How to use billboard shader?

[omid3098]

I checked previous versions(since 2.14) but I could not make billboard shader work.. and actually I could not understand how auto billboard generator(used for vegetation system) use this shader..

so.. please help me!

[macklebee]

I had posted this for CopperCircle last week, but its gone now...

 

First, unpack the shaders.pak, and change the mesh.vert to include these lines:

#ifdef LW_BILLBOARD
     	vertexcameraposition = (gl_ModelViewProjectionMatrix * mat[3]) + vec4(gl_Vertex.x,gl_Vertex.y*(buffersize.x/buffersize.y),0.0,0.0);
#endif

 

Place them after the sway if-defined statement right after the vertexcameraposition and before the textcoord0 statements:

...

...

#ifdef LW_SWAY

float seed = mod(apptime / 100.0 * 0.25,360.0);

seed += mat[3].x*33.0 + mat[3].y*67.8 + mat[3].z*123.5;

seed += gl_Vertex.x + gl_Vertex.y + gl_Vertex.z;

vec4 movement = vec4( vec3( gl_Color.x * gl_Normal * LW_SWAY * (sin(seed)+0.25*cos(seed*5.2+3.2)) ),0.0);

modelvertex += movement;

fragcolor = color;

#endif

 

vertexposition = modelvertex.xyz;

vertexcameraposition = gl_ModelViewProjectionMatrix * modelvertex;

 

#ifdef LW_BILLBOARD

vertexcameraposition = (gl_ModelViewProjectionMatrix * mat[3]) + vec4(gl_Vertex.x,gl_Vertex.y*(buffersize.x/buffersize.y),0.0,0.0);

#endif

 

 

texcoord0=gl_MultiTexCoord0.xy;

texcoord1=gl_MultiTexCoord1.xy;

...

...

 

Here is an example billboard that you can drop in the editor:

 

Note: Make sure you only have one mesh.vert inside your SDK or you cannot guarantee what file the engine will grab using the abstract file method.

[omid3098]

Thank you very much!

let me check it..

I found that lots of speedtree leaves have billboard shader. and as my trees are little **** right now(!) I have to check them with this technique..

[macklebee]

For leaves on a tree, i do not think a billboard is what you want to use. A billboard makes the image always face the camera... a leaf doesn't do that.

 

You would want to use a plane mesh that has the leaf texture on it, and then use something like this for a material file:

texture0="abstract::oak_leaf.dds"
texture1="abstract::oak_leafdot3.dds"
bumpscale=0.3
cullface=0
shader="abstract::mesh_diffuse_bumpmap_sway.vert","abstract::mesh_diffuse_bumpmap_alphatest.frag"
shadowshader="abstract::mesh_shadow_sway.vert","abstract::mesh_shadow.frag"

[omid3098]

yes, I know.. it's what I'm using right now.. but speedtree uses exactly billboards for leaves in some of its trees..I checked many tutorials about making trees and some of them used this technique too..