   Gradually expand texture
  Okay, this seems like a tricky one. I've searched around and haven't come up with anything.What I have is a sphere with no texture. I have a missile which gets shot at it. What I want is for a texture to start getting applied from the collision site until it eventually covers the entire sphere.At the moment, I start without setting any texture coordinates. Then what I do it is stop the missile where it collides with the earth and set a tiny radius (with the center of this new 'sphere' being the collision spot) which expands somewhat each frame. In the sphere code, I check which vertexes (I only check the first vertex for each quad in the sphere) are within the expanding sphere. If it is, I apply the coordinates of that quad.While it works sorta properly, the effect looks quite lame and not very pretty. Is there any 'nicer' way of doing this?   
  If I had a better idea of what your effect looks like I could maybe throw out some ideas, but it is kind of hard to improve on your idea with so little information.Some pictures or maybe even a short youtube video would probably go a long way to getting you some better ideas.Also an important question: are you willing to use shaders? That will make a big difference.   ;  The project is on my other laptop and I won't be home for about another six hours. The closest thing I can think of is the healing in Prince of Persia. Here's a video:Of course, I don't want it to look as good as that, but the gradual changing of the ground should give you an idea of what I'm after. If I could get get the smooth transition without all the particle effects, that would great.Regarding shaders, I haven't done any HLSL programming before and would rather not having to use it. If it's rather easy, I don't mind, but I'm on a very tight schedule with this project so 'good enough' is all I'm really after.   ;  Hmm well without shaders I can't think of too many options. The problem with your approach is that unless you have a super finely tesselated mesh its going to be "chunky", or whenever you add a new vertex a triangle is just going to change texture of that triangle all at once, which is jerky and unappealing.If you use a simple shader you could just fade between the pre-hit texture and the post-impact texture based on time and distance from the impact point, which would be really easy and much more smooth effect (it would be a per pixel calculation instead of per vertex).If you have to do this in fixed function pipeline, I would suggest that you maybe try to use some alpha blending such that when you first add a new vertex into your textured area, to start it with a small alpha value, like 0.05 or something, and then gradually increase it. This would look a little bit smoother, but you'll still see the triangulation.EDIT: Also HLSL is for DirectX, GLSL is the OpenGL equivalent.   ;  I think you want an effect like the one at the 15th second of this "Titan AE" video.">youtube Titan AE videoIt should be possible to do it using a fully UV-mapped sphere and a texture with a small colored dot at the center. You just have to apply a scale in texture space to make the dot grow and cover more and more of the sphere (you will also need to offset you texture so the dot is always centered at the impact point).;  I think you might be able to pull it off with glTexEnv*(), but it's been a while since I've used it, so I'm not sure I'll be of much more help than that. Basically it lets you set up some fancy blending without having to resort to shaders.[EDIT]Forgot the following quote on the link...   ;  You might want to be more clear, do you want to grow the texture over the sphere by stretching it, or do you want a constant texture map over entire sphere and gradually reveal the texture? Alfith's idea might be the right one if you're after the former, but I was assuming (perhaps incorrectly) that you were interested in the latter.   ;  Yeah, the second is what I was after.Taking from Alfith's idea, if I had a greyish pixel on the texture at 0,0 or something, and then set the unrevealed part of the sphere to that, would that work?This is closer to the effect I want to achieve (on a much more basic level, though): www.youtube.com%2Fwatch%3Fv%3DQXbWCrzWJo4;Quote:Original post by NRafThis is closer to the effect I want to achieve (on a much more basic level, though): www.youtube.com%2Fwatch%3Fv%3DQXbWCrzWJo4Fixed link: ">click me.   ;  Actually multitexturing might be appropriate here. You could wrap the sphere entirely in its final texture, and use another mask texture to reveal it.It would take a little bit of trial and error to get right, but it might work. Your mask texture could be 1 where you reveal the final texture, and zero otherwise where its not shown. You could center the mask texture at your impact site, and then expand the texture by scaling the GL_TEXTURE_MATRIX via glScale/glLoadMatrix. I've no idea how well this will work in practice and it might be difficult to get the UV's right for the entire sphere, but it might be an option.