Normal maps Slow rendering

[mike_kennedy]

Hi there,
Our config is
Max 9 64, Vray 1.5 SP1 on XP 64, 8 gigs across the board.

We are finding when we use normal maps that the renderings slow down by a significant margin. Any ideas?
Cheers
Mike Kennedy

[vlado]

Normal mapping is generally implemented by 3ds Max; not quite sure what the issue is, but it might be related to the geometry it is applied on.

Best regards,
Vlado

[duke2]

I found this as well and stopped using them. I'll put a sample together over the weekend.

[mike_kennedy]

Any Feedback on this, If we use Normal Maps in any scene we see a huge jump in render times.
Cheers
Mike Kennedy

[RErender]

more so than a heavy bump? They complicate the gi solution quite a bit over a smooth surface...

We use normal maps quite a bit and they seem pretty quick, faster than displacement.

[vlado]

more so than a heavy bump? They complicate the gi solution quite a bit over a smooth surface...

When using the irradiance map, V-Ray actually calculates the GI based on the original surface (without bump mapping). The bump mapping is applied only in the final rendering/interpolation phase. So the slowdown is probably somewhere else.

Best regards,
Vlado

[RErender]

Good to know, I swear I have seen a difference though, has it always been this way? Same for LC?

Maybe it was due to glossy reflections...

[vlado]

This is true for the light cache as well, yes. It has always been this way too.

Best regards,
Vlado

[stevesideas]

Is there a good normal maps tutorial..I still dont fully understand how to implement them in vray.

[vlado]

They work with V-Ray in exactly the same way as they work with the scanline renderer and mental ray in 3ds Max.

Best regards,
Vlado