V2和V2CPP的脸部渲染框线问题

[FT4827695]

绘制出的人物面部的眼睛和嘴巴会有细框线，特别是在眨眼和闭眼时更加明显，用的GLFW。

绘制主窗口模型

self.model.Update()
gl.glPushAttrib(gl.GL_CURRENT_BIT | gl.GL_ENABLE_BIT | gl.GL_POLYGON_BIT | gl.GL_COLOR_BUFFER_BIT)
gl.glUseProgram(0)
gl.glDisable(gl.GL_DEPTH_TEST)
gl.glDisable(gl.GL_CULL_FACE)
gl.glEnable(gl.GL_BLEND)
gl.glBlendFuncSeparate(gl.GL_ONE, gl.GL_ONE_MINUS_SRC_ALPHA, gl.GL_ONE, gl.GL_ONE_MINUS_SRC_ALPHA)
self.model.Draw()
gl.glPopAttrib()

win_w, win_h = glfw.get_window_size(self.window)
self.bubble.draw(win_w, win_h)

[FT4827695]

大致搞清楚了，是OpenGL在进行纹理采样时的RGB通道没乘以 Alpha，着色器接收的是被污染的边界插值。目前的有效做法是手动预乘纹理数据，需要在调用 load_model_json()之后预乘纹理self._premultiply_textures()，同时要删除draw_param_opengl里的预乘以避免二次叠加，删除掉self.aM的smpColor.rgb = smpColor.rgb * smpColor.a和self.aJ的col_formask.rgb = col_formask.rgb * col_formask.a。下面的这段预乘代码参考了WebGL的处理方式。

def _premultiply_textures(self):
if self._model_json_dict is None:
return
textures = self._model_json_dict.get("textures", [])
if not textures:
return

if hasattr(self.model, 'live2DModel') and hasattr(self.model.live2DModel, 'getDrawParam'):
    draw_param = self.model.live2DModel.getDrawParam()
else:
    return

if draw_param is None:
    return

if len(draw_param.textures) < len(textures):
    return

for i, tex_file in enumerate(textures):
    tex_path = os.path.join(MODEL_DIR, tex_file)
    if not os.path.exists(tex_path):
        continue

    img = Image.open(tex_path).convert('RGBA')
    data = np.array(img, dtype=np.uint8)
    r, g, b, a = np.split(data, 4, axis=-1)
    r_f = r.astype(np.float32) / 255.0
    g_f = g.astype(np.float32) / 255.0
    b_f = b.astype(np.float32) / 255.0
    a_f = a.astype(np.float32) / 255.0
    r_pre = (r_f * a_f * 255).astype(np.uint8)
    g_pre = (g_f * a_f * 255).astype(np.uint8)
    b_pre = (b_f * a_f * 255).astype(np.uint8)
    pre_data = np.concatenate([r_pre, g_pre, b_pre, a], axis=-1)

    old_id = draw_param.textures[i] if i < len(draw_param.textures) else None
    if old_id is not None:
        gl.glDeleteTextures([old_id])

    new_id = gl.glGenTextures(1)
    gl.glBindTexture(gl.GL_TEXTURE_2D, new_id)
    gl.glTexImage2D(gl.GL_TEXTURE_2D, 0, gl.GL_RGBA,
                    img.width, img.height, 0,
                    gl.GL_RGBA, gl.GL_UNSIGNED_BYTE, pre_data)
    gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MIN_FILTER, gl.GL_LINEAR)
    gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MAG_FILTER, gl.GL_LINEAR)
    gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_S, gl.GL_CLAMP_TO_EDGE)
    gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_T, gl.GL_CLAMP_TO_EDGE)
    gl.glBindTexture(gl.GL_TEXTURE_2D, 0)

    draw_param.setTexture(i, new_id)