Clear Shader Cache

Scripting Issues
1

I am developing some shader code and I don’t want to close the panda window and restart again after I change the shader program.

I call clearShader and also ShaderPool.releaseAllShaders() to unload the shaders after I modify the shader code. But it does not work all the time. What is the proper way to do so ? Thank you.

2

Hmm, panda should automatically recompile the shader if it has changed.
How are you creating your shaders? Using Shader.load or using Shader.make(shadercontents) ?

3

I use loader.loadShader.

4

Try sh = Shader.load(Filename(blah)) then. Or Shader.make if you have the shader stored in a string. I believe this method doesn’t use caching.

5

I try also Shader.load. The result is the same.

If I get the reference count of the shader before I called clearShader, it is 3. After I called clearShader, it is 2. Somehow it is locked ?

Is it possible a bug on Windows XP platform ?

6

Advance the frame, call base.graphicsEngine.renderFrame() once or twice after release.

7

It does not help either.

8

It does work, unless there are some references of the shader somewhere in your script, eg. if you save it in some attributes.

9

I re-test several other sample programs and most of them work. Only one complicated one is not working. I will recheck and track it down later. Thank you.

10

This is my test :

from direct.showbase.DirectObject import DirectObject
from pandac.PandaModules import ShaderPool
import direct.directbase.DirectStart

def changeShader():
    global color
    # If sh is in global namespace, it will hold the shader's reference,
    # so its refcount won't reach 0, and won't be released.
    # Comment this to see the difference.
#     global sh
    color = not color
    code = '''//Cg
void vshader(float4 vtx_position : POSITION,
             uniform float4x4 mat_modelproj,
             out float4 l_position : POSITION)
  { l_position=mul(mat_modelproj, vtx_position); }

void fshader(out float4 o_color:COLOR)
  { o_color=%i; }'''%color
    print '\ncolor : %i'%color
    f=open(shaderName,'w')
    f.write(code)
    f.close()
    sphere.clearShader()
    # release all shaders
    ShaderPool.releaseAllShaders()
    # it seems the release is queued until next frame, so force render now
    base.graphicsEngine.renderFrame()
    # reload & apply
    sh=loader.loadShader(shaderName)
    sphere.setShader(sh)

sphere=loader.loadModel('misc/sphere')
sphere.reparentTo(render)
sphere.setY(5)

shaderName='shader-test.cg'
color=0

DO=DirectObject()
DO.accept('space',changeShader)

changeShader()
run()

Press SPACE to toggle the white or black color.

11

My problem is in the ocean2 demo inside demomaster that I just posted
discourse.panda3d.org/viewtopic.php?t=5915

If I select Ocean2, and then select IDLE (or switch to another demo), then I edit the share/shaders/ocean2.sha, and then select Ocean2 demo again. The new changes are not applied. I have to quit the whole application and start again for it to work.

This problem does not happen on other parts of the program.