WorldViz User Forum - multitex fragment shader issue for different sized textures

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- - multitex fragment shader issue for different sized textures (https://forum.worldviz.com/showthread.php?t=5568)

multitex fragment shader issue for different sized textures

Hi,

I am trying to blend an algae texture to a sea floor texture. The algae texture file is a 512x512 jpg image. I am retrieving the other texture from our ocean osgb model. This texture is a 1024x1024 baked into the model.

I have tried four ways (see below), but unfortunately, none works!
All are shaders, except for the first.

1. Using texblend - this gives some kind of blending, but it is non-uniform and not upto our expectations.
2. Using the texBlendFP.frag shader - the first texture do not show up at all.
3. Using the custom blend shader from \examples\shader\tutorial_multiTexture.py - the first texture do not show up at all.
4. Using the code from multiTexture.py (Tutorial: Multi-texturing) - strangely, same result as in option 1 above!

I have attached the py file in txt format here.
Any suggestions on how to get this to work?

Thank you!

It will be best if you can post example Vizard code that reproduces the issue and can be run directly.

Code:

import viz

import vizfx



terrain = vizfx.addChild('blendTest.OSGB')

viz.go()



viz.MainView.setPosition([58.64860153198242, 0.0, -6.446604251861572])



algaeTexture = viz.addTexture('algae_texture3.jpg', type=viz.TEX_2D, wrap=viz.REPEAT)

# Create shader effect that blends textures and applies to diffuse color

code = """

Effect "Texture Blend" {



Float BlendAmount { value 0 }

Texture2D Texture1 { unit 0 }

Texture2D Texture2 { unit 1 }



Shader {



        BEGIN Material

        m.diffuse = mix( texture2D( Texture1, uvTexture1).rgb, texture2D( Texture2, uvTexture2).rgb, BlendAmount);

        END



}



}

"""

texBlendEffect = viz.addEffect(code)



itemFromTerrain = terrain.getChild('Terrain_Zone03')

oldTex = itemFromTerrain.getTexture()

itemFromTerrain.texture(oldTex)

itemFromTerrain.texture(algaeTexture, '', unit=1)

itemFromTerrain.apply(texBlendEffect)

itemFromTerrain.setUniformFloat('BlendAmount', 0.0)



slider = viz.addSlider(pos=[0.5,0.1,0])



def setBlendAmount2(blendRatioFromSlider):

        global itemFromTerrain

        itemFromTerrain.setUniformFloat('BlendAmount', blendRatioFromSlider)

vizact.onslider(slider, setBlendAmount2)



#

I couldn't find a Vizard resource to recreate this issue, so here is a link to download a zip of my shortest test py file with the terrain osgb and the algae jpg that I am trying to blend - https://stanford.box.com/s/5myna254j...5mkbkfmzdjug28.

Jeff, just letting you know that I was able to solve the problem, with the help of Jorge, a Worldviz 3D artist. The baked texture in the terrain was a blend of two textures and a masked texture. I think he used the "render to texture" feature in 3DS max to export all of it to a single texture, which I used instead of retrieving the texture1 from the terrain at runtime. Then I blended it using the algae texture in the unit 1 of multitexturing.

Thank you.