[Sidefx-houdini-list] Curves normals

Peter Bowmar pbowmar at gmail.com
Sat Aug 28 07:33:27 EDT 2010


Indeed, there is a new property that turns on/off shading curves as
surfaces. I don't remember what it's called though...

On 28 August 2010 01:34, Louis Dunlevy <louisdunlevy at gmail.com> wrote:
> actually I betcha it's just a new default rendering parameter for that
> optimisation that was mentioned earlier, you can probably switch it back
> to the old method..
>
> On 08/28/10 00:58, Pablo Giménez wrote:
>> Yes definitely seems to be a bug in H11.0.446.9 , yes you got it is
>> the current production version!
>> Latest daily build work well and creates the s coordinate properly.
>> H10 also works fine.
>> Just in case somebody else is havign a similar problem.
>>
>> 2010/8/26 Louis Dunlevy<louisdunlevy at gmail.com>:
>>
>>> parametric s should not be zero. If it is, I'm thinking it may be a bug
>>>
>>> On 27/08/10 03:02, Pablo Giménez wrote:
>>>
>>>> Hi Andrew.
>>>> I have done similar things for other stuff, but my problem is that the
>>>> s coordinate is constant 0 for all the points in the curve geometry.
>>>> The t is fine, going from 0 to 1 along the curve lenght, but s is
>>>> supposed to be along the curve "cross sections" width, and this is not
>>>> happening.
>>>> With a proper s coordinate along the width of the curve would be easy
>>>> to fake a rounded look.
>>>> cheers
>>>>
>>>> 2010/8/26 Andrew D Lyons<tstexture at gmail.com>:
>>>>
>>>>
>>>>> I did this recently to generate fur sprites. If you get the curve
>>>>> tangent and stack some cross products with another version of the
>>>>> curve with normals hard coded to point towards the camera (or some
>>>>> cardinal axis) then you should be able to derive a normal that is
>>>>> always pointing in a general direction - but which follows the
>>>>> contours of the curve.
>>>>>
>>>>> 2010/8/26 Pablo Giménez<pablogipi at gmail.com>:
>>>>>
>>>>>
>>>>>> Hi.
>>>>>> I am rendering some poly lines as curves, using the 'width' attribute
>>>>>> to control every filament width.
>>>>>> That's all right.
>>>>>> Problem is that this geometry is created at render time and the
>>>>>> normals and texture coordinates are a little bit odd.
>>>>>> My main problem is that Mantra creates the needed geometry using the
>>>>>> width attribute but seems that is only shading the original curve
>>>>>> attributes.
>>>>>> I mean the hair geometry is created extendin the shaded point,
>>>>>> perpendicular to the point of view, and the new geo seems to use the
>>>>>> same shading as the original point.
>>>>>> Is similar to what happens with points rendering, where the point is
>>>>>> shaded once, and then all the geometry created at render time around
>>>>>> the origian lpoint use the same shading from the original one.
>>>>>> So you don't have proper normals to make for instance a diffuse
>>>>>> lighting that gives you some "rounded" look.
>>>>>> I have tried the hairNormalVOP, creating my own tangents, created
>>>>>> texture coordinates with s going along the hair line from 0 to 1, but
>>>>>> the normals I got are just pointin towards camera, they are not doing
>>>>>> the "Rounding2 effect that is suppose to do this operator.
>>>>>> So is there any way to go away from the planar look of curves shading,
>>>>>> any way to have sense whre you shading point is in the new created
>>>>>> gemetry so you can for instance fake normals o apply any othe rtrick.
>>>>>> Thanks
>>>>>> --
>>>>>> Un saludo
>>>>>> Best Regards
>>>>>> Pablo Giménez
>>>>>> _______________________________________________
>>>>>> Sidefx-houdini-list mailing list
>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>> =======================================
>>>>> Andrew D Lyons | Digital Artist | http://www.tstex.com
>>>>> =======================================
>>>>> _______________________________________________
>>>>> Sidefx-houdini-list mailing list
>>>>> Sidefx-houdini-list at sidefx.com
>>>>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>> _______________________________________________
>>> Sidefx-houdini-list mailing list
>>> Sidefx-houdini-list at sidefx.com
>>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>>
>>>
>>
>>
>>
>
> _______________________________________________
> Sidefx-houdini-list mailing list
> Sidefx-houdini-list at sidefx.com
> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>



-- 
No, I am not on Facebook.



More information about the Sidefx-houdini-list mailing list