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Pottuvoi

Member Since 20 Mar 2011
Offline Last Active Oct 21 2014 12:06 AM

#5172741 Grass Rendering Questions

Posted by Pottuvoi on 11 August 2014 - 05:07 AM

There was couple of nice blog posts about blue noise that might interest you.
http://mollyrocket.com/casey/stream_0014.html
http://mollyrocket.com/casey/stream_0015.html




#5119193 Cloud Rendering

Posted by Pottuvoi on 25 December 2013 - 08:45 AM

Here's a nice little page for slightly old but decent methods for cloud rendering and lighting, should be plenty of fast for current hardware. (there's descriptions for single and multis cattering methods, imposters, volume etc.)
http://vterrain.org/Atmosphere/Clouds/

 

The method which was used in Microsoft Flight Simulator 2004: A Century of Flight.

http://www.ofb.net/~eggplant/clouds/




#5067029 Space Partitioning on Sphere

Posted by Pottuvoi on 03 June 2013 - 02:09 AM

One easy way would be starting with cube and normalize the vertex posistions to a sphere.




#4965866 Cone Tracing and Path Tracing - differences.

Posted by Pottuvoi on 03 August 2012 - 09:52 AM

Oh, I have another question. If a cone intersects a voxel, then were is the hit point? Ray has no thickness, so it hits in one point, but cone has volume.

I'm quite sure that cone size is byproduct of mipmaps, voxels get bigger so basically ray gets 'volume' as well.


#4963349 Cone Tracing and Path Tracing - differences.

Posted by Pottuvoi on 26 July 2012 - 10:11 AM

Cone tracing of polygons is possible...but beam/cone tracing is quite different when using polygons.
Voxels simply make it easy as they are easily prefilterable, polygons are not.

Easiest way to get it to work with polygons is to voxelize them and use voxel cone tracing.. (which is apparently what Unreal Engine 4 does.)


#4963285 Cone Tracing and Path Tracing - differences.

Posted by Pottuvoi on 26 July 2012 - 07:08 AM

In cone tracing you sample a prefiltered geometry. (mipmaps)

Depending on radius of cone change to lower mipmap, thus when it hits you get sum of all information in the smaller voxels down the mipmap tree.
This is the reason you do not need to shoot so many rays/cones this way.

Older papers give more information on their cone-tracing..
http://www.icare3d.org/research-cat/publications/beyond-triangles-gigavoxels-effects-in-video-games.html


#4960140 Texturing large terrain

Posted by Pottuvoi on 17 July 2012 - 01:29 PM

After a quick skim this seems like a similar idea as mega texturing. The problem is that I can't have a large virtual texture because it would be too large to hand-paint/generate and store on disk. This is why I'm looking more at procedural splatting methods.

Mega/virtual texturing doesn't mean that everything must be hand painted.
You just create the data in whatever way you want instead of just loading it off disk. (splatting, procedural textures, baking GI data just in time.. etc.)

Battlefield 3 used splatting with virtual texturing quite nicely.
http://publications.dice.se/attachments/GDC12_Terrain_in_Battlefield3.pdf


#4856804 Relief mapping, slicing artifacts?

Posted by Pottuvoi on 02 September 2011 - 10:09 AM

There's also methods which are fast and can get correct intersection like quadtree displacement mapping.


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