[SOLVED] Circle shadow under character technique

[kjuanlu]

Hello, I'm trying to find information on the technique used to paint a circle shadow under the character like this:



But I dont know how the technique is called, and how to implement it on Ogre iPhone Port (without using stencil buffer).

Anyone know his name?

Someone knows how it was implemented in the ancient games?.

Thanks

[kjuanlu]

Render to Texture?

Render to Texture is support on OpenGL ES1?

[masterfalcon]

Yeah, rendering to a texture does work. One of the tutorial shows how to set it up, http://www.ogre3d.org/tikiwiki/Intermediate+Tutorial+7

That may be a bit much though, all you really need is to project a texture onto the terrain below.

[kjuanlu]

Thanks, when I have something I'll show

[kjuanlu]

http://www.ogre3d.org/tikiwiki/tiki-ind ... Tutorial+6

And projective decal?

[Praetor]

They are called "blob" shadows.

[kjuanlu]

Have been all day trying to get this technique with projective decal (Intermediate tutorial 6), and others tutorials (terrainDecal etc..), but no way.

It also has to be difficult to know the coordinates of the mesh. And also, if it depends on the material, UVWrap objects does not help, and shadow repeats in every object with this material. I have a Lightmap in the second tex_coord for a single mesh, that represents all the static scene.

I have to find another solution, I'm going crazy after so many hours in front of monitor.

I attach the results with a temp decal (its a circle, it shows wrong), (I will change with a bob shadow), and my scene. The decal image dont show correctly. All the scene is a single mesh (with two sub-materials). I try to apply de decal only in one sub-material.

In conclusion, I have no idea where to go

PD: The screenshot is take using this code for projective decal: http://www.ogre3d.org/addonforums/viewtopic.php?t=6371

[kjuanlu]

I try it with decals, with ray cast to polygon level, and now, I try it with a simple plane and a texture with alpha channel.
It runs good, but now i have another problem. Look at the images
when I approach a slope, the texture is painted on the air.

Any suggestions?

[kjuanlu]

Solved¡¡¡

I changed to GLES2, I learned OpenGL ES shading languaje, and I wrote a shader for projective Texturing.
Then I extend the shader for blending with a diffuse image, and I will blend with a lightmap too.

I pass a param to a shader in every frame with this:
ps_params->setNamedConstant("texViewProjMatrix",mDecalFrustum->getProjectionMatrix() * mDecalFrustum->getViewMatrix());

This is the result:


When I´ve time, I will write a wiki for projective decals for iPhone GLES2 with shaders