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SmellyIrishMan

Member Since 12 Oct 2006
Offline Last Active Oct 02 2013 09:00 PM

Posts I've Made

In Topic: How should I do environment reveal/texture blending?

08 July 2011 - 06:36 AM

Cheers Rick,

While I'm not a master I have a good grip, both theoretically and practically, on all of the methods you've mentioned. I guess I was just looking for some suggestions as to how I could approach the problem and your post has certainly pointed out some new things for me to think about so thanks for the post, it's very much appreciated!

In Topic: Vertices, Normals and Indices

10 June 2011 - 07:58 AM

Think about a cube also.

A cube has 8 vertices, but there needs to be 3 normals at each of those vertices (for a total of 24 normals) if you want to get accurate shading results. Have a look at this image for an example of that. Cube with proper normals. These additional normals are typically created when the angle between two normals on the same vertex break a certain threshold.

If you had just one averaged normal at each vertex then you get this and that's going to give you some funky shading.

In Topic: Particle Effect

07 June 2011 - 08:08 AM

how to give particle a blast effect 2d.

eg: 10 particles and what sort of velocity should i give to make it appear as blast???


You need to analyse the effect that you're looking to accomplish and see what type of velocity/positioning etc... that it displays.

So taking your example of a blast... well, normally a blast comes from a very specific point, so the initial position of the particles will be very close to one another and to the source of the blast. Then lets look at the velocity, unless the blast is from something very specific then an explosion typically has not specific direction and instead just spread out in all directions, so you should distribute your particles velocity over a unit circle.

Have a look at this for example; blast effect

With particles (and most simulation) you need to study your target, figure out its general properties and then try to match these.

In Topic: How to converse tangential velocity

04 April 2010 - 05:31 AM

So I got around to messing about with this again today and managed to come up with this;

originalVelocity = strand.Links[i].PhysicsEntity.linearVelocity;
normalisedVelocity = new Vector3(originalVelocity.X, originalVelocity.Y, originalVelocity.Z);
normalisedVelocity.Normalize();
strand.Links[i].PhysicsEntity.linearVelocity = originalVelocity - (contactNormal * Vector3.Dot(contactNormal, normalisedVelocity));
strand.Links[i].PhysicsEntity.linearVelocity *= 0.9f;

So I'm checking the angle of penetration and removing this from the velocity in order to just get the tangential quantity. The simulation runs a whole lot smoother now anyway, so I'm happy.

In Topic: Float subtraction error.

02 February 2007 - 04:26 AM

Noted Unbeliever, I appreciate the advice.

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