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Houdini Indie and Apprentice » Procedural Text Animation
- cspears2002
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Houdini Indie and Apprentice » Procedural Text Animation
- cspears2002
- 38 posts
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Hi!
I am working my way through the Procedural Text Animation tutorial. I keep getting this error in one of my Point SOPs:
Error: Channel evaluation error Undefined variable (/obj/FirstIPop/point_modify_prs/val1i1).
The error seems to be generated from my attempts to randomize a custom scale attribute with an expression like so:
$SCALE1 * fit01(rand($PT * 234),0.7,1.5)
What is confusing to me is that I copied the expression exactly from the tutorial! What am I doing wrong? I've included the hip with this posting.
I am working my way through the Procedural Text Animation tutorial. I keep getting this error in one of my Point SOPs:
Error: Channel evaluation error Undefined variable (/obj/FirstIPop/point_modify_prs/val1i1).
The error seems to be generated from my attempts to randomize a custom scale attribute with an expression like so:
$SCALE1 * fit01(rand($PT * 234),0.7,1.5)
What is confusing to me is that I copied the expression exactly from the tutorial! What am I doing wrong? I've included the hip with this posting.
Houdini Indie and Apprentice » no license for Mantra
- cspears2002
- 38 posts
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Hi!
I've been working on the stickies tutorial with Houdini Apprentice 11.0.775. However when I right click the reel icon and select ‘View:Mantra’, I get the following error message:
No licenses could be found to run this application.
Please check for a valid license server host
Should Houdini Apprentice come with Mantra license? Any help would be appreciated!
Thanks!
I've been working on the stickies tutorial with Houdini Apprentice 11.0.775. However when I right click the reel icon and select ‘View:Mantra’, I get the following error message:
No licenses could be found to run this application.
Please check for a valid license server host
Should Houdini Apprentice come with Mantra license? Any help would be appreciated!
Thanks!
Houdini Indie and Apprentice » puff of smoke in a box
- cspears2002
- 38 posts
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Hi,
I am trying to create a puff of smoke from an animated box, which is a passive RBD object. Unfortunately, the smoke penetrates the box no matter what I do. I made the box thicker. I increased the divisions on the Collision Geometry. I played with the Sub Steps on the RBD solver, the Pyro Solver, and the AutoDopNetwork. All to no effect! Any hints? I attached the scene file to this post.
I am trying to create a puff of smoke from an animated box, which is a passive RBD object. Unfortunately, the smoke penetrates the box no matter what I do. I made the box thicker. I increased the divisions on the Collision Geometry. I played with the Sub Steps on the RBD solver, the Pyro Solver, and the AutoDopNetwork. All to no effect! Any hints? I attached the scene file to this post.
Houdini Indie and Apprentice » keeping reflections in a comp
- cspears2002
- 38 posts
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I'm trying to composite an image into a photo of a television set. I managed to place the image correctly. However, I lost all of the great reflections, etc. from the original plate.
In my scene file, I managed to matte out the screen without the image, but I'm not sure how to combine it with my comp. I have been trying to create an alpha matte with a ramp, but, so far, I have been unsuccessful.
In my scene file, I managed to matte out the screen without the image, but I'm not sure how to combine it with my comp. I have been trying to create an alpha matte with a ramp, but, so far, I have been unsuccessful.
Work in Progress » monitor comp
- cspears2002
- 38 posts
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Ok I renderd out my element at 720x405 and comped it into the photo and added more blur and grain. Looking pretty good. However, I think I see some jaggies on the right side of the monitor.
Work in Progress » monitor comp
- cspears2002
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I rendered the image with a 16:9 aspect ration. Since I am using Apprentice, I am limited to 720x576. The resulting image looks squished. Should I stretch out the image before compositing? I tried doubling 720 to 1440, but the resulting image looked stretched.
Houdini Indie and Apprentice » shading multiple objects with one shader
- cspears2002
- 38 posts
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I'm working through the “Writing a VEX Shader for Houdini” tutorial written by Andy Nicholas. In the tutorial, he demonstrates how to drive a shader with an attribute. I created a geo node at the object level, jumped in, and created several spheres. I used an attribute called “wrap” to drive the shader and assigned a different value to this attribute for each sphere.
The spheres were then merged. When I rendered the spheres, they looked the same! However, when I render each sphere separately, they look different, which is the effect I was going for.
One solution to this conundrum is to create separate spheres at the object level. However, I was wondering if I can achieve the effect I want at the geometry level.
The spheres were then merged. When I rendered the spheres, they looked the same! However, when I render each sphere separately, they look different, which is the effect I was going for.
One solution to this conundrum is to create separate spheres at the object level. However, I was wondering if I can achieve the effect I want at the geometry level.
Work in Progress » monitor comp
- cspears2002
- 38 posts
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I double checked the comp, and the rendered image is not distorted. I removed some of the blue and added a touch of grain.
Work in Progress » monitor comp
- cspears2002
- 38 posts
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Are you asking if the rendered image is stretched? Not sure. The corner pin may be distorting it somewhat. I should check that with a checkerboard texture.
Work in Progress » monitor comp
- cspears2002
- 38 posts
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I composited a scene I rendered out in Houdini in to a photo I took of my television. Let me know what you think!
Work in Progress » no attachments?
- cspears2002
- 38 posts
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Work in Progress » microworld
- cspears2002
- 38 posts
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Here is my final render for my electron microscope scene. I might try to comp it into a monitor next. Let me know what you think!
Work in Progress » no attachments?
- cspears2002
- 38 posts
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Hi,
I would like to post some images and scene files from a personal project I have been working on in Houdini Apprentice to the Work In Progress forum. Unfortunately, I cannot do this because the interface that allows me to add attachments does not show up when I log in to this forum. Am I doing something wrong?
Thanks.
I would like to post some images and scene files from a personal project I have been working on in Houdini Apprentice to the Work In Progress forum. Unfortunately, I cannot do this because the interface that allows me to add attachments does not show up when I log in to this forum. Am I doing something wrong?
Thanks.
Houdini Indie and Apprentice » learning vex
- cspears2002
- 38 posts
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After rolling my own shader with VOPS, I have become interested in learning vex. What's the best way to start? Are there any good tutorials or books out there?
Houdini Indie and Apprentice » improved electron microscope shader
- cspears2002
- 38 posts
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I'm getting closer to nailing down my electron microscope scene. I took some advice from Jeff on constructing the shader. The quote is included below. My solution was to create a headlamp shader that the user can invert with a parameter. The surface color is created by combining the headlamp shader with a lambert shader. Finally, I use COPs to tweak the look. Let me know what you think!
I want to tackle depth of field next. Which method is best? Should I use the depth of field effect available in mantra or the one in COPs?
I want to tackle depth of field next. Which method is best? Should I use the depth of field effect available in mantra or the one in COPs?
Just to be geekey…
Few care to realize that an electron microscope image is a “false image”. Some objects observe what looks like lambertian headlight shading while others exhibit the inverse of that lighting model.
Take a look at the poster boy image of pollen in the wikipedia web site:
http://en.wikipedia.org/wiki/File:Misc_pollen.jpg [en.wikipedia.org]
You'll notice that the smaller pollen in between the larger pollen have bright edges and dark centers. Reverse of default Lambertian shading. No they are not the shape of blood cells but are roughly spherical.
Here's another image where the entire critter is shown in this reverse lambertian like headlight lighting model:
http://farm1.static.flickr.com/232/535424122_ad2369aa79.jpg [farm1.static.flickr.com]
No there are no “lights” in an electron microscope so rim lighting makes no sense to solve this problem.
If you research this further (which all prospective shader writers should do ) you will find that smaller thinner structures will exhibit this reverse-lambertian shading while larger solid objects shade with a lambertian response. Then there is the electron microscope itself. Depending on the model it varies as well. All depends on how the structures were coated with a metal (usually gold as it can be put in an incredibly thin layer) and how the electron microscope renders the collected bounced electrons' energy.
You will want a control on your electron microscope shader that allows you to flip the shading on a per structure basis if you really want to leapfrog the endless supply of physically incorrect electron microscope shaders that seem to proliferate the web-o-sphere…
Houdini Indie and Apprentice » selecting primitives with geometry
- cspears2002
- 38 posts
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I'm trying to surround the object called diatom in the center of the scene with a ring of debris. My original plan was to use a torus or similar piece of geometry to select the primitives surrounding the diatom and group them. Then I would scatter points over that group and copy platonic objects to them.
Unfortunately, you can only use geometry to create a point group. I tried to convert a point group to a primitive group, but I was unable to.
Any suggestions?
Unfortunately, you can only use geometry to create a point group. I tried to convert a point group to a primitive group, but I was unable to.
Any suggestions?
Houdini Indie and Apprentice » electron microscope look -- for cspears2002
- cspears2002
- 38 posts
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Thanks! I downloaded the file. Unfortunately, the latest version of Apprentice that I can download is still 10.0.295. Hopefully, a newer version will be available shortly!
Work in Progress » electron microscope look
- cspears2002
- 38 posts
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I keep getting a Memory Allocation Error. I am running Houdini Apprentice 10.0.295 on Dell laptop running 32 bit Windows Vista. Granted my choice of OS is probably not the greatest, but I was wondering if there was something I could do in my scene file to improve things.
Work in Progress » electron microscope look
- cspears2002
- 38 posts
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Here are two new versions. microworld_area_comp.jpg was rendered with an area light. I did NOT adjust te brightness/contrast.
The other image is called microworld_comp.jpg and was rendered with ambient occlusion. I did adjust the brightness/contrast in COPs.
Currently leaning towards microworld_area_comp.jpg for aesthetic reasons and because it doesn't cause my laptop to crash all the time. What do you think?
The other image is called microworld_comp.jpg and was rendered with ambient occlusion. I did adjust the brightness/contrast in COPs.
Currently leaning towards microworld_area_comp.jpg for aesthetic reasons and because it doesn't cause my laptop to crash all the time. What do you think?
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