Arnold not rendering pscale from houdini

[molora8946]

So I have dived into using Houdini as X-Particles are slower than a snail, I have completed a particle system that I have created for a client. I have exported from Houdini with the relevant attributes such as pscale and Cd using the rop alembic. I then imported it into C4D and created an Arnold tp group in which I have started in the export field to use: Cd pscale, I then created material and added a user data RGB with Cd assigned which has worked but why are my particles not the correct size?

[molora8946]

this xpresso is attached to a blank null

[peter_horvath]

Have you tried setting Size instead of Scale?

[molora8946]

yes I have @peter_horvath unfortunatly I have had no luck I am using Arnold c4dta 4.3.0

[peter_horvath]

Could you please check two things?

• Is the Size attribute picked up by Arnold? If you connect a Constant to the Size, does it render as expected?
• Does the pscale channel has the correct data? For instance if you connect it to the Color with a mapping of (0,1)? Or read via a user_data_float shader in the material?

[molora8946]

@peter_horvath I think I've managed to fix it I've set xpresso on expression priority (it was on animation before) which made my points go tiny and then in Arnold tp I've gone to radius multiplier and X100 scale which seems to have worked will post again if I have any issues, but this shouldn't take that long to do, the most complex part of this was meant to be Houdini and not me trying to render it in c4d in which I am definitely more confident in LOL.

[peter_horvath]

Glad to hear it's working. Xpresso priority can definitely affect the behavior.

[molora8946]

is there any particular reason why the first frame on IPR looks perfect but when I'm actually rendering it the particle sizes seem to go 1000x and then 2nd frame it's all back to normal again? @peter_horvath 

[peter_horvath]

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@molora8946 wrote:

is there any particular reason why the first frame on IPR looks perfect but when I'm actually rendering it the particle sizes seem to go 1000x and then 2nd frame it's all back to normal again?

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Not that I know of. In theory each frame is rendered the same, using the same code on the plugin side. Maybe something in the scene?

[molora8946]

thanks again just very strange all frames are perfect just the first one that looks like 3 big balls intersecting madness main thing is i don't mind losing one frame lol