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Member Since 30 Nov 2004
Offline Last Active Sep 29 2014 01:40 PM

Topics I've Started

What is PxFileBuf.h in Nvidia's APEX?

05 February 2013 - 01:31 AM



I wasn't sure whether to post this in Physics or API.. but it's API specific rather than physics know-how so I figured I'd post here.


I'm having issues with integrating APEX in to my project, however I've come across an include for a file called 'PxFileBuf.h' which I cannot find anywhere within either the PhyX or APEX folders.


I can't find anything about this file in regards to PhysX or APEX on Google so I wondered if anyone else had the same issue?  I was wondering if I'm being really simple.



Thanks for any help.

Vector Rotation

04 April 2012 - 12:05 AM

Hi everyone,

I've been struggling along with some vector rotation stuff, which I'm actually thinking is probably quite simple.. but I'm stuck in a mental rut (having only just gotten out of my last one..).

I'm trying to do collision testing of a set of capsules and a line. The line is perfectly placed now, but the capsule set isn't. I didn't post this in the game specific forum as it's a more general problem, but the vectors are being rotated from a skeleton (which is being rotated for rendering too).

When I render the skeleton/character I do these transforms..

glTranslatef(position.x, position.y, position.z); //Character position
glRotatef(90, -1.0f, 0, 0); //Rotate the model 90 so it moves along the Z axis
glRotatef(direction * 180 / PI -120, 0.0, 1.0, 0.0); //Rotate to the characters direction
glTranslatef(end.x, end.y, end.z) //The end position of the joint

Then I draw the character.

So I've been trying to re-create these transforms when building the capsules for testing. I did think about using a matrix, but I'm really not a maths person. I started by creating an 'origin' vector for the initial position, then for each capsule I had 'capBegin' and 'capEnd' to store the vector of both ends. However this is where I've gotten stuck, I can't decide/figure out how best to the get the rotations to work. Most of the rotations I've been doing have skewed the mesh, or moved them outside any viewable area.

I've been looking through google and here, but I'm either searching the wrong things or I'm not reading them right!

So I'm looking for a bit of guidance on how to do this. I'm very much open to criticism on my being silly, so long as it comes with some help on where I'm going wrong!

Thanks for reading.

Attack arcs

23 March 2012 - 03:22 PM

Hi everyone,

I've been trying to get my head around how to do something for ages and have completely gotten myself confused with it! The idea is very simple, as the solution probably is too! But I'll just say beforehand that my math skills are a bit lacking, so maybe that's how I've gotten myself muddled.

I want to create a triangle from a character of a specific distance every time they do something. There are three points to the triangle-

Point 1 is centred on the character
Point 2 is a distance of 5 in front of the character and 5 to it's left
Point 3 is a distance of 5 in front of the character and 5 to it's right
(Point 4 to complete the triangle is obviously just Point 1 again)

Now I can (obviously) work out Point 1, but it's figuring out the other two points that I'm having difficulty with - but I'm sure the solution is really simple! I just can't get my mind to think in a suitable manner.

If anyone could help me get out of this boggle I'd very appreciative! And more so if there's not too many jibes about me being a bit special.


Terrain (Geometry Clipmaps) and Data Loading

15 November 2011 - 09:50 AM

Hi everyone,

I've been working on a small personal project for a long time now and a while back I stumbled across Geometry Clipmaps for terrain rendering. I've (very slowly) been getting my head around how it all works on the rendering side of things. However I'm having some issues deciding how to produce the data from which to render my terrains. I've had a lot of different opinions on the most suitable approach and so I figured I'd come to a good source of facts and opinions!

I've mostly been focused on a large set of "chunked" files, all of these stored at the different resolutions that I might need. So if there are 9 levels display, then I'd have the entire terrain stored in 9 different sets of chunks, each in its own resolution.

Another idea I had was to just access one large file, but I'm not sure how suitable this would be considering the scale of the game world. For each of the higher levels (lower resolutions) I'd need to do checks at intervals, rather than every point. Is the searching time required by this going to be a big overhead that makes it impossible?

Also someone suggested just using a custom file format system, each file containing either a specific areas data for all levels or maybe all the data for one specific level?

As is probably quite obvious, I'm getting myself a bit confused a muddled with all the ideas. So please, any ideas (especially any that you guys have got working yourselves) are eagerly awaited!


Model Scaling

01 April 2011 - 04:07 AM

Hi all,

I have a, perhaps, silly question for everyone. It may well be an opinion rather than anything factual but I'm very interested to see what others think/do about this.

As with a lot of folk who try and do game dev on some level I learnt a lot using tutorials. The first type of model I ever had loaded in to a "game" was an MD2 model. One thing that always confused me was that they were always scaled down to 20% of their actual size, and this was the case across the majority of the MD2 tutorials I looked at. Now I structured my "game" around the size of the models, keeping them at 20%, and then later I added support for MD5 models. I scaled these to be of similar size to the MD2's, otherwise everything else would've been out of proportion. I'm trying to make my "game" a bit more stable and keep things easy to use/expand and that is why I'm thinking of trying to remove this constant scaling.

So my question is.. is it bad practice to have ALL the models scaled in this fashion? I can see obvious issues when you want to do any per-poly/per-vertex checks.. as the original data will all be 5x bigger. Does anyone else do this? If so, why?

Thanks for reading!