diff options
Diffstat (limited to 'intern/cycles/kernel/svm/svm_fresnel.h')
-rw-r--r-- | intern/cycles/kernel/svm/svm_fresnel.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/intern/cycles/kernel/svm/svm_fresnel.h b/intern/cycles/kernel/svm/svm_fresnel.h new file mode 100644 index 00000000000..7684eabeecb --- /dev/null +++ b/intern/cycles/kernel/svm/svm_fresnel.h @@ -0,0 +1,70 @@ +/* + * Copyright 2011, Blender Foundation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +CCL_NAMESPACE_BEGIN + +/* Fresnel Node */ + +__device void svm_node_fresnel(ShaderData *sd, float *stack, uint ior_offset, uint ior_value, uint out_offset) +{ + float eta = (stack_valid(ior_offset))? stack_load_float(stack, ior_offset): __int_as_float(ior_value); + eta = fmaxf(eta, 1.0f + 1e-5f); + eta = (sd->flag & SD_BACKFACING)? 1.0f/eta: eta; + + float f = fresnel_dielectric_cos(dot(sd->I, sd->N), eta); + + stack_store_float(stack, out_offset, f); +} + +/* Blend Weight Node */ + +__device void svm_node_layer_weight(ShaderData *sd, float *stack, uint4 node) +{ + uint blend_offset = node.y; + uint blend_value = node.z; + float blend = (stack_valid(blend_offset))? stack_load_float(stack, blend_offset): __int_as_float(blend_value); + + uint type, out_offset; + decode_node_uchar4(node.w, &type, &out_offset, NULL, NULL); + + float f; + + if(type == NODE_LAYER_WEIGHT_FRESNEL) { + float eta = fmaxf(1.0f - blend, 1e-5f); + eta = (sd->flag & SD_BACKFACING)? eta: 1.0f/eta; + + f = fresnel_dielectric_cos(dot(sd->I, sd->N), eta); + } + else { + f = fabsf(dot(sd->I, sd->N)); + + if(blend != 0.5f) { + blend = clamp(blend, 0.0f, 1.0f); + blend = (blend < 0.5f)? 2.0f*blend: 0.5f/(1.0f - blend); + + f = powf(f, blend); + } + + f = 1.0f - f; + } + + stack_store_float(stack, out_offset, f); +} + +CCL_NAMESPACE_END + |