tadian
Wow, thank you. What are you inputing into the layer?
height
This is inline with other HF SOPs that expects a layer name.
And make sure to bind height to density:
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Houdini Indie and Apprentice » Sharpen Heightfield Terrains
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- animatrix_
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height
This is inline with other HF SOPs that expects a layer name.
And make sure to bind height to density:
Houdini Indie and Apprentice » Sharpen Heightfield Terrains
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- animatrix_
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Hi,
You can perform an unsharp mask in VEX on a volume like this where the second input is the output of a HeightField Blur, using a Volume Wrangle SOP:
You can perform an unsharp mask in VEX on a volume like this where the second input is the output of a HeightField Blur, using a Volume Wrangle SOP:
int index = nametoprim ( 1, chs("layer") ); float d = volumesample ( 1, index, @P ); @density += ( @density - d ) * ch("amount");
Technical Discussion » Scientific Paper Implementation in Houdini (Suggestions and Guidelines)
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- animatrix_
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That's why there is not a single skill as being able to understand any white paper. It all depends on the subject matter, algorithm and the paper at hand.
I find it best when the paper has some code or at the very least pseudocode associated with it.
I find it best when the paper has some code or at the very least pseudocode associated with it.
Houdini Learning Materials » [VEX ] How can I remap values without knowing the bounds?
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- animatrix_
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If the code is running in parallel (Run Over is not set to Detail), then you can't know the bounds until the execution finishes.
You can still get the min and max of scalar values using setdetailattrib:
https://www.sidefx.com/docs/houdini/vex/functions/setdetailattrib.html [www.sidefx.com]
But this will also require the code to finish execution.
You can still get the min and max of scalar values using setdetailattrib:
https://www.sidefx.com/docs/houdini/vex/functions/setdetailattrib.html [www.sidefx.com]
But this will also require the code to finish execution.
Houdini Indie and Apprentice » How to delete outward facing polygons, eg of a building
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- animatrix_
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Hi,
If your model is somewhat clean, you can do something like this:
Otherwise you have to do more elaborate checks using scattered points over the model and test for a single instance of an intersection or none, etc.
If your model is somewhat clean, you can do something like this:
float maxdist = ch("maxdist"); vector n = normalize ( @N ); vector p = -1; vector uvhit = 0; int primhit = intersect ( 1, @P + n * 0.1, n * maxdist, p, uvhit ); if ( primhit != -1 ) i@group_outside = 1;
Otherwise you have to do more elaborate checks using scattered points over the model and test for a single instance of an intersection or none, etc.
Houdini Lounge » How to set viewport type (top, bottom, etc) in Python
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- animatrix_
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You can do it like this:
desktop = hou.ui.curDesktop() viewport = desktop.paneTabOfType(hou.paneTabType.SceneViewer) if viewport.isCurrentTab(): view = viewport.curViewport() view.changeType(hou.geometryViewportType.Perspective)
Houdini Indie and Apprentice » How to stale along normals&
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- animatrix_
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Hi,
You can use the Peak SOP. But if you don't want vertical scaling, you can use this VEX code in a Point Wrangle SOP:
You can use the Peak SOP. But if you don't want vertical scaling, you can use this VEX code in a Point Wrangle SOP:
vector n = @N; n.y = 0; @P += n * ch("scale");
Technical Discussion » (Un)evenly distributed subdivision
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- animatrix_
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Technical Discussion » reconstruct subdivisions like in Zbrush?
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- animatrix_
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There is a paper on this that you can implement:
https://www.researchgate.net/publication/228968237_Reverse_Catmull-Clark_Subdivision [www.researchgate.net]
https://www.researchgate.net/publication/228968237_Reverse_Catmull-Clark_Subdivision [www.researchgate.net]
Technical Discussion » How to create unevenly distributed points along a curve?
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- animatrix_
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You can do this easily with primuvconvert and primuv VEX functions. Just move the reference curve points over the curve you want to resample after you compute unit length U coordinates.
float n = float ( @ptnum ) / ( len ( primpoints ( 0, @primnum ) ) - 1 ); float u = primuvconvert ( 0, n, @primnum, 4 ); @P = primuv ( 1, "P", 0, u );
Technical Discussion » Can you rig a vehicle in Houdini?
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- animatrix_
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Digipiction
I've looked at your scene and couldn't find any relevant differences to my own scene, except for the orient attribute. And sure enough, that attribute appears to be massively important, even though you're just giving it the default value it seems.
How did you know that this is needed? It's not mentioned at all in the documentation for condir and condof.
Here's your scene slightly modified: I turned the collision shape into a regular ground plane, I added a POP force pushing the car body along X, and I deactivated the orient initialization. The result is what I'd been fighting with for days, i.e. the wheels doing weird things, ignoring their constraint directions. But if you re-enable the orient initialize, it works as expected.
So thanks of course, this is great to know! I have a feeling I'm now among roughly 12 people in the world who have this insight. Having to add 3 barely doccumented attributes via wrangles just to make directional constraints work is harsh even by Houdini's standards.
They are documented here:
https://www.sidefx.com/docs/houdini/nodes/dop/constraintnetwork.html [www.sidefx.com]
Technical Discussion » vex problem with initializing a funtion
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- animatrix_
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Many problems in that code.
1. You have to use ; between arguments with type or just comma without typing the type name for same type arguments:
or
2. No createDialog function.
3. Invalid foreach loop:
There might be more after you fix #2.
1. You have to use ; between arguments with type or just comma without typing the type name for same type arguments:
float infectionSolver(float infection; float timeStep; float diffusion; float decay; int maxIterations)
or
float infectionSolver(float infection, timeStep, diffusion, decay; int maxIterations)
2. No createDialog function.
3. Invalid foreach loop:
for(int pt = 0; pt < npoints(0); ++pt )
There might be more after you fix #2.
Technical Discussion » Move points to their closest unique neighbors
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- animatrix_
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Hi,
There are many ways to do this, including proper VEX methods that are a bit more involved. But for this case you can use a simple solution:
1. Flatten the first point cloud in Y temporarily (rest attribute).
2. Sort the points of both point clouds by proximity to origin (0, 0, 0).
3. Revert the original point positions of the first point cloud.
4. Now you can use Blendshape SOP.
There are many ways to do this, including proper VEX methods that are a bit more involved. But for this case you can use a simple solution:
1. Flatten the first point cloud in Y temporarily (rest attribute).
2. Sort the points of both point clouds by proximity to origin (0, 0, 0).
3. Revert the original point positions of the first point cloud.
4. Now you can use Blendshape SOP.
Houdini Lounge » Alpha "erode" texture for stylized FX in houdini
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- animatrix_
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Hi,
You can implement it as a volume operation using volume convolution:
The above convolution kernel dilates the voxels so you take the difference between this and the original volume, then subtract this from the original volume. You can also volume blur the difference volume before subtraction if you want smoother result.
If you want max performance, consider implementing it in OpenCL which could reach/surpass real-time speeds depending on your GPU.
You can implement it as a volume operation using volume convolution:
The above convolution kernel dilates the voxels so you take the difference between this and the original volume, then subtract this from the original volume. You can also volume blur the difference volume before subtraction if you want smoother result.
If you want max performance, consider implementing it in OpenCL which could reach/surpass real-time speeds depending on your GPU.
Technical Discussion » How to group sharp turned points on edges?
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- animatrix_
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Hi,
You can use compare tangent angles like this:
You can use compare tangent angles like this:
int pts [ ] = primpoints ( 0, @primnum ); int index = find ( pts, @ptnum ); int pt = pts [ index + 1 ]; vector tangent = point ( 0, "tangent", pt ); if ( dot ( v@tangent, tangent ) < ch("angle" ) ) i@group_pts = 1;
Technical Discussion » Visualizing Mesh Thickness
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- animatrix_
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Hi,
You can do an approximation using the Mask by Ambient Occlusion SOP. You have to edit the code to shoot the rays from the inside of the geometry by the inverted normal direction (Line 106):
The resolution of the mesh matters so you can add additional detail using the Divide SOP.
You can do an approximation using the Mask by Ambient Occlusion SOP. You have to edit the code to shoot the rays from the inside of the geometry by the inverted normal direction (Line 106):
ao = vop_bias(raytest(v@P - aorayoffset * nml, -nml, aomaxraydist, aosamples, aoseed, pt_id, aoconeangle), aobias);
The resolution of the mesh matters so you can add additional detail using the Divide SOP.
Houdini Indie and Apprentice » Simulating hopper crystal growth
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- animatrix_
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Houdini Indie and Apprentice » Projecting correctly onto this target surface?
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- animatrix_
- 3810 posts
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Hi,
You can easily do this by attrib transfering normals from the large surface to the small surface, blur normals optionally, and then use Ray SOP after with the Normal option and then delete N.
You can easily do this by attrib transfering normals from the large surface to the small surface, blur normals optionally, and then use Ray SOP after with the Normal option and then delete N.
Houdini Learning Materials » Pragmatic VEX: Volume 1 [4K] [H19.5]
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- animatrix_
- 3810 posts
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__feisar__
Congratz, well deserved.
The amount of content in volume 1 is mind blowing. It is the gold standard for houdini training. Zero fluff, clear explanations followed by the implementation.
Will Volume 2 come this year?
Thanks a lot, appreciate it!
Volume 2 will be out this year! Hopefully Q2, if not Q3 as this volume is longer than volume 1 so it takes more time.
Houdini Learning Materials » Pragmatic VEX: Volume 1 [4K] [H19.5]
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- animatrix_
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Google is the latest company to join again the impressive list of companies and studios that use Pragmatic VEX: Volume 1 as part of their training. It shows how some companies truly value the growth of their employees, which makes it an even better place to work at!
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