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Found 10 results

  1. Hello all, Have been racking my brains/this forum on something seemingly quite simple, but not getting anywhere... Basically, I would like to match the scale/orientation of one set of points, based on another. Then be able to extract those 'transform' paramaters. For example, if i have a pointcloud A, with 10 points, which has been re-scalled/oriented to create Pointcloud B (in a separate process, I don't have access to those transf params). How would i then re-orient it to match? I have a photogrametry pc, which i am trying to match a tracked camera to. The issue is that the camera track is coming it at origin, so I need to transform to match the original pc. I have isolated 10 identically positioned (not identical ptnum) points from the pc & tracking data to use as 'calibrators', but can't figure out the best/most efficient next step in doing the re-orient/scale. Any help, tips, or pointers in the right direction for threads would be very much appreciated as always.
  2. EDIT : This may be something different. When parent bones have non matching scales to the current edited bone, this issue arises. Going to poke around, issue remains tho, on uniform scaled bones too. I'm not sure if this should be in the scripting forum or not... But I'm running into some issues with non-uniform scaled bone's becoming uniformly scaled when using the agent edit node. I'm specifically trying to edit the bones through vex at this point now. It seems to change a non uniform scale to a uniform scale after using the maketransform vex function. I'm noticing this issue when polar decomposition and transposing of 4x4 matricies being scaled by one of the scale's values when only modifying a position or rotation of the matrix. As tho, instead of scaling by {1.2, .8, 1.3} it scales by {1.2, 1.2, 1.2} or maybe its just the vector's length of the found eigenvalues. Like when using the agent edit node, it will change any edited bone's non-uniform scale to a uniform scale. Has anyone found a simple way to get around this, other than manually editing the matrix position W row and using dihedral math to rotate the bones?
  3. How does the pivot work when using the make transform Vop node? I am trying break down and figure out the function of the Make Transform node using python (Outside of any 3d software). The Translate is pretty basic as I can just place them into a matrix as they are x = m[3][0], y = m[3][1] and z = m[3][2]. For rotation I am using the following: def EulerToMatrix(Rotation): x, y, z = Rotation XM = M3([[ 1, 0, 0], [0, math.cos(x), -math.sin(x)], [0, math.sin(x), math.cos(x)]]) YM = M3([[math.cos(y), 0, math.sin(y)], [0, 1, 0], [-math.sin(y), 0, math.cos(y)]]) ZM = M3([[math.cos(z), -math.sin(z), 0], [math.sin(z), math.cos(z), 0], [0, 0, 1]]) return (ZM * YM * XM) I can then just pipe this information into the Matrix4. The problem I have now is that I cannot find any information that I can understand on how to apply the pivot to the matrix4. It's not as simple as just adding. I have attached a file that has the make transform that I am using to test against. The pivot seems to be linked to the rotation and so I am guessing it is related to the scale as well. Is there any way to break down how this pivot transforming works? MakeTransPiv.hip
  4. Is there a way to make the transform parameter on my subnet or HDA appear as a transform handle in the scene viewer?
  5. Hi! I'm trying to replace some non packed pieces from a bgeo sequence to a hi-res version. I cannot simulate again so I need to find a workaround to "transform input geometry" in the dop import. I've tried the 'transform pieces' sop without success. Any suggestion? Thanks! transform_pieces.hip
  6. Dynamically Modify Geometry

    I take a sphere and then apply the mountain SOP to this sphere. Then I add a Copy node which is fed a point cloud from a sphere, IsoOfset, and scatter combination. Below the Copy I place a NULL node. In this Null Node I can see the total number of packed Primitives. What I would like to do is to be able to modify the Frequency Parameter on the Mountain Sop for each of the Primitives that are being Copied so that each one of the Primitives has a unique shape. I need a variety of moon rock to blast out. Without modifying them, they all look the same. Any thoughts on how I can accomplish the ability to dynamically create rocks of various shapes. Thanks in advance.
  7. A while ago I used some very simple Matrix multiplications to bring geometry, that is positioned anywhere in space, back to the origin and from there, back to its original position. Maybe anybody here can help me remember? I think I created a world space transformation Matrix, called it myMatrix, and then multiplied it by its reverse to transform geo to the origin. In order to translate the geo back, I just multiplied by myMatrix...is that possible or am I getting something wrong? (Not in fromt of a Houdini right now) Anyway, how do I get the world space transformation matrix for an object positioned anywhere in world space, for example for some geo that came into my scene as an ABC from Maya? Lookattransform in VOPSOPs? Thanks for your hints and patience.
  8. Xform pivot

    Hi, I'm trying to learn, but I sometimes find it hard to get answers from the doc (real good doc tho). here is what I'm struggling with at the moment: I want the pivot of a transform node to to be placed relatively to another object (in the same geo node). I need the pivot to be at XMIN in x axis, 0 in y axis, ZMIN in z axis. Easy. But I need the XMIN and ZMIN of another object. Can someone help me with the syntax ? thanks !
  9. Transforms from low to high res

    Hi, Whats the workflow for simulating with low res RBD Geo and then transferring the transform information to a high res model? example https://gyazo.com/fb3e02f47fd5efe2ea3196b2d04f6206 Then taking the movement of the geo and transferring it to a much more dense/complex model Thanks guys
  10. Hi Is it possible to change camera ray_transform inside IFD using python? I can modify properties using tile script and filterCamera() function, but I can not access the transform of my camera. Thanks