diff options
Diffstat (limited to 'intern/cycles/kernel/svm/fresnel.h')
-rw-r--r-- | intern/cycles/kernel/svm/fresnel.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/intern/cycles/kernel/svm/fresnel.h b/intern/cycles/kernel/svm/fresnel.h new file mode 100644 index 00000000000..9dd68c3e38f --- /dev/null +++ b/intern/cycles/kernel/svm/fresnel.h @@ -0,0 +1,84 @@ +/* + * Copyright 2011-2013 Blender Foundation + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#pragma once + +CCL_NAMESPACE_BEGIN + +/* Fresnel Node */ + +ccl_device_noinline void svm_node_fresnel(ccl_private ShaderData *sd, + ccl_private float *stack, + uint ior_offset, + uint ior_value, + uint node) +{ + uint normal_offset, out_offset; + svm_unpack_node_uchar2(node, &normal_offset, &out_offset); + float eta = (stack_valid(ior_offset)) ? stack_load_float(stack, ior_offset) : + __uint_as_float(ior_value); + float3 normal_in = stack_valid(normal_offset) ? stack_load_float3(stack, normal_offset) : sd->N; + + eta = fmaxf(eta, 1e-5f); + eta = (sd->flag & SD_BACKFACING) ? 1.0f / eta : eta; + + float f = fresnel_dielectric_cos(dot(sd->I, normal_in), eta); + + stack_store_float(stack, out_offset, f); +} + +/* Layer Weight Node */ + +ccl_device_noinline void svm_node_layer_weight(ccl_private ShaderData *sd, + ccl_private float *stack, + uint4 node) +{ + uint blend_offset = node.y; + uint blend_value = node.z; + + uint type, normal_offset, out_offset; + svm_unpack_node_uchar3(node.w, &type, &normal_offset, &out_offset); + + float blend = (stack_valid(blend_offset)) ? stack_load_float(stack, blend_offset) : + __uint_as_float(blend_value); + float3 normal_in = (stack_valid(normal_offset)) ? stack_load_float3(stack, normal_offset) : + sd->N; + + 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, normal_in), eta); + } + else { + f = fabsf(dot(sd->I, normal_in)); + + if (blend != 0.5f) { + blend = clamp(blend, 0.0f, 1.0f - 1e-5f); + 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 |