Search found 46 matches

by dr_eck
Mon Mar 26, 2012 5:27 pm
Forum: General Development
Topic: Nvidia limiting gtx680 compute speed?
Replies: 20
Views: 17622

Re: Nvidia limiting gtx680 compute speed?

I'm confused. According to slide 14 of this presentation http://www.nvidia.com/docs/IO/113297/ISC-Briefing-Sumit-June11-Final.pdf , Kepler is supposed to have almost 3X the DP FLOPS/W of Fermi. Yes, it burns fewer Watts, but I was expecting at least 2X the performance. Is it just the OpenCL compiler...
by dr_eck
Wed Jan 25, 2012 5:53 pm
Forum: General Development
Topic: Dissapointing building times from lbvh gpu based builder
Replies: 35
Views: 27923

Re: Dissapointing building times from lbvh gpu based builder

Optix now has a GPU based HLBVH builder, as of version 2.5. Has anyone tried to benchmark it yet?
Does anyone know if it is work queue based or original?
by dr_eck
Thu Jan 19, 2012 4:22 pm
Forum: General Development
Topic: Dissapointing building times from lbvh gpu based builder
Replies: 35
Views: 27923

Re: Dissapointing building times from lbvh gpu based builder

Both consistency and bias are important concepts for a physically based ray tracer. Just for review: a consistent ray tracer will converge to the correct solution if enough rays are traced. Fewer rays will only result in noise. An unbiased ray tracer will give a result that is statistically accurate...
by dr_eck
Wed Jan 18, 2012 5:18 pm
Forum: General Development
Topic: Dissapointing building times from lbvh gpu based builder
Replies: 35
Views: 27923

Re: Dissapointing building times from lbvh gpu based builder

@outofspace Thanks for the pointer to Garanzha's HLBVH paper. http://garanzha.com/default.aspx The BVH build times are remarkable.

You can also add me to the list of supporters for "physically based".
by dr_eck
Mon Jan 09, 2012 5:21 pm
Forum: ompf2
Topic: Vote for a new domain name for your favorite forum!
Replies: 32
Views: 33591

Re: Suggest a new domain name for your favorite forum!

My son's Latin teacher (that would be me :) ) prefers rtfora to rtforums, but both have the problem of having 4 syllables. Raytalk rolls off the tongue more easily. Raydev is almost as good.
by dr_eck
Tue Dec 20, 2011 7:29 pm
Forum: General Development
Topic: Preetham Sun, spectral rendering
Replies: 15
Views: 11701

Re: Preetham Sun, spectral rendering

First, I assume that you know how to convert between lumens/m^2/sr and cd/m^2 and cm^2 to m^2. ;) The challenge is to convert from Watts to lumens. This conversion factor depends on the wavelength, because lumens take the response of the human eye into account. Thus, to convert from W/um (I use 'u' ...