dd51c8660b
Check was misc-const-correctness, combined with readability-isolate-declaration as suggested by the docs. Temporarily clang-format "QualifierAlignment: Left" was used to get consistency with the prevailing order of keywords. Pull Request: https://projects.blender.org/blender/blender/pulls/132361
88 lines
2.8 KiB
C
88 lines
2.8 KiB
C
/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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*
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* SPDX-License-Identifier: Apache-2.0 */
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/* Volume Primitive
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*
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* Volumes are just regions inside meshes with the mesh surface as boundaries.
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* There isn't as much data to access as for surfaces, there is only a position
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* to do lookups in 3D voxel or procedural textures.
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*
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* 3D voxel textures can be assigned as attributes per mesh, which means the
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* same shader can be used for volume objects with different densities, etc. */
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#pragma once
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#include "kernel/globals.h"
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#include "kernel/image.h"
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#include "kernel/geom/attribute.h"
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#include "kernel/geom/object.h"
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CCL_NAMESPACE_BEGIN
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#ifdef __VOLUME__
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/* Return position normalized to 0..1 in mesh bounds */
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ccl_device_inline float3 volume_normalized_position(KernelGlobals kg,
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const ccl_private ShaderData *sd,
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float3 P)
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{
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/* todo: optimize this so it's just a single matrix multiplication when
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* possible (not motion blur), or perhaps even just translation + scale */
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const AttributeDescriptor desc = find_attribute(kg, sd, ATTR_STD_GENERATED_TRANSFORM);
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object_inverse_position_transform(kg, sd, &P);
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if (desc.offset != ATTR_STD_NOT_FOUND) {
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const Transform tfm = primitive_attribute_matrix(kg, desc);
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P = transform_point(&tfm, P);
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}
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return P;
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}
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ccl_device float volume_attribute_value_to_float(const float4 value)
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{
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return average(make_float3(value));
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}
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ccl_device float volume_attribute_value_to_alpha(const float4 value)
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{
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return value.w;
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}
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ccl_device float3 volume_attribute_value_to_float3(const float4 value)
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{
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if (value.w > 1e-6f && value.w != 1.0f) {
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/* For RGBA colors, unpremultiply after interpolation. */
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return make_float3(value) / value.w;
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}
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return make_float3(value);
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}
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ccl_device float4 volume_attribute_float4(KernelGlobals kg,
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const ccl_private ShaderData *sd,
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const AttributeDescriptor desc)
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{
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if (desc.element & (ATTR_ELEMENT_OBJECT | ATTR_ELEMENT_MESH)) {
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return kernel_data_fetch(attributes_float4, desc.offset);
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}
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if (desc.element == ATTR_ELEMENT_VOXEL) {
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/* todo: optimize this so we don't have to transform both here and in
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* kernel_tex_image_interp_3d when possible. Also could optimize for the
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* common case where transform is translation/scale only. */
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float3 P = sd->P;
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object_inverse_position_transform(kg, sd, &P);
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const InterpolationType interp = (sd->flag & SD_VOLUME_CUBIC) ? INTERPOLATION_CUBIC :
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INTERPOLATION_NONE;
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return kernel_tex_image_interp_3d(kg, desc.offset, P, interp);
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}
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return zero_float4();
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}
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#endif
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CCL_NAMESPACE_END
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