RenderMan RIB archive motion blur

[Magnus Pettersson]

I have some troubles exporting ribs the way i want in Houdini.

I have succeeded adding my point attributes into the rib with attribute node and under RenderMan tab in there. One thing im stuck with is motion blur. And the other is to export "sprite" as i have understood is patches in renderman and i think that is more complicated.

The test rib i have now looks kinda like this and is exported with the output rop renderman archive node:

# /obj/snow
ArchiveBegin "/obj/snow"     # {
    # Handle: '/obj/snow'
    Sides 2
    Points    # {
    "P" [-1.05654573441 0.325240373611 -4.48722743988 -0.570473492146 0.675292611122 1.23075318336]
    "varying float velocity" [0.264342665672 -0.250121951103]
    "varying float width" [0.0581937134266 0.059603381902]
    "constant string primtype" ["point"]
    "varying float spriterot" [-1.87584781647 18.9188842773]
        # }
ArchiveEnd    # }
AttributeBegin    # {
    # Geometry object /obj/snow
    Transform [1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1]
    Attribute "identifier" "string name" ["/obj/snow"]
    ReadArchive "/obj/snow"
AttributeEnd    # }

And the test rib i got from the renderman guy to use as reference for motion blur looks like this:

##RenderMan RIB
version 3.04
Color [1 1 1]
Opacity [1 1 1]
MotionBegin [0 1]
    Points "P" [-0.54035 0.447932 -0.522365 -0.50818 0.0745401 0.304513 -0.180791 0.0211549 0.220097] "constantwidth" [0.166667] "constant string primtype" ["point"] "vertex float ageNormPP" [0.0458254 0.0180436 -0.0131052]
    Points "P" [-0.797683 0.661252 -0.771132 -0.862796 0.126555 0.517006 -0.444537 0.0520167 0.541183] "constantwidth" [0.166667] "constant string primtype" ["point"] "vertex float ageNormPP" [0.0458254 0.0180436 -0.0131052]
MotionEnd 

So it has MotionBegin and the points translation two times on the different timesteps of the motionblur, how do i get this output from houdini?

And if someone has any ideas how to export the "sprites" from houdini heres a little cutout from a rib with patches:

TransformBegin
    MotionBegin [0 1]
    Translate -0.797683 0.661252 -0.771132
    Translate -1.05502 0.874572 -1.0199
    MotionEnd
    Patch "bilinear" "P" [-0.187906 -0.441726 0.519201 0.519201 -0.441726 -0.187906 -0.519201 0.441726 0.187906 0.187906 0.441726 -0.519201] "constant string primtype" ["point"] "constant float ageNormPP" [0.0458254]
TransformEnd 

[lisux]

I think you have to add some render properties to the RenderMan Archive operator, in the parameters tab, press the wheel button, select Edit Rendering Parameters.

From the list look for properties called allowmotionblur, geo_motionsamples, geo_velocityblur, and rib_motion01.

In the edit rendering parameters dialog, filter by geo to look for these parmaters

Add them to your parameters and test.

Hope this helps

[Magnus Pettersson]

I think you have to add some render properties to the RenderMan Archive operator, in the parameters tab, press the wheel button, select Edit Rendering Parameters.

From the list look for properties called allowmotionblur, geo_motionsamples, geo_velocityblur, and rib_motion01.

In the edit rendering parameters dialog, filter by geo to look for these parmaters

Add them to your parameters and test.

Hope this helps

Thanks Pablo! I think i got it working with the motion blur now. I had tried all of those attributes before but i only tried everything on the geo node and not the actual archive rop node!

I added now the allowmotionblur to the renderman archive node and then geo_velocityblur to the geo node and from the looks of the rib file it seems to work!

Soooo... Patches (sprites) anyone?

/Magnus