Indie and Apprentice » VRAY_Procedural args
- david_aiken
- 86 posts
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hi all..
Just curious.. is it possible to pass parameters to a VRAY_Procedural in Apprentice?
thanks!
Just curious.. is it possible to pass parameters to a VRAY_Procedural in Apprentice?
thanks!
Houdini Indie and Apprentice » ROP output driver
- david_aiken
- 86 posts
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Houdini Indie and Apprentice » ROP output driver
- david_aiken
- 86 posts
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It's fairly straightforward to create a standard SOP that outputs a file, so it's not blocking me. The SOHO docs mention image file extensions, but geometry doesn't seem to be covered.. maybe i've missed something.
Houdini Indie and Apprentice » ROP output driver
- david_aiken
- 86 posts
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hi all..
Is there a way to create a custom node like the “ROP Output Driver” SOP using the HDK, or perhaps extend it to support a custom file format?
thanks
Is there a way to create a custom node like the “ROP Output Driver” SOP using the HDK, or perhaps extend it to support a custom file format?
thanks
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