Projective Textures, Shadows? how?
Author
Ok I have a kind of map. that I want shadowed. the main problem was that i didn''t consider shadowing earier. (big mistake) anyway when looking over ways to do it, I considered what I did in the past. Sloap Terrain light - almost but not quite. Shadow volumes, hard to get silloett, then I saw The new Shadow projections that I have seen.
But I have never used these or projective textures, nor have I done this type of shadowing. Could someone spare a moment and point out how to do this. thanks.
sorry for any Typos, Im in a bit of a rush to type this out.
its similar to lightmaps, search for projective texturing, and project a white bitmap from your sun, it''ll show up as shadows.
Author
Ok I looked it up and after a long time of messing with it, I got it to project some screen shot of my game onto my ground, just for the moment at least. But it ends up tiled strangly and dosn''t quite look how I would have planed, but thats ok for the moment, I guess its just because My Camera Dosn''t see all of the ground, I''ll fix that next when I can. But before I do that, I''ll ask this question,
Shadowing, I don''t see how projecting a white bitmap will get me anywhere, All im going to get is a totally white ground, Correct? there needs to be some kind of depth interaction or something dosn''t there?
Could some one enlighten me furture on this subject?
Shadowing, I don''t see how projecting a white bitmap will get me anywhere, All im going to get is a totally white ground, Correct? there needs to be some kind of depth interaction or something dosn''t there?
Could some one enlighten me furture on this subject?
look into GL_ARB_shadow its real easy
there is a delphi demo on delphi3d.net
check out my thread GL_ARB_shadow its in this opengl forum
there is a delphi demo on delphi3d.net
check out my thread GL_ARB_shadow its in this opengl forum
Author
Ok I looked it over at Delphi3d and I have come to the conclustion that their method is not quite what I expected, They just use a white textuer with a black teapot rendared into it, I thought you could render a depth buffer of some kind into a texture and use that compared to the projection values, and that could be used to generate the shadows. I came to this conclusion after reading some stuff from nvidia, and after seeing their demos.
is there a way to do this, because I don''t have any Specifed Shadow Casters. I have one Shadow Caster One Shadow Reciver. Meaning Its a kind of terrain, but its not a Height map.
Thanks.
is there a way to do this, because I don''t have any Specifed Shadow Casters. I have one Shadow Caster One Shadow Reciver. Meaning Its a kind of terrain, but its not a Height map.
Thanks.
The white texture and black teapot was probably the depthbuffer.. (not a caster + reciever). This technique should work nice on your landscape.
Author
He does use caster-reciver, he draws the Teapot in black and the rest of the screen in white, then projects this onto the reciver to create a shadow of the teapot.
I currently only know how to use Projective textures. Could someone help me with how I would use an image from the depthbuffer of my camera to create Shadows?
...procedure TPSForm.UpdateShadow;begin // Set a square viewport for the texture: glViewport(0, 0, S_SIZE, S_SIZE); glMatrixMode(GL_PROJECTION); glLoadIdentity; gluPerspective(90, 1, 1, 1000); glMatrixMode(GL_MODELVIEW); // Render the teapot black-on-white: glDisable(GL_LIGHTING); glColor3f(0, 0, 0); glClearColor(1, 1, 1, 1); glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT); glLoadIdentity; gluLookAt(LCF_O.x, LCF_O.y, LCF_O.z, LCF_Z.x, LCF_Z.y, LCF_Z.z, LCF_Y.x, LCF_Y.y, LCF_Y.z); DrawTeapot; glBindTexture(GL_TEXTURE_2D, shadow); glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, S_SIZE, S_SIZE); // Re-enable regular lighting: glEnable(GL_LIGHTING); glColor3f(1, 1, 1); glClearColor(0, 0, 0, 1); // Reset view: glViewport(0, 0, ClientWidth, ClientHeight); glMatrixMode(GL_PROJECTION); glLoadIdentity; gluPerspective(60, ClientWidth/ClientHeight, 1, 1000); glMatrixMode(GL_MODELVIEW);end;... I currently only know how to use Projective textures. Could someone help me with how I would use an image from the depthbuffer of my camera to create Shadows?
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