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author | Sv. Lockal <lockalsash@gmail.com> | 2015-05-05 09:11:54 +0300 |
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committer | Sv. Lockal <lockalsash@gmail.com> | 2015-05-05 09:11:54 +0300 |
commit | 7201f6d14c0161ad9a0d4143d1c5caf872e0d93e (patch) | |
tree | cf3d0b69ed4a1ad54a42c4c9322df396ab3e2a0e /intern/cycles/render/nodes.cpp | |
parent | 22bbd1c51219aafb40adb3e9a206f660a621fd70 (diff) |
Cycles: Use curve approximation for blackbody instead of lookup table
Now we calculate color in range 800..12000 using an approximation a/x+bx+c for R and G and ((at + b)t + c)t + d) for B.
Max absolute error for RGB for non-lut function is less than 0.0001, which is enough to get the same 8 bit/channel color as for OSL with a noticeable performance difference.
However there is a slight visible difference between previous non-OSL implementation because of lookup table interpolation and offset-by-one mistake.
The previous implementation gave black color outside of soft range (t > 12000), now it gives the same color as for 12000.
Also blackbody node without input connected is being converted to value input at shader compile time.
Reviewers: dingto, sergey
Reviewed By: dingto
Subscribers: nutel, brecht, juicyfruit
Differential Revision: https://developer.blender.org/D1280
Diffstat (limited to 'intern/cycles/render/nodes.cpp')
-rw-r--r-- | intern/cycles/render/nodes.cpp | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp index 8529855ff2e..d17d531aa77 100644 --- a/intern/cycles/render/nodes.cpp +++ b/intern/cycles/render/nodes.cpp @@ -3652,9 +3652,17 @@ void BlackbodyNode::compile(SVMCompiler& compiler) ShaderInput *temperature_in = input("Temperature"); ShaderOutput *color_out = output("Color"); - compiler.stack_assign(temperature_in); compiler.stack_assign(color_out); - compiler.add_node(NODE_BLACKBODY, temperature_in->stack_offset, color_out->stack_offset); + + if(temperature_in->link == NULL) { + float3 color = svm_math_blackbody_color(temperature_in->value.x); + compiler.add_node(NODE_VALUE_V, color_out->stack_offset); + compiler.add_node(NODE_VALUE_V, color); + } + else { + compiler.stack_assign(temperature_in); + compiler.add_node(NODE_BLACKBODY, temperature_in->stack_offset, color_out->stack_offset); + } } void BlackbodyNode::compile(OSLCompiler& compiler) |