Hello folks,

i’ve got the following problem:

I actually working on my bachelorthesis. My title is “Displacement Mapping with Tessellation”.

I am almost finished, but i need the numbers of triangles/vertices to do some comparisons.

I am working with the JMonkey3-Engine(JME3) and OpenGL under windows. JME3 provides a statsView, the problem there is that it only gives you the number of your object you created.

For example: I create a triangle so I have 3 Vertices and 1 Triangle, now I start my programm and raise the TessellationLevel, but the counts are not increasing because the Tessellation is in the GPU.

Now there is my question, how can I get the numbers?

Here are my Shader Stages (a simple one, without DisplacemetMapping):

```
//vertex-shader
uniform mat4 g_WorldMatrix;
in vec3 inPosition;
out vec3 vPosition;
void main() {
vec4 position = g_WorldMatrix * vec4(inPosition, 1.0);
position /= position.w;
vPosition = position.xyz;
}
//TC
layout(vertices = 3) out;
in vec3 vPosition[];
out vec3 tcPosition[];
uniform float m_InnerTess;
uniform float m_OuterTess;
void main()
{
tcPosition[gl_InvocationID] = vPosition[gl_InvocationID];
if (gl_InvocationID == 0) {
gl_TessLevelInner[0] = m_InnerTess;
gl_TessLevelOuter[0] = m_OuterTess;
gl_TessLevelOuter[1] = m_OuterTess;
gl_TessLevelOuter[2] = m_OuterTess;
}
}
//TES
layout(triangles, equal_spacing, ccw) in;
in vec3 tcPosition[];
out vec3 tePosition;
uniform mat4 g_ViewProjectionMatrix;
vec3 interpolate3D(vec3 v0, vec3 v1, vec3 v2)
{
return vec3(gl_TessCoord.x) * v0 + vec3(gl_TessCoord.y) * v1 + vec3(gl_TessCoord.z) * v2;
}
void main()
{
tePosition = interpolate3D(tcPosition[0], tcPosition[1], tcPosition[2]);
gl_Position = g_ViewProjectionMatrix * vec4(tePosition, 1.0);
}
//FS
out vec4 outFragColor;
void main() {
vec4 color = vec4(1.0);
outFragColor = color;
}
```

That is my code for a single triangle to tessellate, by giving him the number of the tessellationlevel.

I guess i have to look at the TES because he gives me the vertices to draw.

If you have any more question, feel free to ask, I hope you guys can help me.