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rumpfi88

Member Since 30 Nov 2009
Offline Last Active Jun 22 2016 01:47 PM

Posts I've Made

In Topic: Triangle-AABB intersection test

06 September 2015 - 05:54 PM

I'm done with implementation: I have the following informations and comparisions:

 

# Objects: 4

# Triangles: 34,378

Render method: Raycasting

Render size: 640x480

 

Time without Octree: ca. 8  minutes

Time with Octree: 35 seconds (15s for loading and building, 20s for rendering).

 

And of course, the results look the same ^^. Thx a lot for your advices.


In Topic: Triangle-AABB intersection test

31 August 2015 - 12:58 PM

it seems the whole algorithm is easier to understand when transforming the triangle so that AABB's center is at zero-point. I go with SAT.


In Topic: Triangle-AABB intersection test

31 August 2015 - 02:11 AM

You colud use the "separate axis algorithm". Depending on the case I think that it is possible to get away only with "is every vertex from the triangle in the box" test... not sure

 

I can't just depend on assumptions, a polygon's triangle might miss that way and then I have a big hole in my rendered object. I'd also like like to avoid transformations needed for SAA.

 

 

 

You can find Triangle-AABB intersection test in MathGeoLib, with references to sources. See

 

 

Thx, I can use that as inspiration, but I intend to avoid extern libraries in my framework. It's an educational purpose and it won't help my readers if I use something else.

 

@MCapousek

 

Your algorithm seems compact and not as complicated as MathGeoLib's version where they consider existing defines. I'll also use that as inspritation. But when you use 3 points for a triangle, there is no need to add normal and constant as parameters, you can calculate them from these 3 points.

 

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With so many supports I speak my thanks. I can finally accelerate raycasting/raytracing algorithm in my framework


In Topic: One or multiple octrees

25 August 2015 - 05:18 PM

I only analysed Wavefront OBJ/MTL files and partly 3DS Max files.I don't know how vrmesh will help me with that.

The purpose of my framework is to do everything with the support of high quality graphic libraries. It shall help students to understand render algorithms.


In Topic: One or multiple octrees

25 August 2015 - 10:36 AM

Ok thx. After implementation I'll add that method in my blog.


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