View dependent VrayFur

[tammo]

Hi!

My vray wish for christmas:

View dependent VrayFur.

You would be able to select a camera in the vray fur rollout.
The fur is then only generated were the camera is looking.
The detail of the fur is adjusted regarding the distance to the camera.

You would be able to make huge areas of grass and still have lots of details
even for camera fly-overs.

A succesful implementation of this feature is in the dreamscape sea surface object set to adaptive mesh:

[vlado]

The fur is already generated only when it is actually needed; the problem is that with GI, it is going to be needed everywhere (or at least in some parts outside the camera view).

Best regards,
Vlado

[tammo]

Is it really rendering less fur strands on faces that are far away from the camera?
Because i was never able to render a large field of grass.
If i cover the same area with patches of vray-proxy geometry grass it works without problems.

[duke2]

You'll never by able to render a huge field of grass with a hair system because each strand is it's own unique spline to generate geometry from. All the grass/mass geometry systems out there, like VRayScatter, ForestPro, Autograss use the VRayProxy, which is a single mesh scattered around a few thousand/billion times, so it's paging the same geometry.

[tammo]

Yes that is why i would like to have a view dependent hair system.
Far away from the camera it would only generate a few hairs per pixel.

Another idea would be to use the cameras near and far environment settings to manually set a maximum distance for hair generation in the modifier.

You could then use the ground texture in the distance instead of the Fur.

I already tried that with a falloff map in the density map slot set to distance blend but its not working.

[Mnietek2707]

You'll never by able to render a huge field of grass with a hair system because each strand is it's own unique spline to generate geometry from.

Is this necessary?
In many cases, a simplified version of vrayfur in which strands are
one object instanced many times (and randomly rotated, scaled) could do the job...

__________
sorry for my English

[vlado]

Actually, you can implement this yourself by using a falloff map in object mode (where the object is the camera) for the fur density. You can also map that to strand thickness, to preserve the apparent volume of the grass.

Best regards,
Vlado