Search found 14 matches

by olliej
Thu May 16, 2019 2:36 am
Forum: Visuals, Tools, Demos & Sources
Topic: Glitch Pictures anyone?
Replies: 81
Views: 112088

Re: Glitch Pictures anyone?

I vaguely recall the problem being texture loading related

Image
by olliej
Fri Feb 22, 2019 3:56 am
Forum: Visuals, Tools, Demos & Sources
Topic: My first real RT
Replies: 0
Views: 343

My first real RT

I decided to learn rust by writing a raytracer, and finally got to the point of having a ray tracer with a semi-decent feature set:
Image

You can see all the standard photon mapping problems -- halos at the top of the arch, and photon bleeding on the back wall.
by olliej
Thu Feb 21, 2019 7:07 pm
Forum: General Development
Topic: Bump mapping/computing normal derivatives
Replies: 1
Views: 528

Re: Bump mapping/computing normal derivatives

And as is the nature of such posts, it made me think of a potential issue, and I discovered it computed inverted dpdu/dpdv for clockwise vs counterclockwise triangle definitions (I think w.r.t triangles with explicitly specified normals)
by olliej
Thu Feb 21, 2019 8:10 am
Forum: General Development
Topic: Bump mapping/computing normal derivatives
Replies: 1
Views: 528

Bump mapping/computing normal derivatives

I've been working on bump mapping in my RT (technically not my first, but definitely my first attempt to create an actually capable one). A lot of basic googling seems to imply the use of ray differentials, but I'm not sure I understand why that is necessary - obviously they have benefits for other ...
by olliej
Thu Feb 21, 2019 1:13 am
Forum: Visuals, Tools, Demos & Sources
Topic: Optix 6.0 Path Tracing demo
Replies: 8
Views: 5345

Re: Optix 6.0 Path Tracing demo

Okie dokie :) I'm still trying to work out what it should be doing (this is my first real attempt to implement PM). I'm getting a huge blow out on the direct photons, and a rapid drop in the propagation following the first bounce. (I'd search the board but photon mapping is apparently too common to ...
by olliej
Wed Feb 20, 2019 6:58 am
Forum: Visuals, Tools, Demos & Sources
Topic: Optix 6.0 Path Tracing demo
Replies: 8
Views: 5345

Re: Optix 6.0 Path Tracing demo

@jbikker: ok, possibly dumb question - how do you handle convert the emission coefficients from the wavefront into optix? I'm doing the dumbest thing possible with and doing ke * light colour ?
by olliej
Wed Feb 20, 2019 2:27 am
Forum: Visuals, Tools, Demos & Sources
Topic: Optix 6.0 Path Tracing demo
Replies: 8
Views: 5345

Re: Optix 6.0 Path Tracing demo

It is indeed -- I wonder if I dismissed it due to my RT not being able to handle it earlier.

Now to work out why my photon mapping is weird and blown out.
by olliej
Tue Feb 19, 2019 3:24 am
Forum: Visuals, Tools, Demos & Sources
Topic: Optix 6.0 Path Tracing demo
Replies: 8
Views: 5345

Re: Optix 6.0 Path Tracing demo

Would you mind if I used your version of the sponza model to test my own renderer?

The various open licensed versions I've found lack the detailing and have some questionable texture coords.

Also it's nice to be able to be able to compare exact scene rendering to an actual good renderer :)
by olliej
Mon Feb 11, 2019 6:08 pm
Forum: General Development
Topic: Performance issues with Wald&havran's nlogn kdtree construction
Replies: 5
Views: 959

Re: Performance issues with Wald&havran's nlogn kdtree construction

And immediately following that post I remembered Quickselect as a thing that existed. *sigh*
by olliej
Mon Feb 11, 2019 6:05 pm
Forum: General Development
Topic: Performance issues with Wald&havran's nlogn kdtree construction
Replies: 5
Views: 959

Re: Performance issues with Wald&havran's nlogn kdtree construction

The only O(N) median searches I'm aware of require a sorted input, which (as we end up functionally alternative split axis) requires a sort at each level of recursion, which gives you logN nLogN operations. I *could* do a radix sort which would technically make it linear, but I suspect I would fall ...