[HOU-3967] Houdini spectra cusp problems

[PUFFBALL]

Hi all

Recently enjoying the new spectra features to access all the details of the houdini ocean spectrum and get some great ocean details (mantra style) - however ive noticed some issue with the cusp coming out from the spectra node. It appears to flicker and pulsate over random values. Its a float value and so ive tried remapping, using float to color and re-ranging and remapping via ramps and clamps. Ive rendered the raw output into a material and can see it pulsating/flickering without any manipulation. Is there something i should be doing to this float or is this a potential bug?

Attached a clip that illustrates this issue. Interested in what may be happening here. Also as a side note - the displacment is only clean and usable when the sampling is set to spherical on the spectra node - otherwise its a faceted mess.

Thanks

[bdancer]

Any luck for the whole setup to be shared? It'll be easier to track the issue this way. You could send it to the email in my signature (we could sign NDA if needed).

[PUFFBALL]

File sent. Many thanks for looking into it

[david.anastacio]

Hi all

Recently enjoying the new spectra features to access all the details of the houdini ocean spectrum and get some great ocean details (mantra style) - however ive noticed some issue with the cusp coming out from the spectra node. It appears to flicker and pulsate over random values. Its a float value and so ive tried remapping, using float to color and re-ranging and remapping via ramps and clamps. Ive rendered the raw output into a material and can see it pulsating/flickering without any manipulation. Is there something i should be doing to this float or is this a potential bug?

Attached a clip that illustrates this issue. Interested in what may be happening here. Also as a side note - the displacment is only clean and usable when the sampling is set to spherical on the spectra node - otherwise its a faceted mess.

Thanks

Hi,

This is something I previously reported bdancer, Gosho.Genchev has a test scene with this issue from August 6th.
Additionally PUFFBALL, with ALL V-Ray 6.1 builds, ocean spectra renders incredibly slow, this was flagged as logged as HOU-3952, I believe this is nearly fixed.
And finally the displacement dicing is also an issue with the spectra, the amount of geometry generated by the dicing decreases dramatically when Motion blur is turned ON.

Gosho has example scenes for all the issues mentioned

Example of render slow down, with V-Ray 6.0:


Example of render slow down, with V-Ray 6.1:



Example with Motion Blur OFF:


Example with Motion Blur ON:



Best,
David.

[Gosho.Genchev]

Hey,

Yes, we are aware of the cusp flicker - we had to work through the slowdown issue David mentioned above which was resolved last week. We'll try to take care of the flickering cusp in the days to follow.

Best regards!