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Found 6 results

1. ## split tangent and normal velocity for SDF

Hi, The picture shows an object , create > test geo > add velocity > vdbFromPolygon with vel field > visualize velocity. I wonder how to split velocity to tangent velocity and normal velocity. I guess we don't have a node to do it by one click, and need to work on volume vop/wrangle. If anyone knows how to do it, I will appreciate it, thanks!
2. ## Rendering Normal Maps?

Hey Guys! In a recent demo vid on how Houdini can be used in games, they showed how ocean fx can be used to create normal maps for fluid. at 7:46 I'm just wondering, how do I render the normal map? So far, I unwrapped my grid, and used polyframe to get my normal, tangent and bitangent. But I'm unsure on how to get the colour to reflect the correct values. From a lot of reading, it looks like I have to orient my current normal to turn it into tangent space? I've given it a guess, but it doesn't look right. My next step is then how do I bring this into COPS (what it looks like he's using) to save the normal map out? Thanks a lot! fluid_texture_02_HALP.hipnc
3. ## Tangent circle chains

I recently came across Zach's awesome work and saw this piece. Started hunting down how to achieve such an effect and found circle tangent chains is what they are called. I couldn't find out how to actually make one though? Does anyone know where I can find more info or how to do this? I was also thinking the bullet solver maybe good for this? Any ideas greatly appreciated
4. ## Rendering Motion Blur (random trails, why?)

Hello guys I need some help. I am trying to get a nice tail for the marbles in this DOP simulation. Under the Geometry node "Geometry Velocity Blur" us checked and in the Mantra node I am enabling to render Motion Blur. Is there a way to re-calculate the direction of the blur based on the particle's velocity? Cannot figure out why the direction of the blur sometimes is even perpendicular to the velocity vector! Here is the video: https://vimeo.com/112666106 Any suggestion? Thanks a lot guys!
5. ## Tangent normal maps

Hello everyone, I am trying to apply some normal maps in tangent space to some models. I used both Zbrush and xNormal for exporting the normals, none of them work. As far as I understand it, there are two types of normal maps, tangent and object space. Since the geometry will be deformed, I am using NM in tangent space. I wanted to use the default mantra surface model first, to see how it works, but it doesn't work in the first place. It basically takes in a normal map and then uses the convertNormal subnetwork (posted below). The some of the channels still seem flipped. I tried flipping other channels using the multiply node, but it simply does not work. I have tried looking it up, and there are some pretty ancient threats. One of them also provides an example file, but it seems houdini changed a bit since then. http://www.sidefx.com/exchange/info.php?fileid=561&versionid=561 The VEX function vop_computeTangents(\$tanU, \$tanV, normalize(N), \$uv, 2); does not expect the same input anymore. I haven't really worked with VEX code yet, so I am a bit stranded here. Isn't there a fast way to set tanget space normal maps up? I can't believe such a simple thing is so hard to set up. Do I need to flip certain channels when I export the NM? Am I overlooking something, or am I just really stupid? Any kind of help or information is welcome Thanks a lot Sustaxa
6. ## Normal Map for Mantra Surface Shader

I don't know why, but I've never successfully been able to import a normal map into houdini from zbrush or mudbox. I've had this issue for a year now, and I always just do bump instead. It works, but I'd rather have a tangent space normal map. Both tangent space and object space appear to screw up the lighting in Houdini renders. I'm using the mantra surface shader, default with houdini 13. Anyone know how to get this to work without the harsh edges on the shadows? Image 1 shows how the object looks with a normal map plugged in Image 2 shows how the object looks with "normal" selected from the drop down menu without the map being checked on. Image 3 shows how it looks without the normal option being selected from the drop down menu, just regular obj, no maps. Image 4 shows what I mean by "drop down menu" This is not the problem with the obj or the maps. They work fine in maya. Something weird is happening in Houdini. Thanks!!!
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