i do not know much about .rat files
but according to this http://odforce.net/wiki/index.php/Rat [odforce.net]
each texture is converted to rat before rendering
so with converting it yourself you gain some speed increment in render startup and more efficient memory management since only needed parts of the image will be loaded from disk
so this all means that you can use hdr images and it should produce the same render as rat file converted from them.
if you decide for .rat
you can convert the whole sequence to .rat in COPs or MPlay
Found 5518 posts.
Search results Show results as topic list.
Houdini Indie and Apprentice » Environments, refl/refract and alphas
- tamte
- 8595 posts
- Offline
Houdini Indie and Apprentice » Environments, refl/refract and alphas
- tamte
- 8595 posts
- Offline
luckymutt
…
Creating a plane, aligned it to the camera, pushed it back and parented it to the camera.
I added a UV Texture SOP and set it to Prespective From Camera, and I applied a Constant shader with my background footage.
Works well enough.
However, having to go through setting this up seems less than ideal
…
you can allways make an digital asset from this setup
and use it every time you need it
Some time ago i've built similar asset which was creating grid with exact dimensions just by specifying Camera, Distance and Texture Map. There was some math involved to get the right dimensions according to FOV, aspect, distance … but nothing too difficult.
Your approach with camera projection seems quite interesting and simplier.
It may have some downsides however.
1. the projected texture can be distorted if you are using UVtexture SOP to create camera uvs.
But you can extract per pixel camera coordinates directly in the shader and use them instead for your texture to solve this
2. if you create large sphere around the scene and project your image just from the camera view. It will look right from the camera, but i am not sure what image information will be on the rest surface of the sphere and thus what will be visible in the reflections/refractions. So it may require some customisation of the shader to for example set the opacity to 0 for all the surface off the camera.
but back to your question:
the enviroBox will not work with the custom UV mapping you are doing in SOPs because it is using environment VOP for the color (i can be wrong though)
constant material should work
just make sure your bg geometry e.g. large sphere sphere is not primitive type, because UVtexture SOP is creating information on points and since primitives are only 1 point UVs will not be correct
and if you are using polygonal sphere make sure you have enough subdivisions to reduce distortion
Technical Discussion » VOP cannot use CHOP
- tamte
- 8595 posts
- Offline
according to your screencap, i can see that you have created the Parameter VOP, but notice that the parameter you are trying to animate is called “1 float default” which literally means that value specified there is used as the default value of the parameter when the VOP network is compiled. The actual parameter you want to animate is located one level above on the VOP network itself.
At this level you can animate it and use expressions
(i am not sure if your question was also about expressions then this might help you anyways)
you can use “if” expression to specify conditions
like if($F>100 && $F<200, $F*0.1, 0) or more complex
also notice in graph editor that you can select curve segment between 2 keyframes
then you can specify function of that segment like linear(), bezier()…
but besides those you can write there any expression you want and it will be used only for that segment
you can use there channel variables from http://www.sidefx.com/docs/houdini10.0/expressions/_globals [sidefx.com]
to have full control
At this level you can animate it and use expressions
(i am not sure if your question was also about expressions then this might help you anyways)
you can use “if” expression to specify conditions
like if($F>100 && $F<200, $F*0.1, 0) or more complex
also notice in graph editor that you can select curve segment between 2 keyframes
then you can specify function of that segment like linear(), bezier()…
but besides those you can write there any expression you want and it will be used only for that segment
you can use there channel variables from http://www.sidefx.com/docs/houdini10.0/expressions/_globals [sidefx.com]
to have full control
Houdini Indie and Apprentice » SOP vector field node
- tamte
- 8595 posts
- Offline
the scalar field example is about masking gravity by scalar field
which make no sense for the glued object since all glued RBDs are threated as one object and they will not separate this way
therefore i posted info about ChoreographedBreakup Example since krizard mentioned he wants to use RBD Glue obj
which make no sense for the glued object since all glued RBDs are threated as one object and they will not separate this way
therefore i posted info about ChoreographedBreakup Example since krizard mentioned he wants to use RBD Glue obj
Technical Discussion » VOP cannot use CHOP
- tamte
- 8595 posts
- Offline
you cannot animate vops directly, because they are being compiled to the vex code
what you need to do is create a parameter VOP and connect it to bias input (or middle click on bias input and choose Create Parameter Node)
the Parameter VOP will be promoted to the shader parameters and you can animate it there
what you need to do is create a parameter VOP and connect it to bias input (or middle click on bias input and choose Create Parameter Node)
the Parameter VOP will be promoted to the shader parameters and you can animate it there
Houdini Indie and Apprentice » instancepoint() question
- tamte
- 8595 posts
- Offline
use it on object which you are instancing
or its material
it will give you point number which the object is instanced onto
if you need the color then, you will need to use point() expression to get the point color from the instance points based on instancepoint()
you can also use it in material overrides as in attached file
or its material
it will give you point number which the object is instanced onto
if you need the color then, you will need to use point() expression to get the point color from the instance points based on instancepoint()
you can also use it in material overrides as in attached file
Houdini Indie and Apprentice » SOP vector field node
- tamte
- 8595 posts
- Offline
edit: deleted
this was kind of doublepost because of some problems in the forum and missing posts
this was kind of doublepost because of some problems in the forum and missing posts
Houdini Indie and Apprentice » Environments, refl/refract and alphas
- tamte
- 8595 posts
- Offline
i am usually using big sphere around the scene with constant shader, either with rat or hdri map, it can be sequence of course
the sphere is set as phantom so it is visible only for secondary rays
the sphere is set as phantom so it is visible only for secondary rays
Houdini Indie and Apprentice » SOP vector field node
- tamte
- 8595 posts
- Offline
then i suggest you to look at ChoreographedBreakup Example from help examples.
the technique used there can be used with active value or other (per object) parameters. But for your needs that example should be what you want
the technique used there can be used with active value or other (per object) parameters. But for your needs that example should be what you want
Technical Discussion » With force,how to make particle move uniform circularly?
- tamte
- 8595 posts
- Offline
The initial force you applied is 4 in global X direction
then you are just adding incentric force, i cannot see the reason why it should be circular this way
Try using Orbit POP, it is made for this kind of motion
or you can make your own force with VOP POP
then you are just adding incentric force, i cannot see the reason why it should be circular this way
Try using Orbit POP, it is made for this kind of motion
or you can make your own force with VOP POP
Houdini Indie and Apprentice » SOP vector field node
- tamte
- 8595 posts
- Offline
you do not need sop vector field as a mask, Sop scalar field is ok. You do not have 3 volume primitives in your geometry anyways
but to your problem
see first attached file
for simplier solution you can animate activness of the second box by adding Active Value DOP and animating active parameter
see second file
but to your problem
see first attached file
for simplier solution you can animate activness of the second box by adding Active Value DOP and animating active parameter
see second file
Technical Discussion » wire constraint weight
- tamte
- 8595 posts
- Offline
Technical Discussion » MAKING wire / chain ?
- tamte
- 8595 posts
- Offline
here are some links that can be helpful
http://www.sidefx.com/index.php?option=com_content&task=view&id=1242&Itemid=132 [sidefx.com]
http://www.sidefx.com/index.php?option=com_content&task=view&id=1399&Itemid=132 [sidefx.com]
http://www.sidefx.com/index.php?option=com_content&task=view&id=1400&Itemid=132 [sidefx.com]
http://www.sidefx.com/index.php?option=com_content&task=view&id=1242&Itemid=132 [sidefx.com]
http://www.sidefx.com/index.php?option=com_content&task=view&id=1399&Itemid=132 [sidefx.com]
http://www.sidefx.com/index.php?option=com_content&task=view&id=1400&Itemid=132 [sidefx.com]
Technical Discussion » MAKING wire / chain ?
- tamte
- 8595 posts
- Offline
the base tool for both is Curve SOP or you can work with any curve in houdini
then to make wire from it you can either sweep circle along it and skin it or use PolyWire SOP or Wireframe SOP
for chain you will probably need Resample SOP and Copy SOP
see attached file as an example
then to make wire from it you can either sweep circle along it and skin it or use PolyWire SOP or Wireframe SOP
for chain you will probably need Resample SOP and Copy SOP
see attached file as an example
Technical Discussion » How to mask vector field by scalar field?
- tamte
- 8595 posts
- Offline
I've found Gas Field VOP, it is working now
but i am still curious if it is possible with Gas Calculate
but i am still curious if it is possible with Gas Calculate
Houdini Lounge » EDIT SOP
- tamte
- 8595 posts
- Offline
Technical Discussion » how to use geometry as a light source ?
- tamte
- 8595 posts
- Offline
i think it is possible with light instancing
either on geo points or scatter new points on surface and instance lights on them
i am not sure about speed however, it can be really slow with many lights, or?
either on geo points or scatter new points on surface and instance lights on them
i am not sure about speed however, it can be really slow with many lights, or?
Technical Discussion » How to mask vector field by scalar field?
- tamte
- 8595 posts
- Offline
Hi, I am doing smoke simulation with one custom vector field Cd to colorize my smoke and I want to mask it by density field
i have tried Gas Calculate with Cd as dest field and density as source, calculation method set to Multiply but it is obviously not working. Maybe because Cd is vector and density is scalar (because the same setup works when i use vel as source, but of course with wrong results)
is there any way to make it work?
i have tried Gas Calculate with Cd as dest field and density as source, calculation method set to Multiply but it is obviously not working. Maybe because Cd is vector and density is scalar (because the same setup works when i use vel as source, but of course with wrong results)
is there any way to make it work?
Houdini Indie and Apprentice » Particle point instance attribute control
- tamte
- 8595 posts
- Offline
you still have control over displacement per instance
so if you can do your geometry modification through displacement shader, you can use instances
so if you can do your geometry modification through displacement shader, you can use instances
Houdini Indie and Apprentice » Particle point instance attribute control
- tamte
- 8595 posts
- Offline
since you are after geometric change on each instance, it would not be true instance anymore, because mantra has to keep all modified geometry in memory
you can append copy sop after the pop network for that kind of thing
read this for more info
http://www.sidefx.com/docs/houdini10.0/copy/instancing [sidefx.com]
http://www.sidefx.com/docs/houdini10.0/copy/varying [sidefx.com]
you can append copy sop after the pop network for that kind of thing
read this for more info
http://www.sidefx.com/docs/houdini10.0/copy/instancing [sidefx.com]
http://www.sidefx.com/docs/houdini10.0/copy/varying [sidefx.com]
-
- Quick Links