Houdini Fur

[mohit]

Hi guys,

I am relatively very new to Houdini and would like to seek help from all you Houdini Masters.

I would like to know:

How Can I achieve the original color of my texture map in Houdini Fur because when I try to apply my color map I don't get the desired result which I suppose is mainly due to the color ramp provided in the diffuse section of Fur shader.If I make it white it make texture too bright which is kind of multiplier.

Also I would like to know if some one can describe the function and implication of blend color map ramp in fur shader, unfortunately Houdini's help doesn't provide much info related to its' function and use.

I would also like to know how can I generate or take out the length map as an image file so that I can further make necessary adjustments to the map in another paint programe such as Photoshop.

Does Houdini support feature such as UV set which is very helpful in software such as MAYA for distributing and using UV space in more appropriate manner.

Can we use custom curves with Houdini's Fur, if yes then how what is the procedure for it.

How can I implement new hair model with Houdini.

Hope you guys would disregard my lack of knowledge of Houdini and would come forward with some reply for my better understanding of Houdini.

[brianburke]

How Can I achieve the original color of my texture map in Houdini Fur because when I try to apply my color map I don't get the desired result which I suppose is mainly due to the color ramp provided in the diffuse section of Fur shader.If I make it white it make texture too bright which is kind of multiplier.

try starting from a new 'material shader builder shop' with only a lighting component (pysically based hair model or surface model with hair normal) and a texture read. building a fresh shader really simplifies things and allows you to add only the features you need to your fur shader.

I would also like to know how can I generate or take out the length map as an image file so that I can further make necessary adjustments to the map in another paint programe such as Photoshop.

mantra can render to texture space. if you create a simple shader that renders length as color, you can use the 'uv render object' parameter on the mantra rop to render your length attribute as a texture. you can then read it back in as a length map.

Does Houdini support feature such as UV set which is very helpful in software such as MAYA for distributing and using UV space in more appropriate manner.

you can create an arbitrary number of uv layers. you could for example make uv attributes called uv1 uv2 uv3 uv4 uv5 each with different layouts. you can also arrange your uvs beyond 0-1 space in different tiles and use different maps for each udim.

Can we use custom curves with Houdini's Fur, if yes then how what is the procedure for it.

as long as the number of curves matches the number of points on your skin mesh and the curves are identical to each other in topology they can be used as guide curves for houdini fur. it is possible to create guide curves in maya and import them into houdini.

How can I implement new hair model with Houdini.

i can't really imagine needing to do this, since the new marschner stuff and the traditional isotropic+hair spec models work pretty well, but any kind of custom shading model can be written in vex as an illuminance loop.

good luck. houdini fur is rad!

[mohit]

Thanks Brian Burke,

Can Anyone share any file related to my query

"Does Houdini support feature such as UV set which is very helpful in software such as MAYA for distributing and using UV space in more appropriate manner. "

Also I find that rendering UV as texture space is camera dependant which I think is not the right, Please correct me if I am wrong ,Being from Maya background I find it much simpler and correct to export you maps for Fur and easily change them.

[anim]

what do you mean by UV set as in maya? what exactly is it used for?

in houdini you base distribution using groups and attributes on skin geometry like rest, area or furdensity

you can of course promote UVs to hair and in that case have full control over your textures or hair shape using UVs or other attributes

length might be a little tricky, for rough cut use various lengths on guide curves, then for per hair length, maybe easiest is scaling hair using hair origin as a pivot, which is not exactly cutting the hair length, but it can be used in many cases

you may find some helpful info in docs, as well as some examples

and there may be few fur discussions on forums as well

but essentially, you can use CVEX shaders to alter fur density per hair as well as overall shape of each hair and to create various attributes for shading

what do you mean rendering UVs is camera dependent?

if UVs exist on hair geometry, they are not camera dependent, in other words they stick to the geometry

and when you are crossposting between forums it's better to reference to one thread so that full discussion is kept on one place, it may as well save some time to somebody who is replying since it might be already answered on other post

...

as long as the number of curves matches the number of points on your skin mesh and the curves are identical to each other in topology they can be used as guide curves for houdini fur. it is possible to create guide curves in maya and import them into houdini.

...

this is no longer necessary as long as each guide has float3 primitive attribute 'guideorigin'

that will be used to interpolate among them within guideradius from skin surface

[mohit]

By UV Sets I Mean in Maya UV's works best in 0-1 space but packing all the UVs in one space is not good idea so We use UV sets for assigning UV's in better way with the help of different UV sets so each UV gets it's 0-1 space and works best for Better texture Painting and detailing.

It may not be related to Fur in Houdini but for Texturing it is very useful also I am bit confused how it will work when I try to assign texture maps to Fur.

Also As I asked before if I require my painted texture for fur length,etc and I would want to tweak those maps in third party softwares like photoshop ,How can I achieve this. The solution comes that I should render it as 'uv render object' but I am concerned that it is camera dependent means it depends on camera angle camera clipping etc.